2018-08-17 00:23:53 +09:00
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// SPDX-License-Identifier: GPL-2.0
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tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
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/*
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* trace_events_hist - trace event hist triggers
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*
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* Copyright (C) 2015 Tom Zanussi <tom.zanussi@linux.intel.com>
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*/
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#include <linux/module.h>
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#include <linux/kallsyms.h>
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2019-10-12 06:22:50 +09:00
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#include <linux/security.h>
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tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
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#include <linux/mutex.h>
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#include <linux/slab.h>
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#include <linux/stacktrace.h>
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2017-02-04 09:27:20 +09:00
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#include <linux/rculist.h>
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tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
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#include <linux/tracefs.h>
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tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
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2019-07-12 10:53:08 +09:00
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/* for gfp flag names */
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#include <linux/trace_events.h>
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#include <trace/events/mmflags.h>
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tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
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#include "tracing_map.h"
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#include "trace.h"
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2018-11-05 18:03:33 +09:00
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#include "trace_dynevent.h"
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tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
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tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
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#define SYNTH_SYSTEM "synthetic"
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#define SYNTH_FIELDS_MAX 16
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#define STR_VAR_LEN_MAX 32 /* must be multiple of sizeof(u64) */
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2019-04-01 08:48:17 +09:00
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#define ERRORS \
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C(NONE, "No error"), \
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C(DUPLICATE_VAR, "Variable already defined"), \
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C(VAR_NOT_UNIQUE, "Variable name not unique, need to use fully qualified name (subsys.event.var) for variable"), \
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C(TOO_MANY_VARS, "Too many variables defined"), \
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C(MALFORMED_ASSIGNMENT, "Malformed assignment"), \
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C(NAMED_MISMATCH, "Named hist trigger doesn't match existing named trigger (includes variables)"), \
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C(TRIGGER_EEXIST, "Hist trigger already exists"), \
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C(TRIGGER_ENOENT_CLEAR, "Can't clear or continue a nonexistent hist trigger"), \
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C(SET_CLOCK_FAIL, "Couldn't set trace_clock"), \
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C(BAD_FIELD_MODIFIER, "Invalid field modifier"), \
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C(TOO_MANY_SUBEXPR, "Too many subexpressions (3 max)"), \
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C(TIMESTAMP_MISMATCH, "Timestamp units in expression don't match"), \
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C(TOO_MANY_FIELD_VARS, "Too many field variables defined"), \
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C(EVENT_FILE_NOT_FOUND, "Event file not found"), \
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C(HIST_NOT_FOUND, "Matching event histogram not found"), \
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C(HIST_CREATE_FAIL, "Couldn't create histogram for field"), \
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C(SYNTH_VAR_NOT_FOUND, "Couldn't find synthetic variable"), \
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C(SYNTH_EVENT_NOT_FOUND,"Couldn't find synthetic event"), \
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C(SYNTH_TYPE_MISMATCH, "Param type doesn't match synthetic event field type"), \
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C(SYNTH_COUNT_MISMATCH, "Param count doesn't match synthetic event field count"), \
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C(FIELD_VAR_PARSE_FAIL, "Couldn't parse field variable"), \
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C(VAR_CREATE_FIND_FAIL, "Couldn't create or find variable"), \
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C(ONX_NOT_VAR, "For onmax(x) or onchange(x), x must be a variable"), \
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C(ONX_VAR_NOT_FOUND, "Couldn't find onmax or onchange variable"), \
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C(ONX_VAR_CREATE_FAIL, "Couldn't create onmax or onchange variable"), \
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C(FIELD_VAR_CREATE_FAIL,"Couldn't create field variable"), \
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C(TOO_MANY_PARAMS, "Too many action params"), \
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C(PARAM_NOT_FOUND, "Couldn't find param"), \
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C(INVALID_PARAM, "Invalid action param"), \
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C(ACTION_NOT_FOUND, "No action found"), \
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C(NO_SAVE_PARAMS, "No params found for save()"), \
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C(TOO_MANY_SAVE_ACTIONS,"Can't have more than one save() action per hist"), \
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C(ACTION_MISMATCH, "Handler doesn't support action"), \
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C(NO_CLOSING_PAREN, "No closing paren found"), \
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C(SUBSYS_NOT_FOUND, "Missing subsystem"), \
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C(INVALID_SUBSYS_EVENT, "Invalid subsystem or event name"), \
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2019-04-19 00:18:51 +09:00
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C(INVALID_REF_KEY, "Using variable references in keys not supported"), \
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2019-04-01 08:48:17 +09:00
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C(VAR_NOT_FOUND, "Couldn't find variable"), \
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2021-07-28 07:55:43 +09:00
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C(FIELD_NOT_FOUND, "Couldn't find field"), \
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C(INVALID_STR_OPERAND, "String type can not be an operand in expression"),
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2019-04-01 08:48:17 +09:00
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#undef C
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#define C(a, b) HIST_ERR_##a
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enum { ERRORS };
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#undef C
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#define C(a, b) b
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static const char *err_text[] = { ERRORS };
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tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
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struct hist_field;
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|
|
2018-01-16 11:51:54 +09:00
|
|
|
typedef u64 (*hist_field_fn_t) (struct hist_field *field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
2017-09-23 04:58:23 +09:00
|
|
|
#define HIST_FIELD_OPERANDS_MAX 2
|
2018-01-16 11:51:49 +09:00
|
|
|
#define HIST_FIELDS_MAX (TRACING_MAP_FIELDS_MAX + TRACING_MAP_VARS_MAX)
|
2018-01-16 11:51:57 +09:00
|
|
|
#define HIST_ACTIONS_MAX 8
|
2018-01-16 11:51:49 +09:00
|
|
|
|
2018-01-16 11:51:52 +09:00
|
|
|
enum field_op_id {
|
|
|
|
|
FIELD_OP_NONE,
|
|
|
|
|
FIELD_OP_PLUS,
|
|
|
|
|
FIELD_OP_MINUS,
|
|
|
|
|
FIELD_OP_UNARY_MINUS,
|
|
|
|
|
};
|
|
|
|
|
|
2018-12-19 05:33:26 +09:00
|
|
|
/*
|
|
|
|
|
* A hist_var (histogram variable) contains variable information for
|
|
|
|
|
* hist_fields having the HIST_FIELD_FL_VAR or HIST_FIELD_FL_VAR_REF
|
|
|
|
|
* flag set. A hist_var has a variable name e.g. ts0, and is
|
|
|
|
|
* associated with a given histogram trigger, as specified by
|
|
|
|
|
* hist_data. The hist_var idx is the unique index assigned to the
|
|
|
|
|
* variable by the hist trigger's tracing_map. The idx is what is
|
|
|
|
|
* used to set a variable's value and, by a variable reference, to
|
|
|
|
|
* retrieve it.
|
|
|
|
|
*/
|
2018-01-16 11:51:49 +09:00
|
|
|
struct hist_var {
|
|
|
|
|
char *name;
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
|
|
|
|
unsigned int idx;
|
|
|
|
|
};
|
2017-09-23 04:58:23 +09:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
struct hist_field {
|
|
|
|
|
struct ftrace_event_field *field;
|
|
|
|
|
unsigned long flags;
|
|
|
|
|
hist_field_fn_t fn;
|
tracing: Fix histogram code when expression has same var as value
commit 8bcebc77e85f3d7536f96845a0fe94b1dddb6af0 upstream.
While working on a tool to convert SQL syntex into the histogram language of
the kernel, I discovered the following bug:
# echo 'first u64 start_time u64 end_time pid_t pid u64 delta' >> synthetic_events
# echo 'hist:keys=pid:start=common_timestamp' > events/sched/sched_waking/trigger
# echo 'hist:keys=next_pid:delta=common_timestamp-$start,start2=$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger
Would not display any histograms in the sched_switch histogram side.
But if I were to swap the location of
"delta=common_timestamp-$start" with "start2=$start"
Such that the last line had:
# echo 'hist:keys=next_pid:start2=$start,delta=common_timestamp-$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger
The histogram works as expected.
What I found out is that the expressions clear out the value once it is
resolved. As the variables are resolved in the order listed, when
processing:
delta=common_timestamp-$start
The $start is cleared. When it gets to "start2=$start", it errors out with
"unresolved symbol" (which is silent as this happens at the location of the
trace), and the histogram is dropped.
When processing the histogram for variable references, instead of adding a
new reference for a variable used twice, use the same reference. That way,
not only is it more efficient, but the order will no longer matter in
processing of the variables.
From Tom Zanussi:
"Just to clarify some more about what the problem was is that without
your patch, we would have two separate references to the same variable,
and during resolve_var_refs(), they'd both want to be resolved
separately, so in this case, since the first reference to start wasn't
part of an expression, it wouldn't get the read-once flag set, so would
be read normally, and then the second reference would do the read-once
read and also be read but using read-once. So everything worked and
you didn't see a problem:
from: start2=$start,delta=common_timestamp-$start
In the second case, when you switched them around, the first reference
would be resolved by doing the read-once, and following that the second
reference would try to resolve and see that the variable had already
been read, so failed as unset, which caused it to short-circuit out and
not do the trigger action to generate the synthetic event:
to: delta=common_timestamp-$start,start2=$start
With your patch, we only have the single resolution which happens
correctly the one time it's resolved, so this can't happen."
Link: https://lore.kernel.org/r/20200116154216.58ca08eb@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: 067fe038e70f6 ("tracing: Add variable reference handling to hist triggers")
Reviewed-by: Tom Zanuss <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-21 03:07:31 +09:00
|
|
|
unsigned int ref;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
unsigned int size;
|
2016-03-04 03:54:44 +09:00
|
|
|
unsigned int offset;
|
2017-09-23 04:58:23 +09:00
|
|
|
unsigned int is_signed;
|
2018-01-16 11:51:55 +09:00
|
|
|
const char *type;
|
2017-09-23 04:58:23 +09:00
|
|
|
struct hist_field *operands[HIST_FIELD_OPERANDS_MAX];
|
2018-01-16 11:51:47 +09:00
|
|
|
struct hist_trigger_data *hist_data;
|
2018-12-19 05:33:26 +09:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Variable fields contain variable-specific info in var.
|
|
|
|
|
*/
|
2018-01-16 11:51:49 +09:00
|
|
|
struct hist_var var;
|
2018-01-16 11:51:52 +09:00
|
|
|
enum field_op_id operator;
|
2018-01-16 11:51:56 +09:00
|
|
|
char *system;
|
|
|
|
|
char *event_name;
|
2018-12-19 05:33:26 +09:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* The name field is used for EXPR and VAR_REF fields. VAR
|
|
|
|
|
* fields contain the variable name in var.name.
|
|
|
|
|
*/
|
2018-01-16 11:51:52 +09:00
|
|
|
char *name;
|
2018-12-19 05:33:26 +09:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* When a histogram trigger is hit, if it has any references
|
|
|
|
|
* to variables, the values of those variables are collected
|
|
|
|
|
* into a var_ref_vals array by resolve_var_refs(). The
|
|
|
|
|
* current value of each variable is read from the tracing_map
|
|
|
|
|
* using the hist field's hist_var.idx and entered into the
|
|
|
|
|
* var_ref_idx entry i.e. var_ref_vals[var_ref_idx].
|
|
|
|
|
*/
|
2018-01-16 11:51:56 +09:00
|
|
|
unsigned int var_ref_idx;
|
|
|
|
|
bool read_once;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
};
|
|
|
|
|
|
2018-01-16 11:51:54 +09:00
|
|
|
static u64 hist_field_none(struct hist_field *field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
2016-03-04 03:54:52 +09:00
|
|
|
{
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:54 +09:00
|
|
|
static u64 hist_field_counter(struct hist_field *field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
{
|
|
|
|
|
return 1;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:54 +09:00
|
|
|
static u64 hist_field_string(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
{
|
|
|
|
|
char *addr = (char *)(event + hist_field->field->offset);
|
|
|
|
|
|
|
|
|
|
return (u64)(unsigned long)addr;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:54 +09:00
|
|
|
static u64 hist_field_dynstring(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
2016-03-04 03:54:53 +09:00
|
|
|
{
|
|
|
|
|
u32 str_item = *(u32 *)(event + hist_field->field->offset);
|
|
|
|
|
int str_loc = str_item & 0xffff;
|
|
|
|
|
char *addr = (char *)(event + str_loc);
|
|
|
|
|
|
|
|
|
|
return (u64)(unsigned long)addr;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:54 +09:00
|
|
|
static u64 hist_field_pstring(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
2016-03-04 03:54:53 +09:00
|
|
|
{
|
|
|
|
|
char **addr = (char **)(event + hist_field->field->offset);
|
|
|
|
|
|
|
|
|
|
return (u64)(unsigned long)*addr;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:54 +09:00
|
|
|
static u64 hist_field_log2(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
2016-03-04 03:55:02 +09:00
|
|
|
{
|
2017-09-23 04:58:23 +09:00
|
|
|
struct hist_field *operand = hist_field->operands[0];
|
|
|
|
|
|
2018-01-16 11:51:54 +09:00
|
|
|
u64 val = operand->fn(operand, elt, rbe, event);
|
2016-03-04 03:55:02 +09:00
|
|
|
|
|
|
|
|
return (u64) ilog2(roundup_pow_of_two(val));
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:54 +09:00
|
|
|
static u64 hist_field_plus(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
2018-01-16 11:51:52 +09:00
|
|
|
{
|
|
|
|
|
struct hist_field *operand1 = hist_field->operands[0];
|
|
|
|
|
struct hist_field *operand2 = hist_field->operands[1];
|
|
|
|
|
|
2018-01-16 11:51:54 +09:00
|
|
|
u64 val1 = operand1->fn(operand1, elt, rbe, event);
|
|
|
|
|
u64 val2 = operand2->fn(operand2, elt, rbe, event);
|
2018-01-16 11:51:52 +09:00
|
|
|
|
|
|
|
|
return val1 + val2;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:54 +09:00
|
|
|
static u64 hist_field_minus(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
2018-01-16 11:51:52 +09:00
|
|
|
{
|
|
|
|
|
struct hist_field *operand1 = hist_field->operands[0];
|
|
|
|
|
struct hist_field *operand2 = hist_field->operands[1];
|
|
|
|
|
|
2018-01-16 11:51:54 +09:00
|
|
|
u64 val1 = operand1->fn(operand1, elt, rbe, event);
|
|
|
|
|
u64 val2 = operand2->fn(operand2, elt, rbe, event);
|
2018-01-16 11:51:52 +09:00
|
|
|
|
|
|
|
|
return val1 - val2;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:54 +09:00
|
|
|
static u64 hist_field_unary_minus(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
2018-01-16 11:51:52 +09:00
|
|
|
{
|
|
|
|
|
struct hist_field *operand = hist_field->operands[0];
|
|
|
|
|
|
2018-01-16 11:51:54 +09:00
|
|
|
s64 sval = (s64)operand->fn(operand, elt, rbe, event);
|
2018-01-16 11:51:52 +09:00
|
|
|
u64 val = (u64)-sval;
|
|
|
|
|
|
|
|
|
|
return val;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
#define DEFINE_HIST_FIELD_FN(type) \
|
2018-01-16 11:51:43 +09:00
|
|
|
static u64 hist_field_##type(struct hist_field *hist_field, \
|
2018-01-16 11:51:54 +09:00
|
|
|
struct tracing_map_elt *elt, \
|
|
|
|
|
struct ring_buffer_event *rbe, \
|
|
|
|
|
void *event) \
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
{ \
|
|
|
|
|
type *addr = (type *)(event + hist_field->field->offset); \
|
|
|
|
|
\
|
2016-03-04 03:54:53 +09:00
|
|
|
return (u64)(unsigned long)*addr; \
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
DEFINE_HIST_FIELD_FN(s64);
|
|
|
|
|
DEFINE_HIST_FIELD_FN(u64);
|
|
|
|
|
DEFINE_HIST_FIELD_FN(s32);
|
|
|
|
|
DEFINE_HIST_FIELD_FN(u32);
|
|
|
|
|
DEFINE_HIST_FIELD_FN(s16);
|
|
|
|
|
DEFINE_HIST_FIELD_FN(u16);
|
|
|
|
|
DEFINE_HIST_FIELD_FN(s8);
|
|
|
|
|
DEFINE_HIST_FIELD_FN(u8);
|
|
|
|
|
|
|
|
|
|
#define for_each_hist_field(i, hist_data) \
|
|
|
|
|
for ((i) = 0; (i) < (hist_data)->n_fields; (i)++)
|
|
|
|
|
|
|
|
|
|
#define for_each_hist_val_field(i, hist_data) \
|
|
|
|
|
for ((i) = 0; (i) < (hist_data)->n_vals; (i)++)
|
|
|
|
|
|
|
|
|
|
#define for_each_hist_key_field(i, hist_data) \
|
|
|
|
|
for ((i) = (hist_data)->n_vals; (i) < (hist_data)->n_fields; (i)++)
|
|
|
|
|
|
2016-03-04 03:54:52 +09:00
|
|
|
#define HIST_STACKTRACE_DEPTH 16
|
|
|
|
|
#define HIST_STACKTRACE_SIZE (HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
|
|
|
|
|
#define HIST_STACKTRACE_SKIP 5
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
#define HITCOUNT_IDX 0
|
2016-03-04 03:54:52 +09:00
|
|
|
#define HIST_KEY_SIZE_MAX (MAX_FILTER_STR_VAL + HIST_STACKTRACE_SIZE)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
|
|
|
|
enum hist_field_flags {
|
2017-09-23 04:58:21 +09:00
|
|
|
HIST_FIELD_FL_HITCOUNT = 1 << 0,
|
|
|
|
|
HIST_FIELD_FL_KEY = 1 << 1,
|
|
|
|
|
HIST_FIELD_FL_STRING = 1 << 2,
|
|
|
|
|
HIST_FIELD_FL_HEX = 1 << 3,
|
|
|
|
|
HIST_FIELD_FL_SYM = 1 << 4,
|
|
|
|
|
HIST_FIELD_FL_SYM_OFFSET = 1 << 5,
|
|
|
|
|
HIST_FIELD_FL_EXECNAME = 1 << 6,
|
|
|
|
|
HIST_FIELD_FL_SYSCALL = 1 << 7,
|
|
|
|
|
HIST_FIELD_FL_STACKTRACE = 1 << 8,
|
|
|
|
|
HIST_FIELD_FL_LOG2 = 1 << 9,
|
2018-01-16 11:51:45 +09:00
|
|
|
HIST_FIELD_FL_TIMESTAMP = 1 << 10,
|
2018-01-16 11:51:48 +09:00
|
|
|
HIST_FIELD_FL_TIMESTAMP_USECS = 1 << 11,
|
2018-01-16 11:51:49 +09:00
|
|
|
HIST_FIELD_FL_VAR = 1 << 12,
|
2018-01-16 11:51:52 +09:00
|
|
|
HIST_FIELD_FL_EXPR = 1 << 13,
|
2018-01-16 11:51:56 +09:00
|
|
|
HIST_FIELD_FL_VAR_REF = 1 << 14,
|
2018-01-16 11:52:03 +09:00
|
|
|
HIST_FIELD_FL_CPU = 1 << 15,
|
2018-01-16 11:52:04 +09:00
|
|
|
HIST_FIELD_FL_ALIAS = 1 << 16,
|
2018-01-16 11:51:49 +09:00
|
|
|
};
|
|
|
|
|
|
|
|
|
|
struct var_defs {
|
|
|
|
|
unsigned int n_vars;
|
|
|
|
|
char *name[TRACING_MAP_VARS_MAX];
|
|
|
|
|
char *expr[TRACING_MAP_VARS_MAX];
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
};
|
|
|
|
|
|
|
|
|
|
struct hist_trigger_attrs {
|
|
|
|
|
char *keys_str;
|
2016-03-04 03:54:43 +09:00
|
|
|
char *vals_str;
|
2016-03-04 03:54:45 +09:00
|
|
|
char *sort_key_str;
|
2016-03-04 03:54:59 +09:00
|
|
|
char *name;
|
2018-01-16 11:52:08 +09:00
|
|
|
char *clock;
|
2016-03-04 03:54:46 +09:00
|
|
|
bool pause;
|
|
|
|
|
bool cont;
|
2016-03-04 03:54:47 +09:00
|
|
|
bool clear;
|
2018-01-16 11:51:48 +09:00
|
|
|
bool ts_in_usecs;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
unsigned int map_bits;
|
2018-01-16 11:51:49 +09:00
|
|
|
|
|
|
|
|
char *assignment_str[TRACING_MAP_VARS_MAX];
|
|
|
|
|
unsigned int n_assignments;
|
|
|
|
|
|
2018-01-16 11:51:57 +09:00
|
|
|
char *action_str[HIST_ACTIONS_MAX];
|
|
|
|
|
unsigned int n_actions;
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
struct var_defs var_defs;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
};
|
|
|
|
|
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
struct field_var {
|
|
|
|
|
struct hist_field *var;
|
|
|
|
|
struct hist_field *val;
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
struct field_var_hist {
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
|
|
|
|
char *cmd;
|
|
|
|
|
};
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
struct hist_trigger_data {
|
2018-01-16 11:51:49 +09:00
|
|
|
struct hist_field *fields[HIST_FIELDS_MAX];
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
unsigned int n_vals;
|
|
|
|
|
unsigned int n_keys;
|
|
|
|
|
unsigned int n_fields;
|
2018-01-16 11:51:49 +09:00
|
|
|
unsigned int n_vars;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
unsigned int key_size;
|
|
|
|
|
struct tracing_map_sort_key sort_keys[TRACING_MAP_SORT_KEYS_MAX];
|
|
|
|
|
unsigned int n_sort_keys;
|
|
|
|
|
struct trace_event_file *event_file;
|
|
|
|
|
struct hist_trigger_attrs *attrs;
|
|
|
|
|
struct tracing_map *map;
|
2018-01-16 11:51:45 +09:00
|
|
|
bool enable_timestamps;
|
2018-01-16 11:51:49 +09:00
|
|
|
bool remove;
|
2018-01-16 11:51:56 +09:00
|
|
|
struct hist_field *var_refs[TRACING_MAP_VARS_MAX];
|
|
|
|
|
unsigned int n_var_refs;
|
2018-01-16 11:51:57 +09:00
|
|
|
|
|
|
|
|
struct action_data *actions[HIST_ACTIONS_MAX];
|
|
|
|
|
unsigned int n_actions;
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
|
|
|
|
|
struct field_var *field_vars[SYNTH_FIELDS_MAX];
|
|
|
|
|
unsigned int n_field_vars;
|
|
|
|
|
unsigned int n_field_var_str;
|
|
|
|
|
struct field_var_hist *field_var_hists[SYNTH_FIELDS_MAX];
|
|
|
|
|
unsigned int n_field_var_hists;
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
struct field_var *save_vars[SYNTH_FIELDS_MAX];
|
|
|
|
|
unsigned int n_save_vars;
|
|
|
|
|
unsigned int n_save_var_str;
|
2018-01-16 11:51:57 +09:00
|
|
|
};
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
static int synth_event_create(int argc, const char **argv);
|
|
|
|
|
static int synth_event_show(struct seq_file *m, struct dyn_event *ev);
|
|
|
|
|
static int synth_event_release(struct dyn_event *ev);
|
|
|
|
|
static bool synth_event_is_busy(struct dyn_event *ev);
|
|
|
|
|
static bool synth_event_match(const char *system, const char *event,
|
2019-06-20 00:07:39 +09:00
|
|
|
int argc, const char **argv, struct dyn_event *ev);
|
2018-11-05 18:03:33 +09:00
|
|
|
|
|
|
|
|
static struct dyn_event_operations synth_event_ops = {
|
|
|
|
|
.create = synth_event_create,
|
|
|
|
|
.show = synth_event_show,
|
|
|
|
|
.is_busy = synth_event_is_busy,
|
|
|
|
|
.free = synth_event_release,
|
|
|
|
|
.match = synth_event_match,
|
|
|
|
|
};
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
struct synth_field {
|
|
|
|
|
char *type;
|
|
|
|
|
char *name;
|
|
|
|
|
size_t size;
|
|
|
|
|
bool is_signed;
|
|
|
|
|
bool is_string;
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
struct synth_event {
|
2018-11-05 18:03:33 +09:00
|
|
|
struct dyn_event devent;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
int ref;
|
|
|
|
|
char *name;
|
|
|
|
|
struct synth_field **fields;
|
|
|
|
|
unsigned int n_fields;
|
|
|
|
|
unsigned int n_u64;
|
|
|
|
|
struct trace_event_class class;
|
|
|
|
|
struct trace_event_call call;
|
|
|
|
|
struct tracepoint *tp;
|
|
|
|
|
};
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
static bool is_synth_event(struct dyn_event *ev)
|
|
|
|
|
{
|
|
|
|
|
return ev->ops == &synth_event_ops;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct synth_event *to_synth_event(struct dyn_event *ev)
|
|
|
|
|
{
|
|
|
|
|
return container_of(ev, struct synth_event, devent);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool synth_event_is_busy(struct dyn_event *ev)
|
|
|
|
|
{
|
|
|
|
|
struct synth_event *event = to_synth_event(ev);
|
|
|
|
|
|
|
|
|
|
return event->ref != 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool synth_event_match(const char *system, const char *event,
|
2019-06-20 00:07:39 +09:00
|
|
|
int argc, const char **argv, struct dyn_event *ev)
|
2018-11-05 18:03:33 +09:00
|
|
|
{
|
|
|
|
|
struct synth_event *sev = to_synth_event(ev);
|
|
|
|
|
|
|
|
|
|
return strcmp(sev->name, event) == 0 &&
|
|
|
|
|
(!system || strcmp(system, SYNTH_SYSTEM) == 0);
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:57 +09:00
|
|
|
struct action_data;
|
|
|
|
|
|
|
|
|
|
typedef void (*action_fn_t) (struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt, void *rec,
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
struct ring_buffer_event *rbe, void *key,
|
2018-01-16 11:51:57 +09:00
|
|
|
struct action_data *data, u64 *var_ref_vals);
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
typedef bool (*check_track_val_fn_t) (u64 track_val, u64 var_val);
|
|
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
enum handler_id {
|
|
|
|
|
HANDLER_ONMATCH = 1,
|
|
|
|
|
HANDLER_ONMAX,
|
2019-02-14 08:42:48 +09:00
|
|
|
HANDLER_ONCHANGE,
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
};
|
|
|
|
|
|
|
|
|
|
enum action_id {
|
|
|
|
|
ACTION_SAVE = 1,
|
|
|
|
|
ACTION_TRACE,
|
2019-02-14 08:42:46 +09:00
|
|
|
ACTION_SNAPSHOT,
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
};
|
|
|
|
|
|
2018-01-16 11:51:57 +09:00
|
|
|
struct action_data {
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
enum handler_id handler;
|
|
|
|
|
enum action_id action;
|
|
|
|
|
char *action_name;
|
2018-01-16 11:51:57 +09:00
|
|
|
action_fn_t fn;
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
|
2018-01-16 11:52:00 +09:00
|
|
|
unsigned int n_params;
|
|
|
|
|
char *params[SYNTH_FIELDS_MAX];
|
|
|
|
|
|
2019-02-14 08:42:43 +09:00
|
|
|
/*
|
|
|
|
|
* When a histogram trigger is hit, the values of any
|
|
|
|
|
* references to variables, including variables being passed
|
|
|
|
|
* as parameters to synthetic events, are collected into a
|
2020-01-30 11:18:18 +09:00
|
|
|
* var_ref_vals array. This var_ref_idx array is an array of
|
|
|
|
|
* indices into the var_ref_vals array, one for each synthetic
|
|
|
|
|
* event param, and is passed to the synthetic event
|
|
|
|
|
* invocation.
|
2019-02-14 08:42:43 +09:00
|
|
|
*/
|
2020-01-30 11:18:18 +09:00
|
|
|
unsigned int var_ref_idx[TRACING_MAP_VARS_MAX];
|
2019-02-14 08:42:43 +09:00
|
|
|
struct synth_event *synth_event;
|
2019-02-14 08:42:50 +09:00
|
|
|
bool use_trace_keyword;
|
|
|
|
|
char *synth_event_name;
|
2019-02-14 08:42:43 +09:00
|
|
|
|
2018-01-16 11:52:00 +09:00
|
|
|
union {
|
|
|
|
|
struct {
|
2019-02-14 08:42:43 +09:00
|
|
|
char *event;
|
|
|
|
|
char *event_system;
|
|
|
|
|
} match_data;
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
|
|
|
|
|
struct {
|
2019-02-14 08:42:44 +09:00
|
|
|
/*
|
|
|
|
|
* var_str contains the $-unstripped variable
|
|
|
|
|
* name referenced by var_ref, and used when
|
|
|
|
|
* printing the action. Because var_ref
|
|
|
|
|
* creation is deferred to create_actions(),
|
|
|
|
|
* we need a per-action way to save it until
|
|
|
|
|
* then, thus var_str.
|
|
|
|
|
*/
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
char *var_str;
|
2019-02-14 08:42:44 +09:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* var_ref refers to the variable being
|
|
|
|
|
* tracked e.g onmax($var).
|
|
|
|
|
*/
|
|
|
|
|
struct hist_field *var_ref;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* track_var contains the 'invisible' tracking
|
|
|
|
|
* variable created to keep the current
|
|
|
|
|
* e.g. max value.
|
|
|
|
|
*/
|
|
|
|
|
struct hist_field *track_var;
|
|
|
|
|
|
|
|
|
|
check_track_val_fn_t check_val;
|
|
|
|
|
action_fn_t save_data;
|
|
|
|
|
} track_data;
|
2018-01-16 11:52:00 +09:00
|
|
|
};
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
};
|
|
|
|
|
|
2019-02-14 08:42:46 +09:00
|
|
|
struct track_data {
|
|
|
|
|
u64 track_val;
|
|
|
|
|
bool updated;
|
|
|
|
|
|
|
|
|
|
unsigned int key_len;
|
|
|
|
|
void *key;
|
|
|
|
|
struct tracing_map_elt elt;
|
|
|
|
|
|
|
|
|
|
struct action_data *action_data;
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
struct hist_elt_data {
|
|
|
|
|
char *comm;
|
|
|
|
|
u64 *var_ref_vals;
|
|
|
|
|
char *field_var_str[SYNTH_FIELDS_MAX];
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
struct snapshot_context {
|
|
|
|
|
struct tracing_map_elt *elt;
|
|
|
|
|
void *key;
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static void track_data_free(struct track_data *track_data)
|
|
|
|
|
{
|
|
|
|
|
struct hist_elt_data *elt_data;
|
|
|
|
|
|
|
|
|
|
if (!track_data)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
kfree(track_data->key);
|
|
|
|
|
|
|
|
|
|
elt_data = track_data->elt.private_data;
|
|
|
|
|
if (elt_data) {
|
|
|
|
|
kfree(elt_data->comm);
|
|
|
|
|
kfree(elt_data);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
kfree(track_data);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct track_data *track_data_alloc(unsigned int key_len,
|
|
|
|
|
struct action_data *action_data,
|
|
|
|
|
struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct track_data *data = kzalloc(sizeof(*data), GFP_KERNEL);
|
|
|
|
|
struct hist_elt_data *elt_data;
|
|
|
|
|
|
|
|
|
|
if (!data)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
data->key = kzalloc(key_len, GFP_KERNEL);
|
|
|
|
|
if (!data->key) {
|
|
|
|
|
track_data_free(data);
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
data->key_len = key_len;
|
|
|
|
|
data->action_data = action_data;
|
|
|
|
|
data->hist_data = hist_data;
|
|
|
|
|
|
|
|
|
|
elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL);
|
|
|
|
|
if (!elt_data) {
|
|
|
|
|
track_data_free(data);
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
}
|
|
|
|
|
data->elt.private_data = elt_data;
|
|
|
|
|
|
|
|
|
|
elt_data->comm = kzalloc(TASK_COMM_LEN, GFP_KERNEL);
|
|
|
|
|
if (!elt_data->comm) {
|
|
|
|
|
track_data_free(data);
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return data;
|
|
|
|
|
}
|
|
|
|
|
|
2019-04-01 08:48:16 +09:00
|
|
|
static char last_cmd[MAX_FILTER_STR_VAL];
|
|
|
|
|
static char last_cmd_loc[MAX_FILTER_STR_VAL];
|
2018-01-16 11:52:05 +09:00
|
|
|
|
2019-04-01 08:48:17 +09:00
|
|
|
static int errpos(char *str)
|
2018-01-16 11:52:05 +09:00
|
|
|
{
|
2019-04-01 08:48:17 +09:00
|
|
|
return err_pos(last_cmd, str);
|
2018-01-16 11:52:05 +09:00
|
|
|
}
|
|
|
|
|
|
2019-04-01 08:48:16 +09:00
|
|
|
static void last_cmd_set(struct trace_event_file *file, char *str)
|
2018-01-16 11:52:05 +09:00
|
|
|
{
|
2019-04-01 08:48:16 +09:00
|
|
|
const char *system = NULL, *name = NULL;
|
|
|
|
|
struct trace_event_call *call;
|
2018-01-16 11:52:05 +09:00
|
|
|
|
|
|
|
|
if (!str)
|
|
|
|
|
return;
|
|
|
|
|
|
2019-04-01 08:48:16 +09:00
|
|
|
strncpy(last_cmd, str, MAX_FILTER_STR_VAL - 1);
|
2018-01-16 11:52:05 +09:00
|
|
|
|
2019-04-01 08:48:16 +09:00
|
|
|
if (file) {
|
|
|
|
|
call = file->event_call;
|
2018-01-16 11:52:05 +09:00
|
|
|
|
2019-04-01 08:48:16 +09:00
|
|
|
system = call->class->system;
|
|
|
|
|
if (system) {
|
|
|
|
|
name = trace_event_name(call);
|
|
|
|
|
if (!name)
|
|
|
|
|
system = NULL;
|
|
|
|
|
}
|
|
|
|
|
}
|
2018-01-16 11:52:05 +09:00
|
|
|
|
2019-04-01 08:48:16 +09:00
|
|
|
if (system)
|
|
|
|
|
snprintf(last_cmd_loc, MAX_FILTER_STR_VAL, "hist:%s:%s", system, name);
|
2018-01-16 11:52:05 +09:00
|
|
|
}
|
|
|
|
|
|
2019-04-02 11:30:22 +09:00
|
|
|
static void hist_err(struct trace_array *tr, u8 err_type, u8 err_pos)
|
2018-01-16 11:52:05 +09:00
|
|
|
{
|
2019-04-02 11:52:21 +09:00
|
|
|
tracing_log_err(tr, last_cmd_loc, last_cmd, err_text,
|
|
|
|
|
err_type, err_pos);
|
2018-01-16 11:52:05 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void hist_err_clear(void)
|
|
|
|
|
{
|
2019-04-01 08:48:16 +09:00
|
|
|
last_cmd[0] = '\0';
|
|
|
|
|
last_cmd_loc[0] = '\0';
|
2018-01-16 11:52:05 +09:00
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
struct synth_trace_event {
|
|
|
|
|
struct trace_entry ent;
|
|
|
|
|
u64 fields[];
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static int synth_event_define_fields(struct trace_event_call *call)
|
|
|
|
|
{
|
|
|
|
|
struct synth_trace_event trace;
|
|
|
|
|
int offset = offsetof(typeof(trace), fields);
|
|
|
|
|
struct synth_event *event = call->data;
|
|
|
|
|
unsigned int i, size, n_u64;
|
|
|
|
|
char *name, *type;
|
|
|
|
|
bool is_signed;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
|
|
|
|
|
size = event->fields[i]->size;
|
|
|
|
|
is_signed = event->fields[i]->is_signed;
|
|
|
|
|
type = event->fields[i]->type;
|
|
|
|
|
name = event->fields[i]->name;
|
|
|
|
|
ret = trace_define_field(call, type, name, offset, size,
|
|
|
|
|
is_signed, FILTER_OTHER);
|
|
|
|
|
if (ret)
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
|
|
if (event->fields[i]->is_string) {
|
|
|
|
|
offset += STR_VAR_LEN_MAX;
|
|
|
|
|
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
|
|
|
|
|
} else {
|
|
|
|
|
offset += sizeof(u64);
|
|
|
|
|
n_u64++;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
event->n_u64 = n_u64;
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool synth_field_signed(char *type)
|
|
|
|
|
{
|
2018-12-21 03:20:07 +09:00
|
|
|
if (str_has_prefix(type, "u"))
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
return false;
|
tracing: Fix "gfp_t" format for synthetic events
In the format of synthetic events, the "gfp_t" is shown as "signed:1",
but in fact the "gfp_t" is "unsigned", should be shown as "signed:0".
The issue can be reproduced by the following commands:
echo 'memlatency u64 lat; unsigned int order; gfp_t gfp_flags; int migratetype' > /sys/kernel/debug/tracing/synthetic_events
cat /sys/kernel/debug/tracing/events/synthetic/memlatency/format
name: memlatency
ID: 2233
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
field:unsigned char common_flags; offset:2; size:1; signed:0;
field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:u64 lat; offset:8; size:8; signed:0;
field:unsigned int order; offset:16; size:4; signed:0;
field:gfp_t gfp_flags; offset:24; size:4; signed:1;
field:int migratetype; offset:32; size:4; signed:1;
print fmt: "lat=%llu, order=%u, gfp_flags=%x, migratetype=%d", REC->lat, REC->order, REC->gfp_flags, REC->migratetype
Link: http://lkml.kernel.org/r/20191018012034.6404-1-zhengjun.xing@linux.intel.com
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Zhengjun Xing <zhengjun.xing@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-10-18 10:20:34 +09:00
|
|
|
if (strcmp(type, "gfp_t") == 0)
|
|
|
|
|
return false;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int synth_field_is_string(char *type)
|
|
|
|
|
{
|
|
|
|
|
if (strstr(type, "char[") != NULL)
|
|
|
|
|
return true;
|
|
|
|
|
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int synth_field_string_size(char *type)
|
|
|
|
|
{
|
|
|
|
|
char buf[4], *end, *start;
|
|
|
|
|
unsigned int len;
|
|
|
|
|
int size, err;
|
|
|
|
|
|
|
|
|
|
start = strstr(type, "char[");
|
|
|
|
|
if (start == NULL)
|
|
|
|
|
return -EINVAL;
|
2018-12-19 05:33:21 +09:00
|
|
|
start += sizeof("char[") - 1;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
|
|
|
|
|
end = strchr(type, ']');
|
|
|
|
|
if (!end || end < start)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
len = end - start;
|
|
|
|
|
if (len > 3)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
strncpy(buf, start, len);
|
|
|
|
|
buf[len] = '\0';
|
|
|
|
|
|
|
|
|
|
err = kstrtouint(buf, 0, &size);
|
|
|
|
|
if (err)
|
|
|
|
|
return err;
|
|
|
|
|
|
|
|
|
|
if (size > STR_VAR_LEN_MAX)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
return size;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int synth_field_size(char *type)
|
|
|
|
|
{
|
|
|
|
|
int size = 0;
|
|
|
|
|
|
|
|
|
|
if (strcmp(type, "s64") == 0)
|
|
|
|
|
size = sizeof(s64);
|
|
|
|
|
else if (strcmp(type, "u64") == 0)
|
|
|
|
|
size = sizeof(u64);
|
|
|
|
|
else if (strcmp(type, "s32") == 0)
|
|
|
|
|
size = sizeof(s32);
|
|
|
|
|
else if (strcmp(type, "u32") == 0)
|
|
|
|
|
size = sizeof(u32);
|
|
|
|
|
else if (strcmp(type, "s16") == 0)
|
|
|
|
|
size = sizeof(s16);
|
|
|
|
|
else if (strcmp(type, "u16") == 0)
|
|
|
|
|
size = sizeof(u16);
|
|
|
|
|
else if (strcmp(type, "s8") == 0)
|
|
|
|
|
size = sizeof(s8);
|
|
|
|
|
else if (strcmp(type, "u8") == 0)
|
|
|
|
|
size = sizeof(u8);
|
|
|
|
|
else if (strcmp(type, "char") == 0)
|
|
|
|
|
size = sizeof(char);
|
|
|
|
|
else if (strcmp(type, "unsigned char") == 0)
|
|
|
|
|
size = sizeof(unsigned char);
|
|
|
|
|
else if (strcmp(type, "int") == 0)
|
|
|
|
|
size = sizeof(int);
|
|
|
|
|
else if (strcmp(type, "unsigned int") == 0)
|
|
|
|
|
size = sizeof(unsigned int);
|
|
|
|
|
else if (strcmp(type, "long") == 0)
|
|
|
|
|
size = sizeof(long);
|
|
|
|
|
else if (strcmp(type, "unsigned long") == 0)
|
|
|
|
|
size = sizeof(unsigned long);
|
|
|
|
|
else if (strcmp(type, "pid_t") == 0)
|
|
|
|
|
size = sizeof(pid_t);
|
2019-07-12 10:53:08 +09:00
|
|
|
else if (strcmp(type, "gfp_t") == 0)
|
|
|
|
|
size = sizeof(gfp_t);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
else if (synth_field_is_string(type))
|
|
|
|
|
size = synth_field_string_size(type);
|
|
|
|
|
|
|
|
|
|
return size;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static const char *synth_field_fmt(char *type)
|
|
|
|
|
{
|
|
|
|
|
const char *fmt = "%llu";
|
|
|
|
|
|
|
|
|
|
if (strcmp(type, "s64") == 0)
|
|
|
|
|
fmt = "%lld";
|
|
|
|
|
else if (strcmp(type, "u64") == 0)
|
|
|
|
|
fmt = "%llu";
|
|
|
|
|
else if (strcmp(type, "s32") == 0)
|
|
|
|
|
fmt = "%d";
|
|
|
|
|
else if (strcmp(type, "u32") == 0)
|
|
|
|
|
fmt = "%u";
|
|
|
|
|
else if (strcmp(type, "s16") == 0)
|
|
|
|
|
fmt = "%d";
|
|
|
|
|
else if (strcmp(type, "u16") == 0)
|
|
|
|
|
fmt = "%u";
|
|
|
|
|
else if (strcmp(type, "s8") == 0)
|
|
|
|
|
fmt = "%d";
|
|
|
|
|
else if (strcmp(type, "u8") == 0)
|
|
|
|
|
fmt = "%u";
|
|
|
|
|
else if (strcmp(type, "char") == 0)
|
|
|
|
|
fmt = "%d";
|
|
|
|
|
else if (strcmp(type, "unsigned char") == 0)
|
|
|
|
|
fmt = "%u";
|
|
|
|
|
else if (strcmp(type, "int") == 0)
|
|
|
|
|
fmt = "%d";
|
|
|
|
|
else if (strcmp(type, "unsigned int") == 0)
|
|
|
|
|
fmt = "%u";
|
|
|
|
|
else if (strcmp(type, "long") == 0)
|
|
|
|
|
fmt = "%ld";
|
|
|
|
|
else if (strcmp(type, "unsigned long") == 0)
|
|
|
|
|
fmt = "%lu";
|
|
|
|
|
else if (strcmp(type, "pid_t") == 0)
|
|
|
|
|
fmt = "%d";
|
2019-07-12 10:53:08 +09:00
|
|
|
else if (strcmp(type, "gfp_t") == 0)
|
|
|
|
|
fmt = "%x";
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
else if (synth_field_is_string(type))
|
|
|
|
|
fmt = "%s";
|
|
|
|
|
|
|
|
|
|
return fmt;
|
|
|
|
|
}
|
|
|
|
|
|
2020-02-15 07:56:41 +09:00
|
|
|
static void print_synth_event_num_val(struct trace_seq *s,
|
|
|
|
|
char *print_fmt, char *name,
|
|
|
|
|
int size, u64 val, char *space)
|
|
|
|
|
{
|
|
|
|
|
switch (size) {
|
|
|
|
|
case 1:
|
|
|
|
|
trace_seq_printf(s, print_fmt, name, (u8)val, space);
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
|
|
case 2:
|
|
|
|
|
trace_seq_printf(s, print_fmt, name, (u16)val, space);
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
|
|
case 4:
|
|
|
|
|
trace_seq_printf(s, print_fmt, name, (u32)val, space);
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
|
|
default:
|
|
|
|
|
trace_seq_printf(s, print_fmt, name, val, space);
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
static enum print_line_t print_synth_event(struct trace_iterator *iter,
|
|
|
|
|
int flags,
|
|
|
|
|
struct trace_event *event)
|
|
|
|
|
{
|
|
|
|
|
struct trace_array *tr = iter->tr;
|
|
|
|
|
struct trace_seq *s = &iter->seq;
|
|
|
|
|
struct synth_trace_event *entry;
|
|
|
|
|
struct synth_event *se;
|
|
|
|
|
unsigned int i, n_u64;
|
|
|
|
|
char print_fmt[32];
|
|
|
|
|
const char *fmt;
|
|
|
|
|
|
|
|
|
|
entry = (struct synth_trace_event *)iter->ent;
|
|
|
|
|
se = container_of(event, struct synth_event, call.event);
|
|
|
|
|
|
|
|
|
|
trace_seq_printf(s, "%s: ", se->name);
|
|
|
|
|
|
|
|
|
|
for (i = 0, n_u64 = 0; i < se->n_fields; i++) {
|
|
|
|
|
if (trace_seq_has_overflowed(s))
|
|
|
|
|
goto end;
|
|
|
|
|
|
|
|
|
|
fmt = synth_field_fmt(se->fields[i]->type);
|
|
|
|
|
|
|
|
|
|
/* parameter types */
|
|
|
|
|
if (tr->trace_flags & TRACE_ITER_VERBOSE)
|
|
|
|
|
trace_seq_printf(s, "%s ", fmt);
|
|
|
|
|
|
|
|
|
|
snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt);
|
|
|
|
|
|
|
|
|
|
/* parameter values */
|
|
|
|
|
if (se->fields[i]->is_string) {
|
|
|
|
|
trace_seq_printf(s, print_fmt, se->fields[i]->name,
|
|
|
|
|
(char *)&entry->fields[n_u64],
|
|
|
|
|
i == se->n_fields - 1 ? "" : " ");
|
|
|
|
|
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
|
|
|
|
|
} else {
|
2019-07-12 10:53:08 +09:00
|
|
|
struct trace_print_flags __flags[] = {
|
|
|
|
|
__def_gfpflag_names, {-1, NULL} };
|
2020-02-15 07:56:41 +09:00
|
|
|
char *space = (i == se->n_fields - 1 ? "" : " ");
|
2019-07-12 10:53:08 +09:00
|
|
|
|
2020-02-15 07:56:41 +09:00
|
|
|
print_synth_event_num_val(s, print_fmt,
|
|
|
|
|
se->fields[i]->name,
|
|
|
|
|
se->fields[i]->size,
|
|
|
|
|
entry->fields[n_u64],
|
|
|
|
|
space);
|
2019-07-12 10:53:08 +09:00
|
|
|
|
|
|
|
|
if (strcmp(se->fields[i]->type, "gfp_t") == 0) {
|
|
|
|
|
trace_seq_puts(s, " (");
|
|
|
|
|
trace_print_flags_seq(s, "|",
|
|
|
|
|
entry->fields[n_u64],
|
|
|
|
|
__flags);
|
|
|
|
|
trace_seq_putc(s, ')');
|
|
|
|
|
}
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
n_u64++;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
end:
|
|
|
|
|
trace_seq_putc(s, '\n');
|
|
|
|
|
|
|
|
|
|
return trace_handle_return(s);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct trace_event_functions synth_event_funcs = {
|
|
|
|
|
.trace = print_synth_event
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static notrace void trace_event_raw_event_synth(void *__data,
|
|
|
|
|
u64 *var_ref_vals,
|
2020-01-30 11:18:18 +09:00
|
|
|
unsigned int *var_ref_idx)
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
{
|
|
|
|
|
struct trace_event_file *trace_file = __data;
|
|
|
|
|
struct synth_trace_event *entry;
|
|
|
|
|
struct trace_event_buffer fbuffer;
|
2018-02-08 07:29:46 +09:00
|
|
|
struct ring_buffer *buffer;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
struct synth_event *event;
|
2020-01-30 11:18:18 +09:00
|
|
|
unsigned int i, n_u64, val_idx;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
int fields_size = 0;
|
|
|
|
|
|
|
|
|
|
event = trace_file->event_call->data;
|
|
|
|
|
|
|
|
|
|
if (trace_trigger_soft_disabled(trace_file))
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
fields_size = event->n_u64 * sizeof(u64);
|
|
|
|
|
|
2018-02-08 07:29:46 +09:00
|
|
|
/*
|
|
|
|
|
* Avoid ring buffer recursion detection, as this event
|
|
|
|
|
* is being performed within another event.
|
|
|
|
|
*/
|
|
|
|
|
buffer = trace_file->tr->trace_buffer.buffer;
|
|
|
|
|
ring_buffer_nest_start(buffer);
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
entry = trace_event_buffer_reserve(&fbuffer, trace_file,
|
|
|
|
|
sizeof(*entry) + fields_size);
|
|
|
|
|
if (!entry)
|
2018-02-08 07:29:46 +09:00
|
|
|
goto out;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
|
|
|
|
|
for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
|
2020-01-30 11:18:18 +09:00
|
|
|
val_idx = var_ref_idx[i];
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
if (event->fields[i]->is_string) {
|
2020-01-30 11:18:18 +09:00
|
|
|
char *str_val = (char *)(long)var_ref_vals[val_idx];
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
char *str_field = (char *)&entry->fields[n_u64];
|
|
|
|
|
|
2018-03-29 05:10:56 +09:00
|
|
|
strscpy(str_field, str_val, STR_VAR_LEN_MAX);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
|
|
|
|
|
} else {
|
2019-12-18 16:44:27 +09:00
|
|
|
struct synth_field *field = event->fields[i];
|
2020-01-30 11:18:18 +09:00
|
|
|
u64 val = var_ref_vals[val_idx];
|
2019-12-18 16:44:27 +09:00
|
|
|
|
|
|
|
|
switch (field->size) {
|
|
|
|
|
case 1:
|
|
|
|
|
*(u8 *)&entry->fields[n_u64] = (u8)val;
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
|
|
case 2:
|
|
|
|
|
*(u16 *)&entry->fields[n_u64] = (u16)val;
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
|
|
case 4:
|
|
|
|
|
*(u32 *)&entry->fields[n_u64] = (u32)val;
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
|
|
default:
|
|
|
|
|
entry->fields[n_u64] = val;
|
|
|
|
|
break;
|
|
|
|
|
}
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
n_u64++;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
trace_event_buffer_commit(&fbuffer);
|
2018-02-08 07:29:46 +09:00
|
|
|
out:
|
|
|
|
|
ring_buffer_nest_end(buffer);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void free_synth_event_print_fmt(struct trace_event_call *call)
|
|
|
|
|
{
|
|
|
|
|
if (call) {
|
|
|
|
|
kfree(call->print_fmt);
|
|
|
|
|
call->print_fmt = NULL;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int __set_synth_event_print_fmt(struct synth_event *event,
|
|
|
|
|
char *buf, int len)
|
|
|
|
|
{
|
|
|
|
|
const char *fmt;
|
|
|
|
|
int pos = 0;
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
/* When len=0, we just calculate the needed length */
|
|
|
|
|
#define LEN_OR_ZERO (len ? len - pos : 0)
|
|
|
|
|
|
|
|
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
|
|
|
|
|
for (i = 0; i < event->n_fields; i++) {
|
|
|
|
|
fmt = synth_field_fmt(event->fields[i]->type);
|
|
|
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s%s",
|
|
|
|
|
event->fields[i]->name, fmt,
|
|
|
|
|
i == event->n_fields - 1 ? "" : ", ");
|
|
|
|
|
}
|
|
|
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < event->n_fields; i++) {
|
|
|
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO,
|
|
|
|
|
", REC->%s", event->fields[i]->name);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#undef LEN_OR_ZERO
|
|
|
|
|
|
|
|
|
|
/* return the length of print_fmt */
|
|
|
|
|
return pos;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int set_synth_event_print_fmt(struct trace_event_call *call)
|
|
|
|
|
{
|
|
|
|
|
struct synth_event *event = call->data;
|
|
|
|
|
char *print_fmt;
|
|
|
|
|
int len;
|
|
|
|
|
|
|
|
|
|
/* First: called with 0 length to calculate the needed length */
|
|
|
|
|
len = __set_synth_event_print_fmt(event, NULL, 0);
|
|
|
|
|
|
|
|
|
|
print_fmt = kmalloc(len + 1, GFP_KERNEL);
|
|
|
|
|
if (!print_fmt)
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
|
|
/* Second: actually write the @print_fmt */
|
|
|
|
|
__set_synth_event_print_fmt(event, print_fmt, len + 1);
|
|
|
|
|
call->print_fmt = print_fmt;
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void free_synth_field(struct synth_field *field)
|
|
|
|
|
{
|
|
|
|
|
kfree(field->type);
|
|
|
|
|
kfree(field->name);
|
|
|
|
|
kfree(field);
|
|
|
|
|
}
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
static struct synth_field *parse_synth_field(int argc, const char **argv,
|
2018-10-18 22:12:05 +09:00
|
|
|
int *consumed)
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
{
|
|
|
|
|
struct synth_field *field;
|
2018-11-05 18:03:33 +09:00
|
|
|
const char *prefix = NULL, *field_type = argv[0], *field_name, *array;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
int len, ret = 0;
|
|
|
|
|
|
|
|
|
|
if (field_type[0] == ';')
|
|
|
|
|
field_type++;
|
|
|
|
|
|
2018-10-18 22:12:05 +09:00
|
|
|
if (!strcmp(field_type, "unsigned")) {
|
|
|
|
|
if (argc < 3)
|
|
|
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
|
prefix = "unsigned ";
|
|
|
|
|
field_type = argv[1];
|
|
|
|
|
field_name = argv[2];
|
|
|
|
|
*consumed = 3;
|
|
|
|
|
} else {
|
|
|
|
|
field_name = argv[1];
|
|
|
|
|
*consumed = 2;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
field = kzalloc(sizeof(*field), GFP_KERNEL);
|
|
|
|
|
if (!field)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
len = strlen(field_name);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
array = strchr(field_name, '[');
|
2018-11-05 18:03:33 +09:00
|
|
|
if (array)
|
|
|
|
|
len -= strlen(array);
|
|
|
|
|
else if (field_name[len - 1] == ';')
|
|
|
|
|
len--;
|
|
|
|
|
|
|
|
|
|
field->name = kmemdup_nul(field_name, len, GFP_KERNEL);
|
|
|
|
|
if (!field->name) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (field_type[0] == ';')
|
|
|
|
|
field_type++;
|
|
|
|
|
len = strlen(field_type) + 1;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
if (array)
|
|
|
|
|
len += strlen(array);
|
2018-10-18 22:12:05 +09:00
|
|
|
if (prefix)
|
|
|
|
|
len += strlen(prefix);
|
2018-11-05 18:03:33 +09:00
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
field->type = kzalloc(len, GFP_KERNEL);
|
|
|
|
|
if (!field->type) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
2018-10-18 22:12:05 +09:00
|
|
|
if (prefix)
|
|
|
|
|
strcat(field->type, prefix);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
strcat(field->type, field_type);
|
|
|
|
|
if (array) {
|
|
|
|
|
strcat(field->type, array);
|
2018-11-05 18:03:33 +09:00
|
|
|
if (field->type[len - 1] == ';')
|
|
|
|
|
field->type[len - 1] = '\0';
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
field->size = synth_field_size(field->type);
|
|
|
|
|
if (!field->size) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (synth_field_is_string(field->type))
|
|
|
|
|
field->is_string = true;
|
|
|
|
|
|
|
|
|
|
field->is_signed = synth_field_signed(field->type);
|
|
|
|
|
|
|
|
|
|
out:
|
|
|
|
|
return field;
|
|
|
|
|
free:
|
|
|
|
|
free_synth_field(field);
|
|
|
|
|
field = ERR_PTR(ret);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void free_synth_tracepoint(struct tracepoint *tp)
|
|
|
|
|
{
|
|
|
|
|
if (!tp)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
kfree(tp->name);
|
|
|
|
|
kfree(tp);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct tracepoint *alloc_synth_tracepoint(char *name)
|
|
|
|
|
{
|
|
|
|
|
struct tracepoint *tp;
|
|
|
|
|
|
|
|
|
|
tp = kzalloc(sizeof(*tp), GFP_KERNEL);
|
|
|
|
|
if (!tp)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
tp->name = kstrdup(name, GFP_KERNEL);
|
|
|
|
|
if (!tp->name) {
|
|
|
|
|
kfree(tp);
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return tp;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
typedef void (*synth_probe_func_t) (void *__data, u64 *var_ref_vals,
|
2020-01-30 11:18:18 +09:00
|
|
|
unsigned int *var_ref_idx);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
|
|
|
|
|
static inline void trace_synth(struct synth_event *event, u64 *var_ref_vals,
|
2020-01-30 11:18:18 +09:00
|
|
|
unsigned int *var_ref_idx)
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
{
|
|
|
|
|
struct tracepoint *tp = event->tp;
|
|
|
|
|
|
|
|
|
|
if (unlikely(atomic_read(&tp->key.enabled) > 0)) {
|
|
|
|
|
struct tracepoint_func *probe_func_ptr;
|
|
|
|
|
synth_probe_func_t probe_func;
|
|
|
|
|
void *__data;
|
|
|
|
|
|
|
|
|
|
if (!(cpu_online(raw_smp_processor_id())))
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
probe_func_ptr = rcu_dereference_sched((tp)->funcs);
|
|
|
|
|
if (probe_func_ptr) {
|
|
|
|
|
do {
|
|
|
|
|
probe_func = probe_func_ptr->func;
|
|
|
|
|
__data = probe_func_ptr->data;
|
|
|
|
|
probe_func(__data, var_ref_vals, var_ref_idx);
|
|
|
|
|
} while ((++probe_func_ptr)->func);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct synth_event *find_synth_event(const char *name)
|
|
|
|
|
{
|
2018-11-05 18:03:33 +09:00
|
|
|
struct dyn_event *pos;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
struct synth_event *event;
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
for_each_dyn_event(pos) {
|
|
|
|
|
if (!is_synth_event(pos))
|
|
|
|
|
continue;
|
|
|
|
|
event = to_synth_event(pos);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
if (strcmp(event->name, name) == 0)
|
|
|
|
|
return event;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int register_synth_event(struct synth_event *event)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_call *call = &event->call;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
event->call.class = &event->class;
|
|
|
|
|
event->class.system = kstrdup(SYNTH_SYSTEM, GFP_KERNEL);
|
|
|
|
|
if (!event->class.system) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
event->tp = alloc_synth_tracepoint(event->name);
|
|
|
|
|
if (IS_ERR(event->tp)) {
|
|
|
|
|
ret = PTR_ERR(event->tp);
|
|
|
|
|
event->tp = NULL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
INIT_LIST_HEAD(&call->class->fields);
|
|
|
|
|
call->event.funcs = &synth_event_funcs;
|
|
|
|
|
call->class->define_fields = synth_event_define_fields;
|
|
|
|
|
|
|
|
|
|
ret = register_trace_event(&call->event);
|
|
|
|
|
if (!ret) {
|
|
|
|
|
ret = -ENODEV;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
call->flags = TRACE_EVENT_FL_TRACEPOINT;
|
|
|
|
|
call->class->reg = trace_event_reg;
|
|
|
|
|
call->class->probe = trace_event_raw_event_synth;
|
|
|
|
|
call->data = event;
|
|
|
|
|
call->tp = event->tp;
|
|
|
|
|
|
2018-12-05 03:35:45 +09:00
|
|
|
ret = trace_add_event_call(call);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
if (ret) {
|
|
|
|
|
pr_warn("Failed to register synthetic event: %s\n",
|
|
|
|
|
trace_event_name(call));
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
ret = set_synth_event_print_fmt(call);
|
|
|
|
|
if (ret < 0) {
|
2018-12-05 03:35:45 +09:00
|
|
|
trace_remove_event_call(call);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
err:
|
|
|
|
|
unregister_trace_event(&call->event);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int unregister_synth_event(struct synth_event *event)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_call *call = &event->call;
|
|
|
|
|
int ret;
|
|
|
|
|
|
2018-12-05 03:35:45 +09:00
|
|
|
ret = trace_remove_event_call(call);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void free_synth_event(struct synth_event *event)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
if (!event)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < event->n_fields; i++)
|
|
|
|
|
free_synth_field(event->fields[i]);
|
|
|
|
|
|
|
|
|
|
kfree(event->fields);
|
|
|
|
|
kfree(event->name);
|
|
|
|
|
kfree(event->class.system);
|
|
|
|
|
free_synth_tracepoint(event->tp);
|
|
|
|
|
free_synth_event_print_fmt(&event->call);
|
|
|
|
|
kfree(event);
|
|
|
|
|
}
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
static struct synth_event *alloc_synth_event(const char *name, int n_fields,
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
struct synth_field **fields)
|
|
|
|
|
{
|
|
|
|
|
struct synth_event *event;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
event = kzalloc(sizeof(*event), GFP_KERNEL);
|
|
|
|
|
if (!event) {
|
|
|
|
|
event = ERR_PTR(-ENOMEM);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
event->name = kstrdup(name, GFP_KERNEL);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
if (!event->name) {
|
|
|
|
|
kfree(event);
|
|
|
|
|
event = ERR_PTR(-ENOMEM);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
event->fields = kcalloc(n_fields, sizeof(*event->fields), GFP_KERNEL);
|
|
|
|
|
if (!event->fields) {
|
|
|
|
|
free_synth_event(event);
|
|
|
|
|
event = ERR_PTR(-ENOMEM);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
dyn_event_init(&event->devent, &synth_event_ops);
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
for (i = 0; i < n_fields; i++)
|
|
|
|
|
event->fields[i] = fields[i];
|
|
|
|
|
|
|
|
|
|
event->n_fields = n_fields;
|
|
|
|
|
out:
|
|
|
|
|
return event;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:52:00 +09:00
|
|
|
static void action_trace(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt, void *rec,
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
struct ring_buffer_event *rbe, void *key,
|
2018-01-16 11:52:00 +09:00
|
|
|
struct action_data *data, u64 *var_ref_vals)
|
|
|
|
|
{
|
2019-02-14 08:42:43 +09:00
|
|
|
struct synth_event *event = data->synth_event;
|
2018-01-16 11:52:00 +09:00
|
|
|
|
2019-02-14 08:42:43 +09:00
|
|
|
trace_synth(event, var_ref_vals, data->var_ref_idx);
|
2018-01-16 11:52:00 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
struct hist_var_data {
|
|
|
|
|
struct list_head list;
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
|
|
|
|
};
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
static int __create_synth_event(int argc, const char *name, const char **argv)
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
{
|
|
|
|
|
struct synth_field *field, *fields[SYNTH_FIELDS_MAX];
|
|
|
|
|
struct synth_event *event = NULL;
|
2018-10-18 22:12:05 +09:00
|
|
|
int i, consumed = 0, n_fields = 0, ret = 0;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Argument syntax:
|
|
|
|
|
* - Add synthetic event: <event_name> field[;field] ...
|
|
|
|
|
* - Remove synthetic event: !<event_name> field[;field] ...
|
|
|
|
|
* where 'field' = type field_name
|
|
|
|
|
*/
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
if (name[0] == '\0' || argc < 1)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
mutex_lock(&event_mutex);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
|
|
|
|
|
event = find_synth_event(name);
|
|
|
|
|
if (event) {
|
2018-11-05 18:03:33 +09:00
|
|
|
ret = -EEXIST;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
goto out;
|
2018-10-22 00:08:20 +09:00
|
|
|
}
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
for (i = 0; i < argc - 1; i++) {
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
if (strcmp(argv[i], ";") == 0)
|
|
|
|
|
continue;
|
|
|
|
|
if (n_fields == SYNTH_FIELDS_MAX) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
2018-10-18 22:12:05 +09:00
|
|
|
field = parse_synth_field(argc - i, &argv[i], &consumed);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
if (IS_ERR(field)) {
|
|
|
|
|
ret = PTR_ERR(field);
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
2018-10-18 22:12:05 +09:00
|
|
|
fields[n_fields++] = field;
|
|
|
|
|
i += consumed - 1;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
}
|
|
|
|
|
|
2018-10-18 22:12:34 +09:00
|
|
|
if (i < argc && strcmp(argv[i], ";") != 0) {
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
event = alloc_synth_event(name, n_fields, fields);
|
|
|
|
|
if (IS_ERR(event)) {
|
|
|
|
|
ret = PTR_ERR(event);
|
|
|
|
|
event = NULL;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
2018-11-05 18:01:12 +09:00
|
|
|
ret = register_synth_event(event);
|
|
|
|
|
if (!ret)
|
2018-11-05 18:03:33 +09:00
|
|
|
dyn_event_add(&event->devent);
|
2018-11-05 18:01:12 +09:00
|
|
|
else
|
|
|
|
|
free_synth_event(event);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
out:
|
tracing: Lock event_mutex before synth_event_mutex
synthetic event is using synth_event_mutex for protecting
synth_event_list, and event_trigger_write() path acquires
locks as below order.
event_trigger_write(event_mutex)
->trigger_process_regex(trigger_cmd_mutex)
->event_hist_trigger_func(synth_event_mutex)
On the other hand, synthetic event creation and deletion paths
call trace_add_event_call() and trace_remove_event_call()
which acquires event_mutex. In that case, if we keep the
synth_event_mutex locked while registering/unregistering synthetic
events, its dependency will be inversed.
To avoid this issue, current synthetic event is using a 2 phase
process to create/delete events. For example, it searches existing
events under synth_event_mutex to check for event-name conflicts, and
unlocks synth_event_mutex, then registers a new event under event_mutex
locked. Finally, it locks synth_event_mutex and tries to add the
new event to the list. But it can introduce complexity and a chance
for name conflicts.
To solve this simpler, this introduces trace_add_event_call_nolock()
and trace_remove_event_call_nolock() which don't acquire
event_mutex inside. synthetic event can lock event_mutex before
synth_event_mutex to solve the lock dependency issue simpler.
Link: http://lkml.kernel.org/r/154140844377.17322.13781091165954002713.stgit@devbox
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-05 18:00:43 +09:00
|
|
|
mutex_unlock(&event_mutex);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
err:
|
|
|
|
|
for (i = 0; i < n_fields; i++)
|
|
|
|
|
free_synth_field(fields[i]);
|
|
|
|
|
|
2018-11-05 18:01:12 +09:00
|
|
|
goto out;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
}
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
static int create_or_delete_synth_event(int argc, char **argv)
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
{
|
2018-11-05 18:03:33 +09:00
|
|
|
const char *name = argv[0];
|
|
|
|
|
struct synth_event *event = NULL;
|
|
|
|
|
int ret;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
/* trace_run_command() ensures argc != 0 */
|
|
|
|
|
if (name[0] == '!') {
|
|
|
|
|
mutex_lock(&event_mutex);
|
|
|
|
|
event = find_synth_event(name + 1);
|
|
|
|
|
if (event) {
|
|
|
|
|
if (event->ref)
|
|
|
|
|
ret = -EBUSY;
|
|
|
|
|
else {
|
|
|
|
|
ret = unregister_synth_event(event);
|
|
|
|
|
if (!ret) {
|
|
|
|
|
dyn_event_remove(&event->devent);
|
|
|
|
|
free_synth_event(event);
|
|
|
|
|
}
|
|
|
|
|
}
|
2018-11-05 18:01:12 +09:00
|
|
|
} else
|
2018-11-05 18:03:33 +09:00
|
|
|
ret = -ENOENT;
|
|
|
|
|
mutex_unlock(&event_mutex);
|
|
|
|
|
return ret;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
}
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
ret = __create_synth_event(argc - 1, name, (const char **)argv + 1);
|
|
|
|
|
return ret == -ECANCELED ? -EINVAL : ret;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
}
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
static int synth_event_create(int argc, const char **argv)
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
{
|
2018-11-05 18:03:33 +09:00
|
|
|
const char *name = argv[0];
|
|
|
|
|
int len;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
if (name[0] != 's' || name[1] != ':')
|
|
|
|
|
return -ECANCELED;
|
|
|
|
|
name += 2;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
/* This interface accepts group name prefix */
|
|
|
|
|
if (strchr(name, '/')) {
|
2019-02-05 06:07:23 +09:00
|
|
|
len = str_has_prefix(name, SYNTH_SYSTEM "/");
|
|
|
|
|
if (len == 0)
|
2018-11-05 18:03:33 +09:00
|
|
|
return -EINVAL;
|
|
|
|
|
name += len;
|
|
|
|
|
}
|
|
|
|
|
return __create_synth_event(argc - 1, name, argv + 1);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
}
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
static int synth_event_release(struct dyn_event *ev)
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
{
|
2018-11-05 18:03:33 +09:00
|
|
|
struct synth_event *event = to_synth_event(ev);
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
if (event->ref)
|
|
|
|
|
return -EBUSY;
|
|
|
|
|
|
|
|
|
|
ret = unregister_synth_event(event);
|
|
|
|
|
if (ret)
|
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
|
|
dyn_event_remove(ev);
|
|
|
|
|
free_synth_event(event);
|
|
|
|
|
return 0;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
}
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
static int __synth_event_show(struct seq_file *m, struct synth_event *event)
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
{
|
|
|
|
|
struct synth_field *field;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
seq_printf(m, "%s\t", event->name);
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < event->n_fields; i++) {
|
|
|
|
|
field = event->fields[i];
|
|
|
|
|
|
|
|
|
|
/* parameter values */
|
|
|
|
|
seq_printf(m, "%s %s%s", field->type, field->name,
|
|
|
|
|
i == event->n_fields - 1 ? "" : "; ");
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
seq_putc(m, '\n');
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
static int synth_event_show(struct seq_file *m, struct dyn_event *ev)
|
|
|
|
|
{
|
|
|
|
|
struct synth_event *event = to_synth_event(ev);
|
|
|
|
|
|
|
|
|
|
seq_printf(m, "s:%s/", event->class.system);
|
|
|
|
|
|
|
|
|
|
return __synth_event_show(m, event);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int synth_events_seq_show(struct seq_file *m, void *v)
|
|
|
|
|
{
|
|
|
|
|
struct dyn_event *ev = v;
|
|
|
|
|
|
|
|
|
|
if (!is_synth_event(ev))
|
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
|
|
return __synth_event_show(m, to_synth_event(ev));
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
static const struct seq_operations synth_events_seq_op = {
|
2018-11-05 18:03:33 +09:00
|
|
|
.start = dyn_event_seq_start,
|
|
|
|
|
.next = dyn_event_seq_next,
|
|
|
|
|
.stop = dyn_event_seq_stop,
|
|
|
|
|
.show = synth_events_seq_show,
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static int synth_events_open(struct inode *inode, struct file *file)
|
|
|
|
|
{
|
|
|
|
|
int ret;
|
|
|
|
|
|
2019-10-12 06:22:50 +09:00
|
|
|
ret = security_locked_down(LOCKDOWN_TRACEFS);
|
|
|
|
|
if (ret)
|
|
|
|
|
return ret;
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
|
2018-11-05 18:03:33 +09:00
|
|
|
ret = dyn_events_release_all(&synth_event_ops);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
if (ret < 0)
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return seq_open(file, &synth_events_seq_op);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static ssize_t synth_events_write(struct file *file,
|
|
|
|
|
const char __user *buffer,
|
|
|
|
|
size_t count, loff_t *ppos)
|
|
|
|
|
{
|
|
|
|
|
return trace_parse_run_command(file, buffer, count, ppos,
|
2018-11-05 18:03:33 +09:00
|
|
|
create_or_delete_synth_event);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static const struct file_operations synth_events_fops = {
|
|
|
|
|
.open = synth_events_open,
|
|
|
|
|
.write = synth_events_write,
|
|
|
|
|
.read = seq_read,
|
|
|
|
|
.llseek = seq_lseek,
|
|
|
|
|
.release = seq_release,
|
|
|
|
|
};
|
|
|
|
|
|
2018-01-16 11:51:54 +09:00
|
|
|
static u64 hist_field_timestamp(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
2018-01-16 11:51:48 +09:00
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = hist_field->hist_data;
|
|
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
|
|
|
|
|
|
|
|
|
u64 ts = ring_buffer_event_time_stamp(rbe);
|
|
|
|
|
|
|
|
|
|
if (hist_data->attrs->ts_in_usecs && trace_clock_in_ns(tr))
|
|
|
|
|
ts = ns2usecs(ts);
|
|
|
|
|
|
|
|
|
|
return ts;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:52:03 +09:00
|
|
|
static u64 hist_field_cpu(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
|
|
|
|
{
|
|
|
|
|
int cpu = smp_processor_id();
|
|
|
|
|
|
|
|
|
|
return cpu;
|
|
|
|
|
}
|
|
|
|
|
|
2018-12-19 05:33:23 +09:00
|
|
|
/**
|
|
|
|
|
* check_field_for_var_ref - Check if a VAR_REF field references a variable
|
|
|
|
|
* @hist_field: The VAR_REF field to check
|
|
|
|
|
* @var_data: The hist trigger that owns the variable
|
|
|
|
|
* @var_idx: The trigger variable identifier
|
|
|
|
|
*
|
|
|
|
|
* Check the given VAR_REF field to see whether or not it references
|
|
|
|
|
* the given variable associated with the given trigger.
|
|
|
|
|
*
|
|
|
|
|
* Return: The VAR_REF field if it does reference the variable, NULL if not
|
|
|
|
|
*/
|
2018-01-16 11:51:56 +09:00
|
|
|
static struct hist_field *
|
|
|
|
|
check_field_for_var_ref(struct hist_field *hist_field,
|
|
|
|
|
struct hist_trigger_data *var_data,
|
|
|
|
|
unsigned int var_idx)
|
|
|
|
|
{
|
2018-12-20 04:09:16 +09:00
|
|
|
WARN_ON(!(hist_field && hist_field->flags & HIST_FIELD_FL_VAR_REF));
|
2018-01-16 11:51:56 +09:00
|
|
|
|
2018-12-20 04:09:16 +09:00
|
|
|
if (hist_field && hist_field->var.idx == var_idx &&
|
|
|
|
|
hist_field->var.hist_data == var_data)
|
|
|
|
|
return hist_field;
|
2018-01-16 11:51:56 +09:00
|
|
|
|
2018-12-20 04:09:16 +09:00
|
|
|
return NULL;
|
2018-01-16 11:51:56 +09:00
|
|
|
}
|
|
|
|
|
|
2018-12-19 05:33:23 +09:00
|
|
|
/**
|
|
|
|
|
* find_var_ref - Check if a trigger has a reference to a trigger variable
|
|
|
|
|
* @hist_data: The hist trigger that might have a reference to the variable
|
|
|
|
|
* @var_data: The hist trigger that owns the variable
|
|
|
|
|
* @var_idx: The trigger variable identifier
|
|
|
|
|
*
|
|
|
|
|
* Check the list of var_refs[] on the first hist trigger to see
|
|
|
|
|
* whether any of them are references to the variable on the second
|
|
|
|
|
* trigger.
|
|
|
|
|
*
|
|
|
|
|
* Return: The VAR_REF field referencing the variable if so, NULL if not
|
|
|
|
|
*/
|
2018-01-16 11:51:56 +09:00
|
|
|
static struct hist_field *find_var_ref(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct hist_trigger_data *var_data,
|
|
|
|
|
unsigned int var_idx)
|
|
|
|
|
{
|
2018-12-20 04:09:16 +09:00
|
|
|
struct hist_field *hist_field;
|
2018-01-16 11:51:56 +09:00
|
|
|
unsigned int i;
|
|
|
|
|
|
2018-12-20 04:09:16 +09:00
|
|
|
for (i = 0; i < hist_data->n_var_refs; i++) {
|
|
|
|
|
hist_field = hist_data->var_refs[i];
|
|
|
|
|
if (check_field_for_var_ref(hist_field, var_data, var_idx))
|
|
|
|
|
return hist_field;
|
2018-01-16 11:51:56 +09:00
|
|
|
}
|
|
|
|
|
|
2018-12-20 04:09:16 +09:00
|
|
|
return NULL;
|
2018-01-16 11:51:56 +09:00
|
|
|
}
|
|
|
|
|
|
2018-12-19 05:33:23 +09:00
|
|
|
/**
|
|
|
|
|
* find_any_var_ref - Check if there is a reference to a given trigger variable
|
|
|
|
|
* @hist_data: The hist trigger
|
|
|
|
|
* @var_idx: The trigger variable identifier
|
|
|
|
|
*
|
|
|
|
|
* Check to see whether the given variable is currently referenced by
|
|
|
|
|
* any other trigger.
|
|
|
|
|
*
|
|
|
|
|
* The trigger the variable is defined on is explicitly excluded - the
|
|
|
|
|
* assumption being that a self-reference doesn't prevent a trigger
|
|
|
|
|
* from being removed.
|
|
|
|
|
*
|
|
|
|
|
* Return: The VAR_REF field referencing the variable if so, NULL if not
|
|
|
|
|
*/
|
2018-01-16 11:51:56 +09:00
|
|
|
static struct hist_field *find_any_var_ref(struct hist_trigger_data *hist_data,
|
|
|
|
|
unsigned int var_idx)
|
|
|
|
|
{
|
|
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
|
|
|
|
struct hist_field *found = NULL;
|
|
|
|
|
struct hist_var_data *var_data;
|
|
|
|
|
|
|
|
|
|
list_for_each_entry(var_data, &tr->hist_vars, list) {
|
|
|
|
|
if (var_data->hist_data == hist_data)
|
|
|
|
|
continue;
|
|
|
|
|
found = find_var_ref(var_data->hist_data, hist_data, var_idx);
|
|
|
|
|
if (found)
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
2018-12-19 05:33:23 +09:00
|
|
|
/**
|
|
|
|
|
* check_var_refs - Check if there is a reference to any of trigger's variables
|
|
|
|
|
* @hist_data: The hist trigger
|
|
|
|
|
*
|
|
|
|
|
* A trigger can define one or more variables. If any one of them is
|
|
|
|
|
* currently referenced by any other trigger, this function will
|
|
|
|
|
* determine that.
|
|
|
|
|
|
|
|
|
|
* Typically used to determine whether or not a trigger can be removed
|
|
|
|
|
* - if there are any references to a trigger's variables, it cannot.
|
|
|
|
|
*
|
|
|
|
|
* Return: True if there is a reference to any of trigger's variables
|
|
|
|
|
*/
|
2018-01-16 11:51:56 +09:00
|
|
|
static bool check_var_refs(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *field;
|
|
|
|
|
bool found = false;
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
for_each_hist_field(i, hist_data) {
|
|
|
|
|
field = hist_data->fields[i];
|
|
|
|
|
if (field && field->flags & HIST_FIELD_FL_VAR) {
|
|
|
|
|
if (find_any_var_ref(hist_data, field->var.idx)) {
|
|
|
|
|
found = true;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_var_data *find_hist_vars(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
|
|
|
|
struct hist_var_data *var_data, *found = NULL;
|
|
|
|
|
|
|
|
|
|
list_for_each_entry(var_data, &tr->hist_vars, list) {
|
|
|
|
|
if (var_data->hist_data == hist_data) {
|
|
|
|
|
found = var_data;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool field_has_hist_vars(struct hist_field *hist_field,
|
|
|
|
|
unsigned int level)
|
|
|
|
|
{
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
if (level > 3)
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
if (!hist_field)
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
if (hist_field->flags & HIST_FIELD_FL_VAR ||
|
|
|
|
|
hist_field->flags & HIST_FIELD_FL_VAR_REF)
|
|
|
|
|
return true;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) {
|
|
|
|
|
struct hist_field *operand;
|
|
|
|
|
|
|
|
|
|
operand = hist_field->operands[i];
|
|
|
|
|
if (field_has_hist_vars(operand, level + 1))
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool has_hist_vars(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *hist_field;
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
for_each_hist_field(i, hist_data) {
|
|
|
|
|
hist_field = hist_data->fields[i];
|
|
|
|
|
if (field_has_hist_vars(hist_field, 0))
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int save_hist_vars(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
|
|
|
|
struct hist_var_data *var_data;
|
|
|
|
|
|
|
|
|
|
var_data = find_hist_vars(hist_data);
|
|
|
|
|
if (var_data)
|
|
|
|
|
return 0;
|
|
|
|
|
|
tracing: Add tracing_check_open_get_tr()
Currently, most files in the tracefs directory test if tracing_disabled is
set. If so, it should return -ENODEV. The tracing_disabled is called when
tracing is found to be broken. Originally it was done in case the ring
buffer was found to be corrupted, and we wanted to prevent reading it from
crashing the kernel. But it's also called if a tracing selftest fails on
boot. It's a one way switch. That is, once it is triggered, tracing is
disabled until reboot.
As most tracefs files can also be used by instances in the tracefs
directory, they need to be carefully done. Each instance has a trace_array
associated to it, and when the instance is removed, the trace_array is
freed. But if an instance is opened with a reference to the trace_array,
then it requires looking up the trace_array to get its ref counter (as there
could be a race with it being deleted and the open itself). Once it is
found, a reference is added to prevent the instance from being removed (and
the trace_array associated with it freed).
Combine the two checks (tracing_disabled and trace_array_get()) into a
single helper function. This will also make it easier to add lockdown to
tracefs later.
Link: http://lkml.kernel.org/r/20191011135458.7399da44@gandalf.local.home
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-10-12 06:39:57 +09:00
|
|
|
if (tracing_check_open_get_tr(tr))
|
2018-01-16 11:51:56 +09:00
|
|
|
return -ENODEV;
|
|
|
|
|
|
|
|
|
|
var_data = kzalloc(sizeof(*var_data), GFP_KERNEL);
|
|
|
|
|
if (!var_data) {
|
|
|
|
|
trace_array_put(tr);
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
var_data->hist_data = hist_data;
|
|
|
|
|
list_add(&var_data->list, &tr->hist_vars);
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void remove_hist_vars(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
|
|
|
|
struct hist_var_data *var_data;
|
|
|
|
|
|
|
|
|
|
var_data = find_hist_vars(hist_data);
|
|
|
|
|
if (!var_data)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
if (WARN_ON(check_var_refs(hist_data)))
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
list_del(&var_data->list);
|
|
|
|
|
|
|
|
|
|
kfree(var_data);
|
|
|
|
|
|
|
|
|
|
trace_array_put(tr);
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
static struct hist_field *find_var_field(struct hist_trigger_data *hist_data,
|
|
|
|
|
const char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *hist_field, *found = NULL;
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
for_each_hist_field(i, hist_data) {
|
|
|
|
|
hist_field = hist_data->fields[i];
|
|
|
|
|
if (hist_field && hist_field->flags & HIST_FIELD_FL_VAR &&
|
|
|
|
|
strcmp(hist_field->var.name, var_name) == 0) {
|
|
|
|
|
found = hist_field;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *find_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
const char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *test_data;
|
|
|
|
|
struct event_trigger_data *test;
|
|
|
|
|
struct hist_field *hist_field;
|
|
|
|
|
|
2019-12-20 11:31:43 +09:00
|
|
|
lockdep_assert_held(&event_mutex);
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
hist_field = find_var_field(hist_data, var_name);
|
|
|
|
|
if (hist_field)
|
|
|
|
|
return hist_field;
|
|
|
|
|
|
2019-12-20 11:31:43 +09:00
|
|
|
list_for_each_entry(test, &file->triggers, list) {
|
2018-01-16 11:51:49 +09:00
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
|
|
|
test_data = test->private_data;
|
|
|
|
|
hist_field = find_var_field(test_data, var_name);
|
|
|
|
|
if (hist_field)
|
|
|
|
|
return hist_field;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
static struct trace_event_file *find_var_file(struct trace_array *tr,
|
|
|
|
|
char *system,
|
|
|
|
|
char *event_name,
|
|
|
|
|
char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *var_hist_data;
|
|
|
|
|
struct hist_var_data *var_data;
|
|
|
|
|
struct trace_event_file *file, *found = NULL;
|
|
|
|
|
|
|
|
|
|
if (system)
|
|
|
|
|
return find_event_file(tr, system, event_name);
|
|
|
|
|
|
|
|
|
|
list_for_each_entry(var_data, &tr->hist_vars, list) {
|
|
|
|
|
var_hist_data = var_data->hist_data;
|
|
|
|
|
file = var_hist_data->event_file;
|
|
|
|
|
if (file == found)
|
|
|
|
|
continue;
|
|
|
|
|
|
|
|
|
|
if (find_var_field(var_hist_data, var_name)) {
|
2018-01-16 11:52:05 +09:00
|
|
|
if (found) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_VAR_NOT_UNIQUE, errpos(var_name));
|
2018-01-16 11:51:56 +09:00
|
|
|
return NULL;
|
2018-01-16 11:52:05 +09:00
|
|
|
}
|
2018-01-16 11:51:56 +09:00
|
|
|
|
|
|
|
|
found = file;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *find_file_var(struct trace_event_file *file,
|
|
|
|
|
const char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *test_data;
|
|
|
|
|
struct event_trigger_data *test;
|
|
|
|
|
struct hist_field *hist_field;
|
|
|
|
|
|
2019-12-20 11:31:43 +09:00
|
|
|
lockdep_assert_held(&event_mutex);
|
|
|
|
|
|
|
|
|
|
list_for_each_entry(test, &file->triggers, list) {
|
2018-01-16 11:51:56 +09:00
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
|
|
|
test_data = test->private_data;
|
|
|
|
|
hist_field = find_var_field(test_data, var_name);
|
|
|
|
|
if (hist_field)
|
|
|
|
|
return hist_field;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:52:00 +09:00
|
|
|
static struct hist_field *
|
|
|
|
|
find_match_var(struct hist_trigger_data *hist_data, char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
|
|
|
|
struct hist_field *hist_field, *found = NULL;
|
|
|
|
|
struct trace_event_file *file;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_actions; i++) {
|
|
|
|
|
struct action_data *data = hist_data->actions[i];
|
|
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
if (data->handler == HANDLER_ONMATCH) {
|
2019-02-14 08:42:43 +09:00
|
|
|
char *system = data->match_data.event_system;
|
|
|
|
|
char *event_name = data->match_data.event;
|
2018-01-16 11:52:00 +09:00
|
|
|
|
|
|
|
|
file = find_var_file(tr, system, event_name, var_name);
|
|
|
|
|
if (!file)
|
|
|
|
|
continue;
|
|
|
|
|
hist_field = find_file_var(file, var_name);
|
|
|
|
|
if (hist_field) {
|
|
|
|
|
if (found) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_VAR_NOT_UNIQUE,
|
|
|
|
|
errpos(var_name));
|
2018-01-16 11:52:00 +09:00
|
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
found = hist_field;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
static struct hist_field *find_event_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
char *system,
|
|
|
|
|
char *event_name,
|
|
|
|
|
char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
|
|
|
|
struct hist_field *hist_field = NULL;
|
|
|
|
|
struct trace_event_file *file;
|
|
|
|
|
|
2018-01-16 11:52:00 +09:00
|
|
|
if (!system || !event_name) {
|
|
|
|
|
hist_field = find_match_var(hist_data, var_name);
|
|
|
|
|
if (IS_ERR(hist_field))
|
|
|
|
|
return NULL;
|
|
|
|
|
if (hist_field)
|
|
|
|
|
return hist_field;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
file = find_var_file(tr, system, event_name, var_name);
|
|
|
|
|
if (!file)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
hist_field = find_file_var(file, var_name);
|
|
|
|
|
|
|
|
|
|
return hist_field;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static u64 hist_field_var_ref(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
|
|
|
|
{
|
|
|
|
|
struct hist_elt_data *elt_data;
|
|
|
|
|
u64 var_val = 0;
|
|
|
|
|
|
2019-04-19 00:18:50 +09:00
|
|
|
if (WARN_ON_ONCE(!elt))
|
|
|
|
|
return var_val;
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
elt_data = elt->private_data;
|
|
|
|
|
var_val = elt_data->var_ref_vals[hist_field->var_ref_idx];
|
|
|
|
|
|
|
|
|
|
return var_val;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool resolve_var_refs(struct hist_trigger_data *hist_data, void *key,
|
|
|
|
|
u64 *var_ref_vals, bool self)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *var_data;
|
|
|
|
|
struct tracing_map_elt *var_elt;
|
|
|
|
|
struct hist_field *hist_field;
|
|
|
|
|
unsigned int i, var_idx;
|
|
|
|
|
bool resolved = true;
|
|
|
|
|
u64 var_val = 0;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_var_refs; i++) {
|
|
|
|
|
hist_field = hist_data->var_refs[i];
|
|
|
|
|
var_idx = hist_field->var.idx;
|
|
|
|
|
var_data = hist_field->var.hist_data;
|
|
|
|
|
|
|
|
|
|
if (var_data == NULL) {
|
|
|
|
|
resolved = false;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if ((self && var_data != hist_data) ||
|
|
|
|
|
(!self && var_data == hist_data))
|
|
|
|
|
continue;
|
|
|
|
|
|
|
|
|
|
var_elt = tracing_map_lookup(var_data->map, key);
|
|
|
|
|
if (!var_elt) {
|
|
|
|
|
resolved = false;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (!tracing_map_var_set(var_elt, var_idx)) {
|
|
|
|
|
resolved = false;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (self || !hist_field->read_once)
|
|
|
|
|
var_val = tracing_map_read_var(var_elt, var_idx);
|
|
|
|
|
else
|
|
|
|
|
var_val = tracing_map_read_var_once(var_elt, var_idx);
|
|
|
|
|
|
|
|
|
|
var_ref_vals[i] = var_val;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return resolved;
|
|
|
|
|
}
|
|
|
|
|
|
2017-09-23 04:58:22 +09:00
|
|
|
static const char *hist_field_name(struct hist_field *field,
|
|
|
|
|
unsigned int level)
|
|
|
|
|
{
|
|
|
|
|
const char *field_name = "";
|
|
|
|
|
|
|
|
|
|
if (level > 1)
|
|
|
|
|
return field_name;
|
|
|
|
|
|
|
|
|
|
if (field->field)
|
|
|
|
|
field_name = field->field->name;
|
2018-01-16 11:52:04 +09:00
|
|
|
else if (field->flags & HIST_FIELD_FL_LOG2 ||
|
|
|
|
|
field->flags & HIST_FIELD_FL_ALIAS)
|
2017-09-23 04:58:23 +09:00
|
|
|
field_name = hist_field_name(field->operands[0], ++level);
|
2018-01-16 11:52:03 +09:00
|
|
|
else if (field->flags & HIST_FIELD_FL_CPU)
|
tracing/histogram: Rename "cpu" to "common_cpu"
commit 1e3bac71c5053c99d438771fc9fa5082ae5d90aa upstream.
Currently the histogram logic allows the user to write "cpu" in as an
event field, and it will record the CPU that the event happened on.
The problem with this is that there's a lot of events that have "cpu"
as a real field, and using "cpu" as the CPU it ran on, makes it
impossible to run histograms on the "cpu" field of events.
For example, if I want to have a histogram on the count of the
workqueue_queue_work event on its cpu field, running:
># echo 'hist:keys=cpu' > events/workqueue/workqueue_queue_work/trigger
Gives a misleading and wrong result.
Change the command to "common_cpu" as no event should have "common_*"
fields as that's a reserved name for fields used by all events. And
this makes sense here as common_cpu would be a field used by all events.
Now we can even do:
># echo 'hist:keys=common_cpu,cpu if cpu < 100' > events/workqueue/workqueue_queue_work/trigger
># cat events/workqueue/workqueue_queue_work/hist
# event histogram
#
# trigger info: hist:keys=common_cpu,cpu:vals=hitcount:sort=hitcount:size=2048 if cpu < 100 [active]
#
{ common_cpu: 0, cpu: 2 } hitcount: 1
{ common_cpu: 0, cpu: 4 } hitcount: 1
{ common_cpu: 7, cpu: 7 } hitcount: 1
{ common_cpu: 0, cpu: 7 } hitcount: 1
{ common_cpu: 0, cpu: 1 } hitcount: 1
{ common_cpu: 0, cpu: 6 } hitcount: 2
{ common_cpu: 0, cpu: 5 } hitcount: 2
{ common_cpu: 1, cpu: 1 } hitcount: 4
{ common_cpu: 6, cpu: 6 } hitcount: 4
{ common_cpu: 5, cpu: 5 } hitcount: 14
{ common_cpu: 4, cpu: 4 } hitcount: 26
{ common_cpu: 0, cpu: 0 } hitcount: 39
{ common_cpu: 2, cpu: 2 } hitcount: 184
Now for backward compatibility, I added a trick. If "cpu" is used, and
the field is not found, it will fall back to "common_cpu" and work as
it did before. This way, it will still work for old programs that use
"cpu" to get the actual CPU, but if the event has a "cpu" as a field, it
will get that event's "cpu" field, which is probably what it wants
anyway.
I updated the tracefs/README to include documentation about both the
common_timestamp and the common_cpu. This way, if that text is present in
the README, then an application can know that common_cpu is supported over
just plain "cpu".
Link: https://lkml.kernel.org/r/20210721110053.26b4f641@oasis.local.home
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Fixes: 8b7622bf94a44 ("tracing: Add cpu field for hist triggers")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-22 00:00:53 +09:00
|
|
|
field_name = "common_cpu";
|
2018-01-16 11:51:56 +09:00
|
|
|
else if (field->flags & HIST_FIELD_FL_EXPR ||
|
|
|
|
|
field->flags & HIST_FIELD_FL_VAR_REF) {
|
|
|
|
|
if (field->system) {
|
|
|
|
|
static char full_name[MAX_FILTER_STR_VAL];
|
|
|
|
|
|
|
|
|
|
strcat(full_name, field->system);
|
|
|
|
|
strcat(full_name, ".");
|
|
|
|
|
strcat(full_name, field->event_name);
|
|
|
|
|
strcat(full_name, ".");
|
|
|
|
|
strcat(full_name, field->name);
|
|
|
|
|
field_name = full_name;
|
|
|
|
|
} else
|
|
|
|
|
field_name = field->name;
|
2018-03-29 05:10:53 +09:00
|
|
|
} else if (field->flags & HIST_FIELD_FL_TIMESTAMP)
|
|
|
|
|
field_name = "common_timestamp";
|
2017-09-23 04:58:22 +09:00
|
|
|
|
|
|
|
|
if (field_name == NULL)
|
|
|
|
|
field_name = "";
|
|
|
|
|
|
|
|
|
|
return field_name;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
static hist_field_fn_t select_value_fn(int field_size, int field_is_signed)
|
|
|
|
|
{
|
|
|
|
|
hist_field_fn_t fn = NULL;
|
|
|
|
|
|
|
|
|
|
switch (field_size) {
|
|
|
|
|
case 8:
|
|
|
|
|
if (field_is_signed)
|
|
|
|
|
fn = hist_field_s64;
|
|
|
|
|
else
|
|
|
|
|
fn = hist_field_u64;
|
|
|
|
|
break;
|
|
|
|
|
case 4:
|
|
|
|
|
if (field_is_signed)
|
|
|
|
|
fn = hist_field_s32;
|
|
|
|
|
else
|
|
|
|
|
fn = hist_field_u32;
|
|
|
|
|
break;
|
|
|
|
|
case 2:
|
|
|
|
|
if (field_is_signed)
|
|
|
|
|
fn = hist_field_s16;
|
|
|
|
|
else
|
|
|
|
|
fn = hist_field_u16;
|
|
|
|
|
break;
|
|
|
|
|
case 1:
|
|
|
|
|
if (field_is_signed)
|
|
|
|
|
fn = hist_field_s8;
|
|
|
|
|
else
|
|
|
|
|
fn = hist_field_u8;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return fn;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int parse_map_size(char *str)
|
|
|
|
|
{
|
|
|
|
|
unsigned long size, map_bits;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
ret = kstrtoul(str, 0, &size);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
|
|
map_bits = ilog2(roundup_pow_of_two(size));
|
|
|
|
|
if (map_bits < TRACING_MAP_BITS_MIN ||
|
|
|
|
|
map_bits > TRACING_MAP_BITS_MAX)
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
else
|
|
|
|
|
ret = map_bits;
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)
|
|
|
|
|
{
|
2018-01-16 11:51:49 +09:00
|
|
|
unsigned int i;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
if (!attrs)
|
|
|
|
|
return;
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
for (i = 0; i < attrs->n_assignments; i++)
|
|
|
|
|
kfree(attrs->assignment_str[i]);
|
|
|
|
|
|
2018-01-16 11:51:57 +09:00
|
|
|
for (i = 0; i < attrs->n_actions; i++)
|
|
|
|
|
kfree(attrs->action_str[i]);
|
|
|
|
|
|
2016-03-04 03:54:59 +09:00
|
|
|
kfree(attrs->name);
|
2016-03-04 03:54:45 +09:00
|
|
|
kfree(attrs->sort_key_str);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
kfree(attrs->keys_str);
|
2016-03-04 03:54:43 +09:00
|
|
|
kfree(attrs->vals_str);
|
2018-01-16 11:52:08 +09:00
|
|
|
kfree(attrs->clock);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
kfree(attrs);
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:57 +09:00
|
|
|
static int parse_action(char *str, struct hist_trigger_attrs *attrs)
|
|
|
|
|
{
|
2018-01-16 11:52:00 +09:00
|
|
|
int ret = -EINVAL;
|
2018-01-16 11:51:57 +09:00
|
|
|
|
|
|
|
|
if (attrs->n_actions >= HIST_ACTIONS_MAX)
|
|
|
|
|
return ret;
|
|
|
|
|
|
2018-12-20 12:38:21 +09:00
|
|
|
if ((str_has_prefix(str, "onmatch(")) ||
|
2019-02-14 08:42:48 +09:00
|
|
|
(str_has_prefix(str, "onmax(")) ||
|
|
|
|
|
(str_has_prefix(str, "onchange("))) {
|
2018-01-16 11:52:00 +09:00
|
|
|
attrs->action_str[attrs->n_actions] = kstrdup(str, GFP_KERNEL);
|
|
|
|
|
if (!attrs->action_str[attrs->n_actions]) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
attrs->n_actions++;
|
|
|
|
|
ret = 0;
|
|
|
|
|
}
|
2018-01-16 11:51:57 +09:00
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2019-04-02 11:30:22 +09:00
|
|
|
static int parse_assignment(struct trace_array *tr,
|
|
|
|
|
char *str, struct hist_trigger_attrs *attrs)
|
2018-01-16 11:51:44 +09:00
|
|
|
{
|
2019-06-29 02:40:20 +09:00
|
|
|
int len, ret = 0;
|
2018-01-16 11:51:44 +09:00
|
|
|
|
2019-06-29 02:40:20 +09:00
|
|
|
if ((len = str_has_prefix(str, "key=")) ||
|
|
|
|
|
(len = str_has_prefix(str, "keys="))) {
|
|
|
|
|
attrs->keys_str = kstrdup(str + len, GFP_KERNEL);
|
2018-01-16 11:51:44 +09:00
|
|
|
if (!attrs->keys_str) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
2019-06-29 02:40:20 +09:00
|
|
|
} else if ((len = str_has_prefix(str, "val=")) ||
|
|
|
|
|
(len = str_has_prefix(str, "vals=")) ||
|
|
|
|
|
(len = str_has_prefix(str, "values="))) {
|
|
|
|
|
attrs->vals_str = kstrdup(str + len, GFP_KERNEL);
|
2018-01-16 11:51:44 +09:00
|
|
|
if (!attrs->vals_str) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
2019-06-29 02:40:20 +09:00
|
|
|
} else if ((len = str_has_prefix(str, "sort="))) {
|
|
|
|
|
attrs->sort_key_str = kstrdup(str + len, GFP_KERNEL);
|
2018-01-16 11:51:44 +09:00
|
|
|
if (!attrs->sort_key_str) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
2018-12-20 12:38:21 +09:00
|
|
|
} else if (str_has_prefix(str, "name=")) {
|
2018-01-16 11:51:44 +09:00
|
|
|
attrs->name = kstrdup(str, GFP_KERNEL);
|
|
|
|
|
if (!attrs->name) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
2019-06-29 02:40:20 +09:00
|
|
|
} else if ((len = str_has_prefix(str, "clock="))) {
|
|
|
|
|
str += len;
|
2018-01-16 11:52:08 +09:00
|
|
|
|
|
|
|
|
str = strstrip(str);
|
|
|
|
|
attrs->clock = kstrdup(str, GFP_KERNEL);
|
|
|
|
|
if (!attrs->clock) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
2019-06-29 02:40:20 +09:00
|
|
|
} else if ((len = str_has_prefix(str, "size="))) {
|
|
|
|
|
int map_bits = parse_map_size(str + len);
|
2018-01-16 11:51:44 +09:00
|
|
|
|
|
|
|
|
if (map_bits < 0) {
|
|
|
|
|
ret = map_bits;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
attrs->map_bits = map_bits;
|
2018-01-16 11:51:49 +09:00
|
|
|
} else {
|
|
|
|
|
char *assignment;
|
|
|
|
|
|
|
|
|
|
if (attrs->n_assignments == TRACING_MAP_VARS_MAX) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_TOO_MANY_VARS, errpos(str));
|
2018-01-16 11:51:49 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
assignment = kstrdup(str, GFP_KERNEL);
|
|
|
|
|
if (!assignment) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
attrs->assignment_str[attrs->n_assignments++] = assignment;
|
|
|
|
|
}
|
2018-01-16 11:51:44 +09:00
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2019-04-02 11:30:22 +09:00
|
|
|
static struct hist_trigger_attrs *
|
|
|
|
|
parse_hist_trigger_attrs(struct trace_array *tr, char *trigger_str)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
{
|
|
|
|
|
struct hist_trigger_attrs *attrs;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
attrs = kzalloc(sizeof(*attrs), GFP_KERNEL);
|
|
|
|
|
if (!attrs)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
while (trigger_str) {
|
|
|
|
|
char *str = strsep(&trigger_str, ":");
|
2019-06-29 02:40:20 +09:00
|
|
|
char *rhs;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
2019-06-29 02:40:20 +09:00
|
|
|
rhs = strchr(str, '=');
|
|
|
|
|
if (rhs) {
|
|
|
|
|
if (!strlen(++rhs)) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
2019-04-02 11:30:22 +09:00
|
|
|
ret = parse_assignment(tr, str, attrs);
|
2018-01-16 11:51:44 +09:00
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
|
|
|
|
} else if (strcmp(str, "pause") == 0)
|
2016-03-04 03:54:46 +09:00
|
|
|
attrs->pause = true;
|
|
|
|
|
else if ((strcmp(str, "cont") == 0) ||
|
|
|
|
|
(strcmp(str, "continue") == 0))
|
|
|
|
|
attrs->cont = true;
|
2016-03-04 03:54:47 +09:00
|
|
|
else if (strcmp(str, "clear") == 0)
|
|
|
|
|
attrs->clear = true;
|
2018-01-16 11:51:44 +09:00
|
|
|
else {
|
2018-01-16 11:51:57 +09:00
|
|
|
ret = parse_action(str, attrs);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (!attrs->keys_str) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:52:08 +09:00
|
|
|
if (!attrs->clock) {
|
|
|
|
|
attrs->clock = kstrdup("global", GFP_KERNEL);
|
|
|
|
|
if (!attrs->clock) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
return attrs;
|
|
|
|
|
free:
|
|
|
|
|
destroy_hist_trigger_attrs(attrs);
|
|
|
|
|
|
|
|
|
|
return ERR_PTR(ret);
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:50 +09:00
|
|
|
static inline void save_comm(char *comm, struct task_struct *task)
|
|
|
|
|
{
|
|
|
|
|
if (!task->pid) {
|
|
|
|
|
strcpy(comm, "<idle>");
|
|
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (WARN_ON_ONCE(task->pid < 0)) {
|
|
|
|
|
strcpy(comm, "<XXX>");
|
|
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
|
2019-03-06 01:11:59 +09:00
|
|
|
strncpy(comm, task->comm, TASK_COMM_LEN);
|
2016-03-04 03:54:50 +09:00
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:53 +09:00
|
|
|
static void hist_elt_data_free(struct hist_elt_data *elt_data)
|
|
|
|
|
{
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < SYNTH_FIELDS_MAX; i++)
|
|
|
|
|
kfree(elt_data->field_var_str[i]);
|
|
|
|
|
|
2018-01-16 11:51:53 +09:00
|
|
|
kfree(elt_data->comm);
|
|
|
|
|
kfree(elt_data);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void hist_trigger_elt_data_free(struct tracing_map_elt *elt)
|
2016-03-04 03:54:50 +09:00
|
|
|
{
|
2018-01-16 11:51:53 +09:00
|
|
|
struct hist_elt_data *elt_data = elt->private_data;
|
|
|
|
|
|
|
|
|
|
hist_elt_data_free(elt_data);
|
2016-03-04 03:54:50 +09:00
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:53 +09:00
|
|
|
static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt)
|
2016-03-04 03:54:50 +09:00
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = elt->map->private_data;
|
2018-01-16 11:51:53 +09:00
|
|
|
unsigned int size = TASK_COMM_LEN;
|
|
|
|
|
struct hist_elt_data *elt_data;
|
2016-03-04 03:54:50 +09:00
|
|
|
struct hist_field *key_field;
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
unsigned int i, n_str;
|
2016-03-04 03:54:50 +09:00
|
|
|
|
2018-01-16 11:51:53 +09:00
|
|
|
elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL);
|
|
|
|
|
if (!elt_data)
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
2016-03-04 03:54:50 +09:00
|
|
|
for_each_hist_key_field(i, hist_data) {
|
|
|
|
|
key_field = hist_data->fields[i];
|
|
|
|
|
|
|
|
|
|
if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
|
2018-01-16 11:51:53 +09:00
|
|
|
elt_data->comm = kzalloc(size, GFP_KERNEL);
|
|
|
|
|
if (!elt_data->comm) {
|
|
|
|
|
kfree(elt_data);
|
2016-03-04 03:54:50 +09:00
|
|
|
return -ENOMEM;
|
2018-01-16 11:51:53 +09:00
|
|
|
}
|
2016-03-04 03:54:50 +09:00
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
n_str = hist_data->n_field_var_str + hist_data->n_save_var_str;
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
|
|
|
|
|
size = STR_VAR_LEN_MAX;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < n_str; i++) {
|
|
|
|
|
elt_data->field_var_str[i] = kzalloc(size, GFP_KERNEL);
|
|
|
|
|
if (!elt_data->field_var_str[i]) {
|
|
|
|
|
hist_elt_data_free(elt_data);
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:53 +09:00
|
|
|
elt->private_data = elt_data;
|
|
|
|
|
|
2016-03-04 03:54:50 +09:00
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:53 +09:00
|
|
|
static void hist_trigger_elt_data_init(struct tracing_map_elt *elt)
|
2016-03-04 03:54:50 +09:00
|
|
|
{
|
2018-01-16 11:51:53 +09:00
|
|
|
struct hist_elt_data *elt_data = elt->private_data;
|
2016-03-04 03:54:50 +09:00
|
|
|
|
2018-01-16 11:51:53 +09:00
|
|
|
if (elt_data->comm)
|
|
|
|
|
save_comm(elt_data->comm, current);
|
2016-03-04 03:54:50 +09:00
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:53 +09:00
|
|
|
static const struct tracing_map_ops hist_trigger_elt_data_ops = {
|
|
|
|
|
.elt_alloc = hist_trigger_elt_data_alloc,
|
|
|
|
|
.elt_free = hist_trigger_elt_data_free,
|
|
|
|
|
.elt_init = hist_trigger_elt_data_init,
|
2016-03-04 03:54:50 +09:00
|
|
|
};
|
|
|
|
|
|
2018-01-16 11:51:51 +09:00
|
|
|
static const char *get_hist_field_flags(struct hist_field *hist_field)
|
|
|
|
|
{
|
|
|
|
|
const char *flags_str = NULL;
|
|
|
|
|
|
|
|
|
|
if (hist_field->flags & HIST_FIELD_FL_HEX)
|
|
|
|
|
flags_str = "hex";
|
|
|
|
|
else if (hist_field->flags & HIST_FIELD_FL_SYM)
|
|
|
|
|
flags_str = "sym";
|
|
|
|
|
else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET)
|
|
|
|
|
flags_str = "sym-offset";
|
|
|
|
|
else if (hist_field->flags & HIST_FIELD_FL_EXECNAME)
|
|
|
|
|
flags_str = "execname";
|
|
|
|
|
else if (hist_field->flags & HIST_FIELD_FL_SYSCALL)
|
|
|
|
|
flags_str = "syscall";
|
|
|
|
|
else if (hist_field->flags & HIST_FIELD_FL_LOG2)
|
|
|
|
|
flags_str = "log2";
|
|
|
|
|
else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP_USECS)
|
|
|
|
|
flags_str = "usecs";
|
|
|
|
|
|
|
|
|
|
return flags_str;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:52 +09:00
|
|
|
static void expr_field_str(struct hist_field *field, char *expr)
|
|
|
|
|
{
|
2018-01-16 11:51:56 +09:00
|
|
|
if (field->flags & HIST_FIELD_FL_VAR_REF)
|
|
|
|
|
strcat(expr, "$");
|
|
|
|
|
|
2018-01-16 11:51:52 +09:00
|
|
|
strcat(expr, hist_field_name(field, 0));
|
|
|
|
|
|
2018-03-29 05:10:54 +09:00
|
|
|
if (field->flags && !(field->flags & HIST_FIELD_FL_VAR_REF)) {
|
2018-01-16 11:51:52 +09:00
|
|
|
const char *flags_str = get_hist_field_flags(field);
|
|
|
|
|
|
|
|
|
|
if (flags_str) {
|
|
|
|
|
strcat(expr, ".");
|
|
|
|
|
strcat(expr, flags_str);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static char *expr_str(struct hist_field *field, unsigned int level)
|
|
|
|
|
{
|
|
|
|
|
char *expr;
|
|
|
|
|
|
|
|
|
|
if (level > 1)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
expr = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
|
|
|
|
|
if (!expr)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
if (!field->operands[0]) {
|
|
|
|
|
expr_field_str(field, expr);
|
|
|
|
|
return expr;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (field->operator == FIELD_OP_UNARY_MINUS) {
|
|
|
|
|
char *subexpr;
|
|
|
|
|
|
|
|
|
|
strcat(expr, "-(");
|
|
|
|
|
subexpr = expr_str(field->operands[0], ++level);
|
|
|
|
|
if (!subexpr) {
|
|
|
|
|
kfree(expr);
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
strcat(expr, subexpr);
|
|
|
|
|
strcat(expr, ")");
|
|
|
|
|
|
|
|
|
|
kfree(subexpr);
|
|
|
|
|
|
|
|
|
|
return expr;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
expr_field_str(field->operands[0], expr);
|
|
|
|
|
|
|
|
|
|
switch (field->operator) {
|
|
|
|
|
case FIELD_OP_MINUS:
|
|
|
|
|
strcat(expr, "-");
|
|
|
|
|
break;
|
|
|
|
|
case FIELD_OP_PLUS:
|
|
|
|
|
strcat(expr, "+");
|
|
|
|
|
break;
|
|
|
|
|
default:
|
|
|
|
|
kfree(expr);
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
expr_field_str(field->operands[1], expr);
|
|
|
|
|
|
|
|
|
|
return expr;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int contains_operator(char *str)
|
|
|
|
|
{
|
|
|
|
|
enum field_op_id field_op = FIELD_OP_NONE;
|
|
|
|
|
char *op;
|
|
|
|
|
|
|
|
|
|
op = strpbrk(str, "+-");
|
|
|
|
|
if (!op)
|
|
|
|
|
return FIELD_OP_NONE;
|
|
|
|
|
|
|
|
|
|
switch (*op) {
|
|
|
|
|
case '-':
|
2021-07-08 00:08:21 +09:00
|
|
|
/*
|
|
|
|
|
* Unfortunately, the modifier ".sym-offset"
|
|
|
|
|
* can confuse things.
|
|
|
|
|
*/
|
|
|
|
|
if (op - str >= 4 && !strncmp(op - 4, ".sym-offset", 11))
|
|
|
|
|
return FIELD_OP_NONE;
|
|
|
|
|
|
2018-01-16 11:51:52 +09:00
|
|
|
if (*str == '-')
|
|
|
|
|
field_op = FIELD_OP_UNARY_MINUS;
|
|
|
|
|
else
|
|
|
|
|
field_op = FIELD_OP_MINUS;
|
|
|
|
|
break;
|
|
|
|
|
case '+':
|
|
|
|
|
field_op = FIELD_OP_PLUS;
|
|
|
|
|
break;
|
|
|
|
|
default:
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return field_op;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Fix histogram code when expression has same var as value
commit 8bcebc77e85f3d7536f96845a0fe94b1dddb6af0 upstream.
While working on a tool to convert SQL syntex into the histogram language of
the kernel, I discovered the following bug:
# echo 'first u64 start_time u64 end_time pid_t pid u64 delta' >> synthetic_events
# echo 'hist:keys=pid:start=common_timestamp' > events/sched/sched_waking/trigger
# echo 'hist:keys=next_pid:delta=common_timestamp-$start,start2=$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger
Would not display any histograms in the sched_switch histogram side.
But if I were to swap the location of
"delta=common_timestamp-$start" with "start2=$start"
Such that the last line had:
# echo 'hist:keys=next_pid:start2=$start,delta=common_timestamp-$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger
The histogram works as expected.
What I found out is that the expressions clear out the value once it is
resolved. As the variables are resolved in the order listed, when
processing:
delta=common_timestamp-$start
The $start is cleared. When it gets to "start2=$start", it errors out with
"unresolved symbol" (which is silent as this happens at the location of the
trace), and the histogram is dropped.
When processing the histogram for variable references, instead of adding a
new reference for a variable used twice, use the same reference. That way,
not only is it more efficient, but the order will no longer matter in
processing of the variables.
From Tom Zanussi:
"Just to clarify some more about what the problem was is that without
your patch, we would have two separate references to the same variable,
and during resolve_var_refs(), they'd both want to be resolved
separately, so in this case, since the first reference to start wasn't
part of an expression, it wouldn't get the read-once flag set, so would
be read normally, and then the second reference would do the read-once
read and also be read but using read-once. So everything worked and
you didn't see a problem:
from: start2=$start,delta=common_timestamp-$start
In the second case, when you switched them around, the first reference
would be resolved by doing the read-once, and following that the second
reference would try to resolve and see that the variable had already
been read, so failed as unset, which caused it to short-circuit out and
not do the trigger action to generate the synthetic event:
to: delta=common_timestamp-$start,start2=$start
With your patch, we only have the single resolution which happens
correctly the one time it's resolved, so this can't happen."
Link: https://lore.kernel.org/r/20200116154216.58ca08eb@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: 067fe038e70f6 ("tracing: Add variable reference handling to hist triggers")
Reviewed-by: Tom Zanuss <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-21 03:07:31 +09:00
|
|
|
static void get_hist_field(struct hist_field *hist_field)
|
|
|
|
|
{
|
|
|
|
|
hist_field->ref++;
|
|
|
|
|
}
|
|
|
|
|
|
2018-12-19 05:33:24 +09:00
|
|
|
static void __destroy_hist_field(struct hist_field *hist_field)
|
|
|
|
|
{
|
tracing: Fix histogram code when expression has same var as value
commit 8bcebc77e85f3d7536f96845a0fe94b1dddb6af0 upstream.
While working on a tool to convert SQL syntex into the histogram language of
the kernel, I discovered the following bug:
# echo 'first u64 start_time u64 end_time pid_t pid u64 delta' >> synthetic_events
# echo 'hist:keys=pid:start=common_timestamp' > events/sched/sched_waking/trigger
# echo 'hist:keys=next_pid:delta=common_timestamp-$start,start2=$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger
Would not display any histograms in the sched_switch histogram side.
But if I were to swap the location of
"delta=common_timestamp-$start" with "start2=$start"
Such that the last line had:
# echo 'hist:keys=next_pid:start2=$start,delta=common_timestamp-$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger
The histogram works as expected.
What I found out is that the expressions clear out the value once it is
resolved. As the variables are resolved in the order listed, when
processing:
delta=common_timestamp-$start
The $start is cleared. When it gets to "start2=$start", it errors out with
"unresolved symbol" (which is silent as this happens at the location of the
trace), and the histogram is dropped.
When processing the histogram for variable references, instead of adding a
new reference for a variable used twice, use the same reference. That way,
not only is it more efficient, but the order will no longer matter in
processing of the variables.
From Tom Zanussi:
"Just to clarify some more about what the problem was is that without
your patch, we would have two separate references to the same variable,
and during resolve_var_refs(), they'd both want to be resolved
separately, so in this case, since the first reference to start wasn't
part of an expression, it wouldn't get the read-once flag set, so would
be read normally, and then the second reference would do the read-once
read and also be read but using read-once. So everything worked and
you didn't see a problem:
from: start2=$start,delta=common_timestamp-$start
In the second case, when you switched them around, the first reference
would be resolved by doing the read-once, and following that the second
reference would try to resolve and see that the variable had already
been read, so failed as unset, which caused it to short-circuit out and
not do the trigger action to generate the synthetic event:
to: delta=common_timestamp-$start,start2=$start
With your patch, we only have the single resolution which happens
correctly the one time it's resolved, so this can't happen."
Link: https://lore.kernel.org/r/20200116154216.58ca08eb@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: 067fe038e70f6 ("tracing: Add variable reference handling to hist triggers")
Reviewed-by: Tom Zanuss <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-21 03:07:31 +09:00
|
|
|
if (--hist_field->ref > 1)
|
|
|
|
|
return;
|
|
|
|
|
|
2018-12-19 05:33:24 +09:00
|
|
|
kfree(hist_field->var.name);
|
|
|
|
|
kfree(hist_field->name);
|
|
|
|
|
kfree(hist_field->type);
|
|
|
|
|
|
2020-04-22 15:15:06 +09:00
|
|
|
kfree(hist_field->system);
|
|
|
|
|
kfree(hist_field->event_name);
|
|
|
|
|
|
2018-12-19 05:33:24 +09:00
|
|
|
kfree(hist_field);
|
|
|
|
|
}
|
|
|
|
|
|
2017-09-23 04:58:23 +09:00
|
|
|
static void destroy_hist_field(struct hist_field *hist_field,
|
|
|
|
|
unsigned int level)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
{
|
2017-09-23 04:58:23 +09:00
|
|
|
unsigned int i;
|
|
|
|
|
|
2018-01-16 11:51:52 +09:00
|
|
|
if (level > 3)
|
2017-09-23 04:58:23 +09:00
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
if (!hist_field)
|
|
|
|
|
return;
|
|
|
|
|
|
2018-12-19 05:33:24 +09:00
|
|
|
if (hist_field->flags & HIST_FIELD_FL_VAR_REF)
|
|
|
|
|
return; /* var refs will be destroyed separately */
|
|
|
|
|
|
2017-09-23 04:58:23 +09:00
|
|
|
for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++)
|
|
|
|
|
destroy_hist_field(hist_field->operands[i], level + 1);
|
|
|
|
|
|
2018-12-19 05:33:24 +09:00
|
|
|
__destroy_hist_field(hist_field);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:47 +09:00
|
|
|
static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct ftrace_event_field *field,
|
2018-01-16 11:51:49 +09:00
|
|
|
unsigned long flags,
|
|
|
|
|
char *var_name)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
{
|
|
|
|
|
struct hist_field *hist_field;
|
|
|
|
|
|
|
|
|
|
if (field && is_function_field(field))
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
hist_field = kzalloc(sizeof(struct hist_field), GFP_KERNEL);
|
|
|
|
|
if (!hist_field)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
tracing: Fix histogram code when expression has same var as value
commit 8bcebc77e85f3d7536f96845a0fe94b1dddb6af0 upstream.
While working on a tool to convert SQL syntex into the histogram language of
the kernel, I discovered the following bug:
# echo 'first u64 start_time u64 end_time pid_t pid u64 delta' >> synthetic_events
# echo 'hist:keys=pid:start=common_timestamp' > events/sched/sched_waking/trigger
# echo 'hist:keys=next_pid:delta=common_timestamp-$start,start2=$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger
Would not display any histograms in the sched_switch histogram side.
But if I were to swap the location of
"delta=common_timestamp-$start" with "start2=$start"
Such that the last line had:
# echo 'hist:keys=next_pid:start2=$start,delta=common_timestamp-$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger
The histogram works as expected.
What I found out is that the expressions clear out the value once it is
resolved. As the variables are resolved in the order listed, when
processing:
delta=common_timestamp-$start
The $start is cleared. When it gets to "start2=$start", it errors out with
"unresolved symbol" (which is silent as this happens at the location of the
trace), and the histogram is dropped.
When processing the histogram for variable references, instead of adding a
new reference for a variable used twice, use the same reference. That way,
not only is it more efficient, but the order will no longer matter in
processing of the variables.
From Tom Zanussi:
"Just to clarify some more about what the problem was is that without
your patch, we would have two separate references to the same variable,
and during resolve_var_refs(), they'd both want to be resolved
separately, so in this case, since the first reference to start wasn't
part of an expression, it wouldn't get the read-once flag set, so would
be read normally, and then the second reference would do the read-once
read and also be read but using read-once. So everything worked and
you didn't see a problem:
from: start2=$start,delta=common_timestamp-$start
In the second case, when you switched them around, the first reference
would be resolved by doing the read-once, and following that the second
reference would try to resolve and see that the variable had already
been read, so failed as unset, which caused it to short-circuit out and
not do the trigger action to generate the synthetic event:
to: delta=common_timestamp-$start,start2=$start
With your patch, we only have the single resolution which happens
correctly the one time it's resolved, so this can't happen."
Link: https://lore.kernel.org/r/20200116154216.58ca08eb@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: 067fe038e70f6 ("tracing: Add variable reference handling to hist triggers")
Reviewed-by: Tom Zanuss <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-21 03:07:31 +09:00
|
|
|
hist_field->ref = 1;
|
|
|
|
|
|
2018-01-16 11:51:47 +09:00
|
|
|
hist_field->hist_data = hist_data;
|
|
|
|
|
|
2018-01-16 11:52:04 +09:00
|
|
|
if (flags & HIST_FIELD_FL_EXPR || flags & HIST_FIELD_FL_ALIAS)
|
2018-01-16 11:51:52 +09:00
|
|
|
goto out; /* caller will populate */
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
if (flags & HIST_FIELD_FL_VAR_REF) {
|
|
|
|
|
hist_field->fn = hist_field_var_ref;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
if (flags & HIST_FIELD_FL_HITCOUNT) {
|
|
|
|
|
hist_field->fn = hist_field_counter;
|
2018-01-16 11:51:55 +09:00
|
|
|
hist_field->size = sizeof(u64);
|
|
|
|
|
hist_field->type = kstrdup("u64", GFP_KERNEL);
|
|
|
|
|
if (!hist_field->type)
|
|
|
|
|
goto free;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:52 +09:00
|
|
|
if (flags & HIST_FIELD_FL_STACKTRACE) {
|
|
|
|
|
hist_field->fn = hist_field_none;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:55:02 +09:00
|
|
|
if (flags & HIST_FIELD_FL_LOG2) {
|
2017-09-23 04:58:23 +09:00
|
|
|
unsigned long fl = flags & ~HIST_FIELD_FL_LOG2;
|
2016-03-04 03:55:02 +09:00
|
|
|
hist_field->fn = hist_field_log2;
|
2018-01-16 11:51:49 +09:00
|
|
|
hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL);
|
2017-09-23 04:58:23 +09:00
|
|
|
hist_field->size = hist_field->operands[0]->size;
|
2018-01-16 11:51:55 +09:00
|
|
|
hist_field->type = kstrdup(hist_field->operands[0]->type, GFP_KERNEL);
|
|
|
|
|
if (!hist_field->type)
|
|
|
|
|
goto free;
|
2016-03-04 03:55:02 +09:00
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:45 +09:00
|
|
|
if (flags & HIST_FIELD_FL_TIMESTAMP) {
|
|
|
|
|
hist_field->fn = hist_field_timestamp;
|
|
|
|
|
hist_field->size = sizeof(u64);
|
2018-01-16 11:51:55 +09:00
|
|
|
hist_field->type = kstrdup("u64", GFP_KERNEL);
|
|
|
|
|
if (!hist_field->type)
|
|
|
|
|
goto free;
|
2018-01-16 11:51:45 +09:00
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:52:03 +09:00
|
|
|
if (flags & HIST_FIELD_FL_CPU) {
|
|
|
|
|
hist_field->fn = hist_field_cpu;
|
|
|
|
|
hist_field->size = sizeof(int);
|
|
|
|
|
hist_field->type = kstrdup("unsigned int", GFP_KERNEL);
|
|
|
|
|
if (!hist_field->type)
|
|
|
|
|
goto free;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2016-04-26 04:01:27 +09:00
|
|
|
if (WARN_ON_ONCE(!field))
|
|
|
|
|
goto out;
|
|
|
|
|
|
2021-07-15 13:02:06 +09:00
|
|
|
/* Pointers to strings are just pointers and dangerous to dereference */
|
|
|
|
|
if (is_string_field(field) &&
|
|
|
|
|
(field->filter_type != FILTER_PTR_STRING)) {
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
flags |= HIST_FIELD_FL_STRING;
|
2016-03-04 03:54:53 +09:00
|
|
|
|
2018-01-16 11:51:55 +09:00
|
|
|
hist_field->size = MAX_FILTER_STR_VAL;
|
|
|
|
|
hist_field->type = kstrdup(field->type, GFP_KERNEL);
|
|
|
|
|
if (!hist_field->type)
|
|
|
|
|
goto free;
|
|
|
|
|
|
2016-03-04 03:54:53 +09:00
|
|
|
if (field->filter_type == FILTER_STATIC_STRING)
|
|
|
|
|
hist_field->fn = hist_field_string;
|
|
|
|
|
else if (field->filter_type == FILTER_DYN_STRING)
|
|
|
|
|
hist_field->fn = hist_field_dynstring;
|
|
|
|
|
else
|
|
|
|
|
hist_field->fn = hist_field_pstring;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
} else {
|
2018-01-16 11:51:55 +09:00
|
|
|
hist_field->size = field->size;
|
|
|
|
|
hist_field->is_signed = field->is_signed;
|
|
|
|
|
hist_field->type = kstrdup(field->type, GFP_KERNEL);
|
|
|
|
|
if (!hist_field->type)
|
|
|
|
|
goto free;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
hist_field->fn = select_value_fn(field->size,
|
|
|
|
|
field->is_signed);
|
|
|
|
|
if (!hist_field->fn) {
|
2017-09-23 04:58:23 +09:00
|
|
|
destroy_hist_field(hist_field, 0);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
hist_field->field = field;
|
|
|
|
|
hist_field->flags = flags;
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
if (var_name) {
|
|
|
|
|
hist_field->var.name = kstrdup(var_name, GFP_KERNEL);
|
|
|
|
|
if (!hist_field->var.name)
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
return hist_field;
|
2018-01-16 11:51:49 +09:00
|
|
|
free:
|
|
|
|
|
destroy_hist_field(hist_field, 0);
|
|
|
|
|
return NULL;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void destroy_hist_fields(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
for (i = 0; i < HIST_FIELDS_MAX; i++) {
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
if (hist_data->fields[i]) {
|
2017-09-23 04:58:23 +09:00
|
|
|
destroy_hist_field(hist_data->fields[i], 0);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
hist_data->fields[i] = NULL;
|
|
|
|
|
}
|
|
|
|
|
}
|
2018-12-19 05:33:24 +09:00
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_var_refs; i++) {
|
|
|
|
|
WARN_ON(!(hist_data->var_refs[i]->flags & HIST_FIELD_FL_VAR_REF));
|
|
|
|
|
__destroy_hist_field(hist_data->var_refs[i]);
|
|
|
|
|
hist_data->var_refs[i] = NULL;
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
static int init_var_ref(struct hist_field *ref_field,
|
|
|
|
|
struct hist_field *var_field,
|
|
|
|
|
char *system, char *event_name)
|
|
|
|
|
{
|
|
|
|
|
int err = 0;
|
|
|
|
|
|
|
|
|
|
ref_field->var.idx = var_field->var.idx;
|
|
|
|
|
ref_field->var.hist_data = var_field->hist_data;
|
|
|
|
|
ref_field->size = var_field->size;
|
|
|
|
|
ref_field->is_signed = var_field->is_signed;
|
|
|
|
|
ref_field->flags |= var_field->flags &
|
|
|
|
|
(HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
|
|
|
|
|
|
|
|
|
|
if (system) {
|
|
|
|
|
ref_field->system = kstrdup(system, GFP_KERNEL);
|
|
|
|
|
if (!ref_field->system)
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (event_name) {
|
|
|
|
|
ref_field->event_name = kstrdup(event_name, GFP_KERNEL);
|
|
|
|
|
if (!ref_field->event_name) {
|
|
|
|
|
err = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:52:04 +09:00
|
|
|
if (var_field->var.name) {
|
|
|
|
|
ref_field->name = kstrdup(var_field->var.name, GFP_KERNEL);
|
|
|
|
|
if (!ref_field->name) {
|
|
|
|
|
err = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
} else if (var_field->name) {
|
|
|
|
|
ref_field->name = kstrdup(var_field->name, GFP_KERNEL);
|
|
|
|
|
if (!ref_field->name) {
|
|
|
|
|
err = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
2018-01-16 11:51:56 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
ref_field->type = kstrdup(var_field->type, GFP_KERNEL);
|
|
|
|
|
if (!ref_field->type) {
|
|
|
|
|
err = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
return err;
|
|
|
|
|
free:
|
|
|
|
|
kfree(ref_field->system);
|
|
|
|
|
kfree(ref_field->event_name);
|
|
|
|
|
kfree(ref_field->name);
|
|
|
|
|
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2020-01-30 11:18:18 +09:00
|
|
|
static int find_var_ref_idx(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct hist_field *var_field)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *ref_field;
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_var_refs; i++) {
|
|
|
|
|
ref_field = hist_data->var_refs[i];
|
|
|
|
|
if (ref_field->var.idx == var_field->var.idx &&
|
|
|
|
|
ref_field->var.hist_data == var_field->hist_data)
|
|
|
|
|
return i;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return -ENOENT;
|
|
|
|
|
}
|
|
|
|
|
|
2018-12-19 05:33:23 +09:00
|
|
|
/**
|
|
|
|
|
* create_var_ref - Create a variable reference and attach it to trigger
|
|
|
|
|
* @hist_data: The trigger that will be referencing the variable
|
|
|
|
|
* @var_field: The VAR field to create a reference to
|
|
|
|
|
* @system: The optional system string
|
|
|
|
|
* @event_name: The optional event_name string
|
|
|
|
|
*
|
|
|
|
|
* Given a variable hist_field, create a VAR_REF hist_field that
|
|
|
|
|
* represents a reference to it.
|
|
|
|
|
*
|
|
|
|
|
* This function also adds the reference to the trigger that
|
|
|
|
|
* now references the variable.
|
|
|
|
|
*
|
|
|
|
|
* Return: The VAR_REF field if successful, NULL if not
|
|
|
|
|
*/
|
|
|
|
|
static struct hist_field *create_var_ref(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct hist_field *var_field,
|
2018-01-16 11:51:56 +09:00
|
|
|
char *system, char *event_name)
|
|
|
|
|
{
|
|
|
|
|
unsigned long flags = HIST_FIELD_FL_VAR_REF;
|
|
|
|
|
struct hist_field *ref_field;
|
tracing: Fix histogram code when expression has same var as value
commit 8bcebc77e85f3d7536f96845a0fe94b1dddb6af0 upstream.
While working on a tool to convert SQL syntex into the histogram language of
the kernel, I discovered the following bug:
# echo 'first u64 start_time u64 end_time pid_t pid u64 delta' >> synthetic_events
# echo 'hist:keys=pid:start=common_timestamp' > events/sched/sched_waking/trigger
# echo 'hist:keys=next_pid:delta=common_timestamp-$start,start2=$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger
Would not display any histograms in the sched_switch histogram side.
But if I were to swap the location of
"delta=common_timestamp-$start" with "start2=$start"
Such that the last line had:
# echo 'hist:keys=next_pid:start2=$start,delta=common_timestamp-$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger
The histogram works as expected.
What I found out is that the expressions clear out the value once it is
resolved. As the variables are resolved in the order listed, when
processing:
delta=common_timestamp-$start
The $start is cleared. When it gets to "start2=$start", it errors out with
"unresolved symbol" (which is silent as this happens at the location of the
trace), and the histogram is dropped.
When processing the histogram for variable references, instead of adding a
new reference for a variable used twice, use the same reference. That way,
not only is it more efficient, but the order will no longer matter in
processing of the variables.
From Tom Zanussi:
"Just to clarify some more about what the problem was is that without
your patch, we would have two separate references to the same variable,
and during resolve_var_refs(), they'd both want to be resolved
separately, so in this case, since the first reference to start wasn't
part of an expression, it wouldn't get the read-once flag set, so would
be read normally, and then the second reference would do the read-once
read and also be read but using read-once. So everything worked and
you didn't see a problem:
from: start2=$start,delta=common_timestamp-$start
In the second case, when you switched them around, the first reference
would be resolved by doing the read-once, and following that the second
reference would try to resolve and see that the variable had already
been read, so failed as unset, which caused it to short-circuit out and
not do the trigger action to generate the synthetic event:
to: delta=common_timestamp-$start,start2=$start
With your patch, we only have the single resolution which happens
correctly the one time it's resolved, so this can't happen."
Link: https://lore.kernel.org/r/20200116154216.58ca08eb@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: 067fe038e70f6 ("tracing: Add variable reference handling to hist triggers")
Reviewed-by: Tom Zanuss <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-21 03:07:31 +09:00
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
/* Check if the variable already exists */
|
|
|
|
|
for (i = 0; i < hist_data->n_var_refs; i++) {
|
|
|
|
|
ref_field = hist_data->var_refs[i];
|
|
|
|
|
if (ref_field->var.idx == var_field->var.idx &&
|
|
|
|
|
ref_field->var.hist_data == var_field->hist_data) {
|
|
|
|
|
get_hist_field(ref_field);
|
|
|
|
|
return ref_field;
|
|
|
|
|
}
|
|
|
|
|
}
|
2018-01-16 11:51:56 +09:00
|
|
|
|
|
|
|
|
ref_field = create_hist_field(var_field->hist_data, NULL, flags, NULL);
|
|
|
|
|
if (ref_field) {
|
|
|
|
|
if (init_var_ref(ref_field, var_field, system, event_name)) {
|
|
|
|
|
destroy_hist_field(ref_field, 0);
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
2018-12-19 05:33:23 +09:00
|
|
|
|
|
|
|
|
hist_data->var_refs[hist_data->n_var_refs] = ref_field;
|
|
|
|
|
ref_field->var_ref_idx = hist_data->n_var_refs++;
|
2018-01-16 11:51:56 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return ref_field;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool is_var_ref(char *var_name)
|
|
|
|
|
{
|
|
|
|
|
if (!var_name || strlen(var_name) < 2 || var_name[0] != '$')
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static char *field_name_from_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
char *var_name)
|
|
|
|
|
{
|
|
|
|
|
char *name, *field;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) {
|
|
|
|
|
name = hist_data->attrs->var_defs.name[i];
|
|
|
|
|
|
|
|
|
|
if (strcmp(var_name, name) == 0) {
|
|
|
|
|
field = hist_data->attrs->var_defs.expr[i];
|
|
|
|
|
if (contains_operator(field) || is_var_ref(field))
|
|
|
|
|
continue;
|
|
|
|
|
return field;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static char *local_field_var_ref(struct hist_trigger_data *hist_data,
|
|
|
|
|
char *system, char *event_name,
|
|
|
|
|
char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_call *call;
|
|
|
|
|
|
|
|
|
|
if (system && event_name) {
|
|
|
|
|
call = hist_data->event_file->event_call;
|
|
|
|
|
|
|
|
|
|
if (strcmp(system, call->class->system) != 0)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
if (strcmp(event_name, trace_event_name(call)) != 0)
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (!!system != !!event_name)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
if (!is_var_ref(var_name))
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
var_name++;
|
|
|
|
|
|
|
|
|
|
return field_name_from_var(hist_data, var_name);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *parse_var_ref(struct hist_trigger_data *hist_data,
|
|
|
|
|
char *system, char *event_name,
|
|
|
|
|
char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *var_field = NULL, *ref_field = NULL;
|
2019-04-02 11:30:22 +09:00
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
2018-01-16 11:51:56 +09:00
|
|
|
|
|
|
|
|
if (!is_var_ref(var_name))
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
var_name++;
|
|
|
|
|
|
|
|
|
|
var_field = find_event_var(hist_data, system, event_name, var_name);
|
|
|
|
|
if (var_field)
|
2018-12-19 05:33:23 +09:00
|
|
|
ref_field = create_var_ref(hist_data, var_field,
|
|
|
|
|
system, event_name);
|
2018-01-16 11:51:56 +09:00
|
|
|
|
2018-01-16 11:52:05 +09:00
|
|
|
if (!ref_field)
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_VAR_NOT_FOUND, errpos(var_name));
|
2018-01-16 11:52:05 +09:00
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
return ref_field;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:52 +09:00
|
|
|
static struct ftrace_event_field *
|
|
|
|
|
parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file,
|
|
|
|
|
char *field_str, unsigned long *flags)
|
|
|
|
|
{
|
|
|
|
|
struct ftrace_event_field *field = NULL;
|
|
|
|
|
char *field_name, *modifier, *str;
|
2019-04-02 11:30:22 +09:00
|
|
|
struct trace_array *tr = file->tr;
|
2018-01-16 11:51:52 +09:00
|
|
|
|
|
|
|
|
modifier = str = kstrdup(field_str, GFP_KERNEL);
|
|
|
|
|
if (!modifier)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
field_name = strsep(&modifier, ".");
|
|
|
|
|
if (modifier) {
|
|
|
|
|
if (strcmp(modifier, "hex") == 0)
|
|
|
|
|
*flags |= HIST_FIELD_FL_HEX;
|
|
|
|
|
else if (strcmp(modifier, "sym") == 0)
|
|
|
|
|
*flags |= HIST_FIELD_FL_SYM;
|
|
|
|
|
else if (strcmp(modifier, "sym-offset") == 0)
|
|
|
|
|
*flags |= HIST_FIELD_FL_SYM_OFFSET;
|
|
|
|
|
else if ((strcmp(modifier, "execname") == 0) &&
|
|
|
|
|
(strcmp(field_name, "common_pid") == 0))
|
|
|
|
|
*flags |= HIST_FIELD_FL_EXECNAME;
|
|
|
|
|
else if (strcmp(modifier, "syscall") == 0)
|
|
|
|
|
*flags |= HIST_FIELD_FL_SYSCALL;
|
|
|
|
|
else if (strcmp(modifier, "log2") == 0)
|
|
|
|
|
*flags |= HIST_FIELD_FL_LOG2;
|
|
|
|
|
else if (strcmp(modifier, "usecs") == 0)
|
|
|
|
|
*flags |= HIST_FIELD_FL_TIMESTAMP_USECS;
|
|
|
|
|
else {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_BAD_FIELD_MODIFIER, errpos(modifier));
|
2018-01-16 11:51:52 +09:00
|
|
|
field = ERR_PTR(-EINVAL);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (strcmp(field_name, "common_timestamp") == 0) {
|
|
|
|
|
*flags |= HIST_FIELD_FL_TIMESTAMP;
|
|
|
|
|
hist_data->enable_timestamps = true;
|
|
|
|
|
if (*flags & HIST_FIELD_FL_TIMESTAMP_USECS)
|
|
|
|
|
hist_data->attrs->ts_in_usecs = true;
|
tracing/histogram: Rename "cpu" to "common_cpu"
commit 1e3bac71c5053c99d438771fc9fa5082ae5d90aa upstream.
Currently the histogram logic allows the user to write "cpu" in as an
event field, and it will record the CPU that the event happened on.
The problem with this is that there's a lot of events that have "cpu"
as a real field, and using "cpu" as the CPU it ran on, makes it
impossible to run histograms on the "cpu" field of events.
For example, if I want to have a histogram on the count of the
workqueue_queue_work event on its cpu field, running:
># echo 'hist:keys=cpu' > events/workqueue/workqueue_queue_work/trigger
Gives a misleading and wrong result.
Change the command to "common_cpu" as no event should have "common_*"
fields as that's a reserved name for fields used by all events. And
this makes sense here as common_cpu would be a field used by all events.
Now we can even do:
># echo 'hist:keys=common_cpu,cpu if cpu < 100' > events/workqueue/workqueue_queue_work/trigger
># cat events/workqueue/workqueue_queue_work/hist
# event histogram
#
# trigger info: hist:keys=common_cpu,cpu:vals=hitcount:sort=hitcount:size=2048 if cpu < 100 [active]
#
{ common_cpu: 0, cpu: 2 } hitcount: 1
{ common_cpu: 0, cpu: 4 } hitcount: 1
{ common_cpu: 7, cpu: 7 } hitcount: 1
{ common_cpu: 0, cpu: 7 } hitcount: 1
{ common_cpu: 0, cpu: 1 } hitcount: 1
{ common_cpu: 0, cpu: 6 } hitcount: 2
{ common_cpu: 0, cpu: 5 } hitcount: 2
{ common_cpu: 1, cpu: 1 } hitcount: 4
{ common_cpu: 6, cpu: 6 } hitcount: 4
{ common_cpu: 5, cpu: 5 } hitcount: 14
{ common_cpu: 4, cpu: 4 } hitcount: 26
{ common_cpu: 0, cpu: 0 } hitcount: 39
{ common_cpu: 2, cpu: 2 } hitcount: 184
Now for backward compatibility, I added a trick. If "cpu" is used, and
the field is not found, it will fall back to "common_cpu" and work as
it did before. This way, it will still work for old programs that use
"cpu" to get the actual CPU, but if the event has a "cpu" as a field, it
will get that event's "cpu" field, which is probably what it wants
anyway.
I updated the tracefs/README to include documentation about both the
common_timestamp and the common_cpu. This way, if that text is present in
the README, then an application can know that common_cpu is supported over
just plain "cpu".
Link: https://lkml.kernel.org/r/20210721110053.26b4f641@oasis.local.home
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Fixes: 8b7622bf94a44 ("tracing: Add cpu field for hist triggers")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-22 00:00:53 +09:00
|
|
|
} else if (strcmp(field_name, "common_cpu") == 0)
|
2018-01-16 11:52:03 +09:00
|
|
|
*flags |= HIST_FIELD_FL_CPU;
|
|
|
|
|
else {
|
2018-01-16 11:51:52 +09:00
|
|
|
field = trace_find_event_field(file->event_call, field_name);
|
|
|
|
|
if (!field || !field->size) {
|
tracing/histogram: Rename "cpu" to "common_cpu"
commit 1e3bac71c5053c99d438771fc9fa5082ae5d90aa upstream.
Currently the histogram logic allows the user to write "cpu" in as an
event field, and it will record the CPU that the event happened on.
The problem with this is that there's a lot of events that have "cpu"
as a real field, and using "cpu" as the CPU it ran on, makes it
impossible to run histograms on the "cpu" field of events.
For example, if I want to have a histogram on the count of the
workqueue_queue_work event on its cpu field, running:
># echo 'hist:keys=cpu' > events/workqueue/workqueue_queue_work/trigger
Gives a misleading and wrong result.
Change the command to "common_cpu" as no event should have "common_*"
fields as that's a reserved name for fields used by all events. And
this makes sense here as common_cpu would be a field used by all events.
Now we can even do:
># echo 'hist:keys=common_cpu,cpu if cpu < 100' > events/workqueue/workqueue_queue_work/trigger
># cat events/workqueue/workqueue_queue_work/hist
# event histogram
#
# trigger info: hist:keys=common_cpu,cpu:vals=hitcount:sort=hitcount:size=2048 if cpu < 100 [active]
#
{ common_cpu: 0, cpu: 2 } hitcount: 1
{ common_cpu: 0, cpu: 4 } hitcount: 1
{ common_cpu: 7, cpu: 7 } hitcount: 1
{ common_cpu: 0, cpu: 7 } hitcount: 1
{ common_cpu: 0, cpu: 1 } hitcount: 1
{ common_cpu: 0, cpu: 6 } hitcount: 2
{ common_cpu: 0, cpu: 5 } hitcount: 2
{ common_cpu: 1, cpu: 1 } hitcount: 4
{ common_cpu: 6, cpu: 6 } hitcount: 4
{ common_cpu: 5, cpu: 5 } hitcount: 14
{ common_cpu: 4, cpu: 4 } hitcount: 26
{ common_cpu: 0, cpu: 0 } hitcount: 39
{ common_cpu: 2, cpu: 2 } hitcount: 184
Now for backward compatibility, I added a trick. If "cpu" is used, and
the field is not found, it will fall back to "common_cpu" and work as
it did before. This way, it will still work for old programs that use
"cpu" to get the actual CPU, but if the event has a "cpu" as a field, it
will get that event's "cpu" field, which is probably what it wants
anyway.
I updated the tracefs/README to include documentation about both the
common_timestamp and the common_cpu. This way, if that text is present in
the README, then an application can know that common_cpu is supported over
just plain "cpu".
Link: https://lkml.kernel.org/r/20210721110053.26b4f641@oasis.local.home
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Fixes: 8b7622bf94a44 ("tracing: Add cpu field for hist triggers")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-22 00:00:53 +09:00
|
|
|
/*
|
|
|
|
|
* For backward compatibility, if field_name
|
|
|
|
|
* was "cpu", then we treat this the same as
|
|
|
|
|
* common_cpu.
|
|
|
|
|
*/
|
|
|
|
|
if (strcmp(field_name, "cpu") == 0) {
|
|
|
|
|
*flags |= HIST_FIELD_FL_CPU;
|
|
|
|
|
} else {
|
|
|
|
|
hist_err(tr, HIST_ERR_FIELD_NOT_FOUND,
|
|
|
|
|
errpos(field_name));
|
|
|
|
|
field = ERR_PTR(-EINVAL);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
2018-01-16 11:51:52 +09:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
kfree(str);
|
|
|
|
|
|
|
|
|
|
return field;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:52:04 +09:00
|
|
|
static struct hist_field *create_alias(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct hist_field *var_ref,
|
|
|
|
|
char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *alias = NULL;
|
|
|
|
|
unsigned long flags = HIST_FIELD_FL_ALIAS | HIST_FIELD_FL_VAR;
|
|
|
|
|
|
|
|
|
|
alias = create_hist_field(hist_data, NULL, flags, var_name);
|
|
|
|
|
if (!alias)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
alias->fn = var_ref->fn;
|
|
|
|
|
alias->operands[0] = var_ref;
|
|
|
|
|
|
|
|
|
|
if (init_var_ref(alias, var_ref, var_ref->system, var_ref->event_name)) {
|
|
|
|
|
destroy_hist_field(alias, 0);
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Make sure variable reference alias has correct var_ref_idx
Original changelog from Steve Rostedt (except last sentence which
explains the problem, and the Fixes: tag):
I performed a three way histogram with the following commands:
echo 'irq_lat u64 lat pid_t pid' > synthetic_events
echo 'wake_lat u64 lat u64 irqlat pid_t pid' >> synthetic_events
echo 'hist:keys=common_pid:irqts=common_timestamp.usecs if function == 0xffffffff81200580' > events/timer/hrtimer_start/trigger
echo 'hist:keys=common_pid:lat=common_timestamp.usecs-$irqts:onmatch(timer.hrtimer_start).irq_lat($lat,pid) if common_flags & 1' > events/sched/sched_waking/trigger
echo 'hist:keys=pid:wakets=common_timestamp.usecs,irqlat=lat' > events/synthetic/irq_lat/trigger
echo 'hist:keys=next_pid:lat=common_timestamp.usecs-$wakets,irqlat=$irqlat:onmatch(synthetic.irq_lat).wake_lat($lat,$irqlat,next_pid)' > events/sched/sched_switch/trigger
echo 1 > events/synthetic/wake_lat/enable
Basically I wanted to see:
hrtimer_start (calling function tick_sched_timer)
Note:
# grep tick_sched_timer /proc/kallsyms
ffffffff81200580 t tick_sched_timer
And save the time of that, and then record sched_waking if it is called
in interrupt context and with the same pid as the hrtimer_start, it
will record the latency between that and the waking event.
I then look at when the task that is woken is scheduled in, and record
the latency between the wakeup and the task running.
At the end, the wake_lat synthetic event will show the wakeup to
scheduled latency, as well as the irq latency in from hritmer_start to
the wakeup. The problem is that I found this:
<idle>-0 [007] d... 190.485261: wake_lat: lat=27 irqlat=190485230 pid=698
<idle>-0 [005] d... 190.485283: wake_lat: lat=40 irqlat=190485239 pid=10
<idle>-0 [002] d... 190.488327: wake_lat: lat=56 irqlat=190488266 pid=335
<idle>-0 [005] d... 190.489330: wake_lat: lat=64 irqlat=190489262 pid=10
<idle>-0 [003] d... 190.490312: wake_lat: lat=43 irqlat=190490265 pid=77
<idle>-0 [005] d... 190.493322: wake_lat: lat=54 irqlat=190493262 pid=10
<idle>-0 [005] d... 190.497305: wake_lat: lat=35 irqlat=190497267 pid=10
<idle>-0 [005] d... 190.501319: wake_lat: lat=50 irqlat=190501264 pid=10
The irqlat seemed quite large! Investigating this further, if I had
enabled the irq_lat synthetic event, I noticed this:
<idle>-0 [002] d.s. 249.429308: irq_lat: lat=164968 pid=335
<idle>-0 [002] d... 249.429369: wake_lat: lat=55 irqlat=249429308 pid=335
Notice that the timestamp of the irq_lat "249.429308" is awfully
similar to the reported irqlat variable. In fact, all instances were
like this. It appeared that:
irqlat=$irqlat
Wasn't assigning the old $irqlat to the new irqlat variable, but
instead was assigning the $irqts to it.
The issue is that assigning the old $irqlat to the new irqlat variable
creates a variable reference alias, but the alias creation code
forgets to make sure the alias uses the same var_ref_idx to access the
reference.
Link: http://lkml.kernel.org/r/1567375321.5282.12.camel@kernel.org
Cc: Linux Trace Devel <linux-trace-devel@vger.kernel.org>
Cc: linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: stable@vger.kernel.org
Fixes: 7e8b88a30b085 ("tracing: Add hist trigger support for variable reference aliases")
Reported-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-09-02 07:02:01 +09:00
|
|
|
alias->var_ref_idx = var_ref->var_ref_idx;
|
|
|
|
|
|
2018-01-16 11:52:04 +09:00
|
|
|
return alias;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:52 +09:00
|
|
|
static struct hist_field *parse_atom(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file, char *str,
|
|
|
|
|
unsigned long *flags, char *var_name)
|
|
|
|
|
{
|
2018-01-16 11:51:56 +09:00
|
|
|
char *s, *ref_system = NULL, *ref_event = NULL, *ref_var = str;
|
2018-01-16 11:51:52 +09:00
|
|
|
struct ftrace_event_field *field = NULL;
|
|
|
|
|
struct hist_field *hist_field = NULL;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
s = strchr(str, '.');
|
|
|
|
|
if (s) {
|
|
|
|
|
s = strchr(++s, '.');
|
|
|
|
|
if (s) {
|
|
|
|
|
ref_system = strsep(&str, ".");
|
|
|
|
|
if (!str) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
ref_event = strsep(&str, ".");
|
|
|
|
|
if (!str) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
ref_var = str;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
s = local_field_var_ref(hist_data, ref_system, ref_event, ref_var);
|
|
|
|
|
if (!s) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_field = parse_var_ref(hist_data, ref_system,
|
|
|
|
|
ref_event, ref_var);
|
2018-01-16 11:51:56 +09:00
|
|
|
if (hist_field) {
|
2018-01-16 11:52:04 +09:00
|
|
|
if (var_name) {
|
|
|
|
|
hist_field = create_alias(hist_data, hist_field, var_name);
|
|
|
|
|
if (!hist_field) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
}
|
2018-01-16 11:51:56 +09:00
|
|
|
return hist_field;
|
|
|
|
|
}
|
|
|
|
|
} else
|
|
|
|
|
str = s;
|
|
|
|
|
|
2018-01-16 11:51:52 +09:00
|
|
|
field = parse_field(hist_data, file, str, flags);
|
|
|
|
|
if (IS_ERR(field)) {
|
|
|
|
|
ret = PTR_ERR(field);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
hist_field = create_hist_field(hist_data, field, *flags, var_name);
|
|
|
|
|
if (!hist_field) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return hist_field;
|
|
|
|
|
out:
|
|
|
|
|
return ERR_PTR(ret);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *str, unsigned long flags,
|
|
|
|
|
char *var_name, unsigned int level);
|
|
|
|
|
|
|
|
|
|
static struct hist_field *parse_unary(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *str, unsigned long flags,
|
|
|
|
|
char *var_name, unsigned int level)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *operand1, *expr = NULL;
|
|
|
|
|
unsigned long operand_flags;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
char *s;
|
|
|
|
|
|
|
|
|
|
/* we support only -(xxx) i.e. explicit parens required */
|
|
|
|
|
|
|
|
|
|
if (level > 3) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(file->tr, HIST_ERR_TOO_MANY_SUBEXPR, errpos(str));
|
2018-01-16 11:51:52 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
str++; /* skip leading '-' */
|
|
|
|
|
|
|
|
|
|
s = strchr(str, '(');
|
|
|
|
|
if (s)
|
|
|
|
|
str++;
|
|
|
|
|
else {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
s = strrchr(str, ')');
|
|
|
|
|
if (s)
|
|
|
|
|
*s = '\0';
|
|
|
|
|
else {
|
|
|
|
|
ret = -EINVAL; /* no closing ')' */
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
flags |= HIST_FIELD_FL_EXPR;
|
|
|
|
|
expr = create_hist_field(hist_data, NULL, flags, var_name);
|
|
|
|
|
if (!expr) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
operand_flags = 0;
|
|
|
|
|
operand1 = parse_expr(hist_data, file, str, operand_flags, NULL, ++level);
|
|
|
|
|
if (IS_ERR(operand1)) {
|
|
|
|
|
ret = PTR_ERR(operand1);
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
2021-07-28 07:55:43 +09:00
|
|
|
if (operand1->flags & HIST_FIELD_FL_STRING) {
|
|
|
|
|
/* String type can not be the operand of unary operator. */
|
|
|
|
|
hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(str));
|
|
|
|
|
destroy_hist_field(operand1, 0);
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
2018-01-16 11:51:52 +09:00
|
|
|
|
|
|
|
|
expr->flags |= operand1->flags &
|
|
|
|
|
(HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
|
|
|
|
|
expr->fn = hist_field_unary_minus;
|
|
|
|
|
expr->operands[0] = operand1;
|
|
|
|
|
expr->operator = FIELD_OP_UNARY_MINUS;
|
|
|
|
|
expr->name = expr_str(expr, 0);
|
2018-01-16 11:51:55 +09:00
|
|
|
expr->type = kstrdup(operand1->type, GFP_KERNEL);
|
|
|
|
|
if (!expr->type) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
2018-01-16 11:51:52 +09:00
|
|
|
|
|
|
|
|
return expr;
|
|
|
|
|
free:
|
|
|
|
|
destroy_hist_field(expr, 0);
|
|
|
|
|
return ERR_PTR(ret);
|
|
|
|
|
}
|
|
|
|
|
|
2019-04-02 11:30:22 +09:00
|
|
|
static int check_expr_operands(struct trace_array *tr,
|
|
|
|
|
struct hist_field *operand1,
|
2018-01-16 11:51:52 +09:00
|
|
|
struct hist_field *operand2)
|
|
|
|
|
{
|
|
|
|
|
unsigned long operand1_flags = operand1->flags;
|
|
|
|
|
unsigned long operand2_flags = operand2->flags;
|
|
|
|
|
|
2018-01-16 11:52:04 +09:00
|
|
|
if ((operand1_flags & HIST_FIELD_FL_VAR_REF) ||
|
|
|
|
|
(operand1_flags & HIST_FIELD_FL_ALIAS)) {
|
|
|
|
|
struct hist_field *var;
|
|
|
|
|
|
|
|
|
|
var = find_var_field(operand1->var.hist_data, operand1->name);
|
|
|
|
|
if (!var)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
operand1_flags = var->flags;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if ((operand2_flags & HIST_FIELD_FL_VAR_REF) ||
|
|
|
|
|
(operand2_flags & HIST_FIELD_FL_ALIAS)) {
|
|
|
|
|
struct hist_field *var;
|
|
|
|
|
|
|
|
|
|
var = find_var_field(operand2->var.hist_data, operand2->name);
|
|
|
|
|
if (!var)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
operand2_flags = var->flags;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:52 +09:00
|
|
|
if ((operand1_flags & HIST_FIELD_FL_TIMESTAMP_USECS) !=
|
2018-01-16 11:52:05 +09:00
|
|
|
(operand2_flags & HIST_FIELD_FL_TIMESTAMP_USECS)) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_TIMESTAMP_MISMATCH, 0);
|
2018-01-16 11:51:52 +09:00
|
|
|
return -EINVAL;
|
2018-01-16 11:52:05 +09:00
|
|
|
}
|
2018-01-16 11:51:52 +09:00
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *str, unsigned long flags,
|
|
|
|
|
char *var_name, unsigned int level)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *operand1 = NULL, *operand2 = NULL, *expr = NULL;
|
|
|
|
|
unsigned long operand_flags;
|
|
|
|
|
int field_op, ret = -EINVAL;
|
|
|
|
|
char *sep, *operand1_str;
|
|
|
|
|
|
2018-01-16 11:52:05 +09:00
|
|
|
if (level > 3) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(file->tr, HIST_ERR_TOO_MANY_SUBEXPR, errpos(str));
|
2018-01-16 11:51:52 +09:00
|
|
|
return ERR_PTR(-EINVAL);
|
2018-01-16 11:52:05 +09:00
|
|
|
}
|
2018-01-16 11:51:52 +09:00
|
|
|
|
|
|
|
|
field_op = contains_operator(str);
|
|
|
|
|
|
|
|
|
|
if (field_op == FIELD_OP_NONE)
|
|
|
|
|
return parse_atom(hist_data, file, str, &flags, var_name);
|
|
|
|
|
|
|
|
|
|
if (field_op == FIELD_OP_UNARY_MINUS)
|
|
|
|
|
return parse_unary(hist_data, file, str, flags, var_name, ++level);
|
|
|
|
|
|
|
|
|
|
switch (field_op) {
|
|
|
|
|
case FIELD_OP_MINUS:
|
|
|
|
|
sep = "-";
|
|
|
|
|
break;
|
|
|
|
|
case FIELD_OP_PLUS:
|
|
|
|
|
sep = "+";
|
|
|
|
|
break;
|
|
|
|
|
default:
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
operand1_str = strsep(&str, sep);
|
|
|
|
|
if (!operand1_str || !str)
|
|
|
|
|
goto free;
|
|
|
|
|
|
|
|
|
|
operand_flags = 0;
|
|
|
|
|
operand1 = parse_atom(hist_data, file, operand1_str,
|
|
|
|
|
&operand_flags, NULL);
|
|
|
|
|
if (IS_ERR(operand1)) {
|
|
|
|
|
ret = PTR_ERR(operand1);
|
|
|
|
|
operand1 = NULL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
2021-07-28 07:55:43 +09:00
|
|
|
if (operand1->flags & HIST_FIELD_FL_STRING) {
|
|
|
|
|
hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(operand1_str));
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
2018-01-16 11:51:52 +09:00
|
|
|
|
|
|
|
|
/* rest of string could be another expression e.g. b+c in a+b+c */
|
|
|
|
|
operand_flags = 0;
|
|
|
|
|
operand2 = parse_expr(hist_data, file, str, operand_flags, NULL, ++level);
|
|
|
|
|
if (IS_ERR(operand2)) {
|
|
|
|
|
ret = PTR_ERR(operand2);
|
|
|
|
|
operand2 = NULL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
2021-07-28 07:55:43 +09:00
|
|
|
if (operand2->flags & HIST_FIELD_FL_STRING) {
|
|
|
|
|
hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(str));
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
2018-01-16 11:51:52 +09:00
|
|
|
|
2019-04-02 11:30:22 +09:00
|
|
|
ret = check_expr_operands(file->tr, operand1, operand2);
|
2018-01-16 11:51:52 +09:00
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
|
|
|
|
|
|
|
|
|
flags |= HIST_FIELD_FL_EXPR;
|
|
|
|
|
|
|
|
|
|
flags |= operand1->flags &
|
|
|
|
|
(HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
|
|
|
|
|
|
|
|
|
|
expr = create_hist_field(hist_data, NULL, flags, var_name);
|
|
|
|
|
if (!expr) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
operand1->read_once = true;
|
|
|
|
|
operand2->read_once = true;
|
|
|
|
|
|
2018-01-16 11:51:52 +09:00
|
|
|
expr->operands[0] = operand1;
|
|
|
|
|
expr->operands[1] = operand2;
|
tracing / histogram: Give calculation hist_fields a size
commit 2c05caa7ba8803209769b9e4fe02c38d77ae88d0 upstream.
When working on my user space applications, I found a bug in the synthetic
event code where the automated synthetic event field was not matching the
event field calculation it was attached to. Looking deeper into it, it was
because the calculation hist_field was not given a size.
The synthetic event fields are matched to their hist_fields either by
having the field have an identical string type, or if that does not match,
then the size and signed values are used to match the fields.
The problem arose when I tried to match a calculation where the fields
were "unsigned int". My tool created a synthetic event of type "u32". But
it failed to match. The string was:
diff=field1-field2:onmatch(event).trace(synth,$diff)
Adding debugging into the kernel, I found that the size of "diff" was 0.
And since it was given "unsigned int" as a type, the histogram fallback
code used size and signed. The signed matched, but the size of u32 (4) did
not match zero, and the event failed to be created.
This can be worse if the field you want to match is not one of the
acceptable fields for a synthetic event. As event fields can have any type
that is supported in Linux, this can cause an issue. For example, if a
type is an enum. Then there's no way to use that with any calculations.
Have the calculation field simply take on the size of what it is
calculating.
Link: https://lkml.kernel.org/r/20210730171951.59c7743f@oasis.local.home
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Fixes: 100719dcef447 ("tracing: Add simple expression support to hist triggers")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-31 06:19:51 +09:00
|
|
|
|
|
|
|
|
/* The operand sizes should be the same, so just pick one */
|
|
|
|
|
expr->size = operand1->size;
|
|
|
|
|
|
2018-01-16 11:51:52 +09:00
|
|
|
expr->operator = field_op;
|
|
|
|
|
expr->name = expr_str(expr, 0);
|
2018-01-16 11:51:55 +09:00
|
|
|
expr->type = kstrdup(operand1->type, GFP_KERNEL);
|
|
|
|
|
if (!expr->type) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
2018-01-16 11:51:52 +09:00
|
|
|
|
|
|
|
|
switch (field_op) {
|
|
|
|
|
case FIELD_OP_MINUS:
|
|
|
|
|
expr->fn = hist_field_minus;
|
|
|
|
|
break;
|
|
|
|
|
case FIELD_OP_PLUS:
|
|
|
|
|
expr->fn = hist_field_plus;
|
|
|
|
|
break;
|
|
|
|
|
default:
|
2018-03-23 20:37:36 +09:00
|
|
|
ret = -EINVAL;
|
2018-01-16 11:51:52 +09:00
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return expr;
|
|
|
|
|
free:
|
|
|
|
|
destroy_hist_field(operand1, 0);
|
|
|
|
|
destroy_hist_field(operand2, 0);
|
|
|
|
|
destroy_hist_field(expr, 0);
|
|
|
|
|
|
|
|
|
|
return ERR_PTR(ret);
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
static char *find_trigger_filter(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
struct event_trigger_data *test;
|
|
|
|
|
|
2019-12-20 11:31:43 +09:00
|
|
|
lockdep_assert_held(&event_mutex);
|
|
|
|
|
|
|
|
|
|
list_for_each_entry(test, &file->triggers, list) {
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
|
|
|
if (test->private_data == hist_data)
|
|
|
|
|
return test->filter_str;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct event_command trigger_hist_cmd;
|
|
|
|
|
static int event_hist_trigger_func(struct event_command *cmd_ops,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *glob, char *cmd, char *param);
|
|
|
|
|
|
|
|
|
|
static bool compatible_keys(struct hist_trigger_data *target_hist_data,
|
|
|
|
|
struct hist_trigger_data *hist_data,
|
|
|
|
|
unsigned int n_keys)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *target_hist_field, *hist_field;
|
|
|
|
|
unsigned int n, i, j;
|
|
|
|
|
|
|
|
|
|
if (hist_data->n_fields - hist_data->n_vals != n_keys)
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
i = hist_data->n_vals;
|
|
|
|
|
j = target_hist_data->n_vals;
|
|
|
|
|
|
|
|
|
|
for (n = 0; n < n_keys; n++) {
|
|
|
|
|
hist_field = hist_data->fields[i + n];
|
|
|
|
|
target_hist_field = target_hist_data->fields[j + n];
|
|
|
|
|
|
|
|
|
|
if (strcmp(hist_field->type, target_hist_field->type) != 0)
|
|
|
|
|
return false;
|
|
|
|
|
if (hist_field->size != target_hist_field->size)
|
|
|
|
|
return false;
|
|
|
|
|
if (hist_field->is_signed != target_hist_field->is_signed)
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_trigger_data *
|
|
|
|
|
find_compatible_hist(struct hist_trigger_data *target_hist_data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
|
|
|
|
struct event_trigger_data *test;
|
|
|
|
|
unsigned int n_keys;
|
|
|
|
|
|
2019-12-20 11:31:43 +09:00
|
|
|
lockdep_assert_held(&event_mutex);
|
|
|
|
|
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
n_keys = target_hist_data->n_fields - target_hist_data->n_vals;
|
|
|
|
|
|
2019-12-20 11:31:43 +09:00
|
|
|
list_for_each_entry(test, &file->triggers, list) {
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
|
|
|
hist_data = test->private_data;
|
|
|
|
|
|
|
|
|
|
if (compatible_keys(target_hist_data, hist_data, n_keys))
|
|
|
|
|
return hist_data;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct trace_event_file *event_file(struct trace_array *tr,
|
|
|
|
|
char *system, char *event_name)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_file *file;
|
|
|
|
|
|
2018-05-11 01:42:10 +09:00
|
|
|
file = __find_event_file(tr, system, event_name);
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
if (!file)
|
|
|
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
|
|
|
|
|
|
return file;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *
|
|
|
|
|
find_synthetic_field_var(struct hist_trigger_data *target_hist_data,
|
|
|
|
|
char *system, char *event_name, char *field_name)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *event_var;
|
|
|
|
|
char *synthetic_name;
|
|
|
|
|
|
|
|
|
|
synthetic_name = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
|
|
|
|
|
if (!synthetic_name)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
strcpy(synthetic_name, "synthetic_");
|
|
|
|
|
strcat(synthetic_name, field_name);
|
|
|
|
|
|
|
|
|
|
event_var = find_event_var(target_hist_data, system, event_name, synthetic_name);
|
|
|
|
|
|
|
|
|
|
kfree(synthetic_name);
|
|
|
|
|
|
|
|
|
|
return event_var;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* create_field_var_hist - Automatically create a histogram and var for a field
|
|
|
|
|
* @target_hist_data: The target hist trigger
|
|
|
|
|
* @subsys_name: Optional subsystem name
|
|
|
|
|
* @event_name: Optional event name
|
|
|
|
|
* @field_name: The name of the field (and the resulting variable)
|
|
|
|
|
*
|
|
|
|
|
* Hist trigger actions fetch data from variables, not directly from
|
|
|
|
|
* events. However, for convenience, users are allowed to directly
|
|
|
|
|
* specify an event field in an action, which will be automatically
|
|
|
|
|
* converted into a variable on their behalf.
|
|
|
|
|
|
|
|
|
|
* If a user specifies a field on an event that isn't the event the
|
|
|
|
|
* histogram currently being defined (the target event histogram), the
|
|
|
|
|
* only way that can be accomplished is if a new hist trigger is
|
|
|
|
|
* created and the field variable defined on that.
|
|
|
|
|
*
|
|
|
|
|
* This function creates a new histogram compatible with the target
|
|
|
|
|
* event (meaning a histogram with the same key as the target
|
|
|
|
|
* histogram), and creates a variable for the specified field, but
|
|
|
|
|
* with 'synthetic_' prepended to the variable name in order to avoid
|
|
|
|
|
* collision with normal field variables.
|
|
|
|
|
*
|
|
|
|
|
* Return: The variable created for the field.
|
|
|
|
|
*/
|
2018-01-16 11:52:00 +09:00
|
|
|
static struct hist_field *
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
create_field_var_hist(struct hist_trigger_data *target_hist_data,
|
|
|
|
|
char *subsys_name, char *event_name, char *field_name)
|
|
|
|
|
{
|
|
|
|
|
struct trace_array *tr = target_hist_data->event_file->tr;
|
|
|
|
|
struct hist_field *event_var = ERR_PTR(-EINVAL);
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
|
|
|
|
unsigned int i, n, first = true;
|
|
|
|
|
struct field_var_hist *var_hist;
|
|
|
|
|
struct trace_event_file *file;
|
|
|
|
|
struct hist_field *key_field;
|
|
|
|
|
char *saved_filter;
|
|
|
|
|
char *cmd;
|
|
|
|
|
int ret;
|
|
|
|
|
|
2018-01-16 11:52:05 +09:00
|
|
|
if (target_hist_data->n_field_var_hists >= SYNTH_FIELDS_MAX) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_TOO_MANY_FIELD_VARS, errpos(field_name));
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
return ERR_PTR(-EINVAL);
|
2018-01-16 11:52:05 +09:00
|
|
|
}
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
|
|
|
|
|
file = event_file(tr, subsys_name, event_name);
|
|
|
|
|
|
|
|
|
|
if (IS_ERR(file)) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_EVENT_FILE_NOT_FOUND, errpos(field_name));
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
ret = PTR_ERR(file);
|
|
|
|
|
return ERR_PTR(ret);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Look for a histogram compatible with target. We'll use the
|
|
|
|
|
* found histogram specification to create a new matching
|
|
|
|
|
* histogram with our variable on it. target_hist_data is not
|
|
|
|
|
* yet a registered histogram so we can't use that.
|
|
|
|
|
*/
|
|
|
|
|
hist_data = find_compatible_hist(target_hist_data, file);
|
2018-01-16 11:52:05 +09:00
|
|
|
if (!hist_data) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_HIST_NOT_FOUND, errpos(field_name));
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
return ERR_PTR(-EINVAL);
|
2018-01-16 11:52:05 +09:00
|
|
|
}
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
|
|
|
|
|
/* See if a synthetic field variable has already been created */
|
|
|
|
|
event_var = find_synthetic_field_var(target_hist_data, subsys_name,
|
|
|
|
|
event_name, field_name);
|
|
|
|
|
if (!IS_ERR_OR_NULL(event_var))
|
|
|
|
|
return event_var;
|
|
|
|
|
|
|
|
|
|
var_hist = kzalloc(sizeof(*var_hist), GFP_KERNEL);
|
|
|
|
|
if (!var_hist)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
cmd = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
|
|
|
|
|
if (!cmd) {
|
|
|
|
|
kfree(var_hist);
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Use the same keys as the compatible histogram */
|
|
|
|
|
strcat(cmd, "keys=");
|
|
|
|
|
|
|
|
|
|
for_each_hist_key_field(i, hist_data) {
|
|
|
|
|
key_field = hist_data->fields[i];
|
|
|
|
|
if (!first)
|
|
|
|
|
strcat(cmd, ",");
|
|
|
|
|
strcat(cmd, key_field->field->name);
|
|
|
|
|
first = false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Create the synthetic field variable specification */
|
|
|
|
|
strcat(cmd, ":synthetic_");
|
|
|
|
|
strcat(cmd, field_name);
|
|
|
|
|
strcat(cmd, "=");
|
|
|
|
|
strcat(cmd, field_name);
|
|
|
|
|
|
|
|
|
|
/* Use the same filter as the compatible histogram */
|
|
|
|
|
saved_filter = find_trigger_filter(hist_data, file);
|
|
|
|
|
if (saved_filter) {
|
|
|
|
|
strcat(cmd, " if ");
|
|
|
|
|
strcat(cmd, saved_filter);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
var_hist->cmd = kstrdup(cmd, GFP_KERNEL);
|
|
|
|
|
if (!var_hist->cmd) {
|
|
|
|
|
kfree(cmd);
|
|
|
|
|
kfree(var_hist);
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Save the compatible histogram information */
|
|
|
|
|
var_hist->hist_data = hist_data;
|
|
|
|
|
|
|
|
|
|
/* Create the new histogram with our variable */
|
|
|
|
|
ret = event_hist_trigger_func(&trigger_hist_cmd, file,
|
|
|
|
|
"", "hist", cmd);
|
|
|
|
|
if (ret) {
|
|
|
|
|
kfree(cmd);
|
|
|
|
|
kfree(var_hist->cmd);
|
|
|
|
|
kfree(var_hist);
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_HIST_CREATE_FAIL, errpos(field_name));
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
return ERR_PTR(ret);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
kfree(cmd);
|
|
|
|
|
|
|
|
|
|
/* If we can't find the variable, something went wrong */
|
|
|
|
|
event_var = find_synthetic_field_var(target_hist_data, subsys_name,
|
|
|
|
|
event_name, field_name);
|
|
|
|
|
if (IS_ERR_OR_NULL(event_var)) {
|
|
|
|
|
kfree(var_hist->cmd);
|
|
|
|
|
kfree(var_hist);
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_SYNTH_VAR_NOT_FOUND, errpos(field_name));
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
n = target_hist_data->n_field_var_hists;
|
|
|
|
|
target_hist_data->field_var_hists[n] = var_hist;
|
|
|
|
|
target_hist_data->n_field_var_hists++;
|
|
|
|
|
|
|
|
|
|
return event_var;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:52:00 +09:00
|
|
|
static struct hist_field *
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
find_target_event_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
char *subsys_name, char *event_name, char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_file *file = hist_data->event_file;
|
|
|
|
|
struct hist_field *hist_field = NULL;
|
|
|
|
|
|
|
|
|
|
if (subsys_name) {
|
|
|
|
|
struct trace_event_call *call;
|
|
|
|
|
|
|
|
|
|
if (!event_name)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
call = file->event_call;
|
|
|
|
|
|
|
|
|
|
if (strcmp(subsys_name, call->class->system) != 0)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
if (strcmp(event_name, trace_event_name(call)) != 0)
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
hist_field = find_var_field(hist_data, var_name);
|
|
|
|
|
|
|
|
|
|
return hist_field;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline void __update_field_vars(struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *rec,
|
|
|
|
|
struct field_var **field_vars,
|
|
|
|
|
unsigned int n_field_vars,
|
|
|
|
|
unsigned int field_var_str_start)
|
|
|
|
|
{
|
|
|
|
|
struct hist_elt_data *elt_data = elt->private_data;
|
|
|
|
|
unsigned int i, j, var_idx;
|
|
|
|
|
u64 var_val;
|
|
|
|
|
|
|
|
|
|
for (i = 0, j = field_var_str_start; i < n_field_vars; i++) {
|
|
|
|
|
struct field_var *field_var = field_vars[i];
|
|
|
|
|
struct hist_field *var = field_var->var;
|
|
|
|
|
struct hist_field *val = field_var->val;
|
|
|
|
|
|
|
|
|
|
var_val = val->fn(val, elt, rbe, rec);
|
|
|
|
|
var_idx = var->var.idx;
|
|
|
|
|
|
|
|
|
|
if (val->flags & HIST_FIELD_FL_STRING) {
|
|
|
|
|
char *str = elt_data->field_var_str[j++];
|
|
|
|
|
char *val_str = (char *)(uintptr_t)var_val;
|
|
|
|
|
|
2018-03-29 05:10:56 +09:00
|
|
|
strscpy(str, val_str, STR_VAR_LEN_MAX);
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
var_val = (u64)(uintptr_t)str;
|
|
|
|
|
}
|
|
|
|
|
tracing_map_set_var(elt, var_idx, var_val);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void update_field_vars(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *rec)
|
|
|
|
|
{
|
|
|
|
|
__update_field_vars(elt, rbe, rec, hist_data->field_vars,
|
|
|
|
|
hist_data->n_field_vars, 0);
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
static void save_track_data_vars(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt, void *rec,
|
|
|
|
|
struct ring_buffer_event *rbe, void *key,
|
|
|
|
|
struct action_data *data, u64 *var_ref_vals)
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
{
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
__update_field_vars(elt, rbe, rec, hist_data->save_vars,
|
|
|
|
|
hist_data->n_save_vars, hist_data->n_field_var_str);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
static struct hist_field *create_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *name, int size, const char *type)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *var;
|
|
|
|
|
int idx;
|
|
|
|
|
|
|
|
|
|
if (find_var(hist_data, file, name) && !hist_data->remove) {
|
|
|
|
|
var = ERR_PTR(-EINVAL);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
var = kzalloc(sizeof(struct hist_field), GFP_KERNEL);
|
|
|
|
|
if (!var) {
|
|
|
|
|
var = ERR_PTR(-ENOMEM);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
idx = tracing_map_add_var(hist_data->map);
|
|
|
|
|
if (idx < 0) {
|
|
|
|
|
kfree(var);
|
|
|
|
|
var = ERR_PTR(-EINVAL);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2020-04-22 15:15:06 +09:00
|
|
|
var->ref = 1;
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
var->flags = HIST_FIELD_FL_VAR;
|
|
|
|
|
var->var.idx = idx;
|
|
|
|
|
var->var.hist_data = var->hist_data = hist_data;
|
|
|
|
|
var->size = size;
|
|
|
|
|
var->var.name = kstrdup(name, GFP_KERNEL);
|
|
|
|
|
var->type = kstrdup(type, GFP_KERNEL);
|
|
|
|
|
if (!var->var.name || !var->type) {
|
|
|
|
|
kfree(var->var.name);
|
|
|
|
|
kfree(var->type);
|
|
|
|
|
kfree(var);
|
|
|
|
|
var = ERR_PTR(-ENOMEM);
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
return var;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct field_var *create_field_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *field_name)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *val = NULL, *var = NULL;
|
|
|
|
|
unsigned long flags = HIST_FIELD_FL_VAR;
|
2019-04-02 11:30:22 +09:00
|
|
|
struct trace_array *tr = file->tr;
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
struct field_var *field_var;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
if (hist_data->n_field_vars >= SYNTH_FIELDS_MAX) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_TOO_MANY_FIELD_VARS, errpos(field_name));
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
val = parse_atom(hist_data, file, field_name, &flags, NULL);
|
|
|
|
|
if (IS_ERR(val)) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_FIELD_VAR_PARSE_FAIL, errpos(field_name));
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
ret = PTR_ERR(val);
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
var = create_var(hist_data, file, field_name, val->size, val->type);
|
|
|
|
|
if (IS_ERR(var)) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_VAR_CREATE_FIND_FAIL, errpos(field_name));
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
kfree(val);
|
|
|
|
|
ret = PTR_ERR(var);
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
field_var = kzalloc(sizeof(struct field_var), GFP_KERNEL);
|
|
|
|
|
if (!field_var) {
|
|
|
|
|
kfree(val);
|
|
|
|
|
kfree(var);
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
field_var->var = var;
|
|
|
|
|
field_var->val = val;
|
|
|
|
|
out:
|
|
|
|
|
return field_var;
|
|
|
|
|
err:
|
|
|
|
|
field_var = ERR_PTR(ret);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* create_target_field_var - Automatically create a variable for a field
|
|
|
|
|
* @target_hist_data: The target hist trigger
|
|
|
|
|
* @subsys_name: Optional subsystem name
|
|
|
|
|
* @event_name: Optional event name
|
|
|
|
|
* @var_name: The name of the field (and the resulting variable)
|
|
|
|
|
*
|
|
|
|
|
* Hist trigger actions fetch data from variables, not directly from
|
|
|
|
|
* events. However, for convenience, users are allowed to directly
|
|
|
|
|
* specify an event field in an action, which will be automatically
|
|
|
|
|
* converted into a variable on their behalf.
|
|
|
|
|
|
|
|
|
|
* This function creates a field variable with the name var_name on
|
|
|
|
|
* the hist trigger currently being defined on the target event. If
|
|
|
|
|
* subsys_name and event_name are specified, this function simply
|
|
|
|
|
* verifies that they do in fact match the target event subsystem and
|
|
|
|
|
* event name.
|
|
|
|
|
*
|
|
|
|
|
* Return: The variable created for the field.
|
|
|
|
|
*/
|
2018-01-16 11:52:00 +09:00
|
|
|
static struct field_var *
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
create_target_field_var(struct hist_trigger_data *target_hist_data,
|
|
|
|
|
char *subsys_name, char *event_name, char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_file *file = target_hist_data->event_file;
|
|
|
|
|
|
|
|
|
|
if (subsys_name) {
|
|
|
|
|
struct trace_event_call *call;
|
|
|
|
|
|
|
|
|
|
if (!event_name)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
call = file->event_call;
|
|
|
|
|
|
|
|
|
|
if (strcmp(subsys_name, call->class->system) != 0)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
if (strcmp(event_name, trace_event_name(call)) != 0)
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return create_field_var(target_hist_data, file, var_name);
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
static bool check_track_val_max(u64 track_val, u64 var_val)
|
|
|
|
|
{
|
|
|
|
|
if (var_val <= track_val)
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:48 +09:00
|
|
|
static bool check_track_val_changed(u64 track_val, u64 var_val)
|
|
|
|
|
{
|
|
|
|
|
if (var_val == track_val)
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
static u64 get_track_val(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct action_data *data)
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
{
|
2019-02-14 08:42:44 +09:00
|
|
|
unsigned int track_var_idx = data->track_data.track_var->var.idx;
|
|
|
|
|
u64 track_val;
|
|
|
|
|
|
|
|
|
|
track_val = tracing_map_read_var(elt, track_var_idx);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
return track_val;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void save_track_val(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct action_data *data, u64 var_val)
|
|
|
|
|
{
|
|
|
|
|
unsigned int track_var_idx = data->track_data.track_var->var.idx;
|
|
|
|
|
|
|
|
|
|
tracing_map_set_var(elt, track_var_idx, var_val);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void save_track_data(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt, void *rec,
|
|
|
|
|
struct ring_buffer_event *rbe, void *key,
|
|
|
|
|
struct action_data *data, u64 *var_ref_vals)
|
|
|
|
|
{
|
|
|
|
|
if (data->track_data.save_data)
|
|
|
|
|
data->track_data.save_data(hist_data, elt, rec, rbe, key, data, var_ref_vals);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool check_track_val(struct tracing_map_elt *elt,
|
|
|
|
|
struct action_data *data,
|
|
|
|
|
u64 var_val)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
|
|
|
|
u64 track_val;
|
|
|
|
|
|
|
|
|
|
hist_data = data->track_data.track_var->hist_data;
|
|
|
|
|
track_val = get_track_val(hist_data, elt, data);
|
|
|
|
|
|
|
|
|
|
return data->track_data.check_val(track_val, var_val);
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:46 +09:00
|
|
|
#ifdef CONFIG_TRACER_SNAPSHOT
|
|
|
|
|
static bool cond_snapshot_update(struct trace_array *tr, void *cond_data)
|
|
|
|
|
{
|
|
|
|
|
/* called with tr->max_lock held */
|
|
|
|
|
struct track_data *track_data = tr->cond_snapshot->cond_data;
|
|
|
|
|
struct hist_elt_data *elt_data, *track_elt_data;
|
|
|
|
|
struct snapshot_context *context = cond_data;
|
tracing: Add a check_val() check before updating cond_snapshot() track_val
Without this check a snapshot is taken whenever a bucket's max is hit,
rather than only when the global max is hit, as it should be.
Before:
In this example, we do a first run of the workload (cyclictest),
examine the output, note the max ('triggering value') (347), then do
a second run and note the max again.
In this case, the max in the second run (39) is below the max in the
first run, but since we haven't cleared the histogram, the first max
is still in the histogram and is higher than any other max, so it
should still be the max for the snapshot. It isn't however - the
value should still be 347 after the second run.
# echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="cyclictest"' >> /sys/kernel/debug/tracing/events/sched/sched_waking/trigger
# echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:onmax($wakeup_lat).save(next_prio,next_comm,prev_pid,prev_prio,prev_comm):onmax($wakeup_lat).snapshot() if next_comm=="cyclictest"' >> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
# cyclictest -p 80 -n -s -t 2 -D 2
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 2143 } hitcount: 199
max: 44 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/4
{ next_pid: 2145 } hitcount: 1325
max: 38 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/2
{ next_pid: 2144 } hitcount: 1982
max: 347 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
Snapshot taken (see tracing/snapshot). Details:
triggering value { onmax($wakeup_lat) }: 347
triggered by event with key: { next_pid: 2144 }
# cyclictest -p 80 -n -s -t 2 -D 2
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 2143 } hitcount: 199
max: 44 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/4
{ next_pid: 2148 } hitcount: 199
max: 16 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/1
{ next_pid: 2145 } hitcount: 1325
max: 38 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/2
{ next_pid: 2150 } hitcount: 1326
max: 39 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/4
{ next_pid: 2144 } hitcount: 1982
max: 347 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
{ next_pid: 2149 } hitcount: 1983
max: 130 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/0
Snapshot taken (see tracing/snapshot). Details:
triggering value { onmax($wakeup_lat) }: 39
triggered by event with key: { next_pid: 2150 }
After:
In this example, we do a first run of the workload (cyclictest),
examine the output, note the max ('triggering value') (375), then do
a second run and note the max again.
In this case, the max in the second run is still 375, the highest in
any bucket, as it should be.
# cyclictest -p 80 -n -s -t 2 -D 2
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 2072 } hitcount: 200
max: 28 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/5
{ next_pid: 2074 } hitcount: 1323
max: 375 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/2
{ next_pid: 2073 } hitcount: 1980
max: 153 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
Snapshot taken (see tracing/snapshot). Details:
triggering value { onmax($wakeup_lat) }: 375
triggered by event with key: { next_pid: 2074 }
# cyclictest -p 80 -n -s -t 2 -D 2
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 2101 } hitcount: 199
max: 49 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
{ next_pid: 2072 } hitcount: 200
max: 28 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/5
{ next_pid: 2074 } hitcount: 1323
max: 375 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/2
{ next_pid: 2103 } hitcount: 1325
max: 74 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/4
{ next_pid: 2073 } hitcount: 1980
max: 153 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
{ next_pid: 2102 } hitcount: 1981
max: 84 next_prio: 19 next_comm: cyclictest
prev_pid: 12 prev_prio: 120 prev_comm: kworker/0:1
Snapshot taken (see tracing/snapshot). Details:
triggering value { onmax($wakeup_lat) }: 375
triggered by event with key: { next_pid: 2074 }
Link: http://lkml.kernel.org/r/95958351329f129c07504b4d1769c47a97b70d65.1555597045.git.tom.zanussi@linux.intel.com
Cc: stable@vger.kernel.org
Fixes: a3785b7eca8fd ("tracing: Add hist trigger snapshot() action")
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-04-19 00:18:52 +09:00
|
|
|
struct action_data *action;
|
2019-02-14 08:42:46 +09:00
|
|
|
u64 track_val;
|
|
|
|
|
|
|
|
|
|
if (!track_data)
|
|
|
|
|
return false;
|
|
|
|
|
|
tracing: Add a check_val() check before updating cond_snapshot() track_val
Without this check a snapshot is taken whenever a bucket's max is hit,
rather than only when the global max is hit, as it should be.
Before:
In this example, we do a first run of the workload (cyclictest),
examine the output, note the max ('triggering value') (347), then do
a second run and note the max again.
In this case, the max in the second run (39) is below the max in the
first run, but since we haven't cleared the histogram, the first max
is still in the histogram and is higher than any other max, so it
should still be the max for the snapshot. It isn't however - the
value should still be 347 after the second run.
# echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="cyclictest"' >> /sys/kernel/debug/tracing/events/sched/sched_waking/trigger
# echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:onmax($wakeup_lat).save(next_prio,next_comm,prev_pid,prev_prio,prev_comm):onmax($wakeup_lat).snapshot() if next_comm=="cyclictest"' >> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
# cyclictest -p 80 -n -s -t 2 -D 2
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 2143 } hitcount: 199
max: 44 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/4
{ next_pid: 2145 } hitcount: 1325
max: 38 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/2
{ next_pid: 2144 } hitcount: 1982
max: 347 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
Snapshot taken (see tracing/snapshot). Details:
triggering value { onmax($wakeup_lat) }: 347
triggered by event with key: { next_pid: 2144 }
# cyclictest -p 80 -n -s -t 2 -D 2
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 2143 } hitcount: 199
max: 44 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/4
{ next_pid: 2148 } hitcount: 199
max: 16 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/1
{ next_pid: 2145 } hitcount: 1325
max: 38 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/2
{ next_pid: 2150 } hitcount: 1326
max: 39 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/4
{ next_pid: 2144 } hitcount: 1982
max: 347 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
{ next_pid: 2149 } hitcount: 1983
max: 130 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/0
Snapshot taken (see tracing/snapshot). Details:
triggering value { onmax($wakeup_lat) }: 39
triggered by event with key: { next_pid: 2150 }
After:
In this example, we do a first run of the workload (cyclictest),
examine the output, note the max ('triggering value') (375), then do
a second run and note the max again.
In this case, the max in the second run is still 375, the highest in
any bucket, as it should be.
# cyclictest -p 80 -n -s -t 2 -D 2
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 2072 } hitcount: 200
max: 28 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/5
{ next_pid: 2074 } hitcount: 1323
max: 375 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/2
{ next_pid: 2073 } hitcount: 1980
max: 153 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
Snapshot taken (see tracing/snapshot). Details:
triggering value { onmax($wakeup_lat) }: 375
triggered by event with key: { next_pid: 2074 }
# cyclictest -p 80 -n -s -t 2 -D 2
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 2101 } hitcount: 199
max: 49 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
{ next_pid: 2072 } hitcount: 200
max: 28 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/5
{ next_pid: 2074 } hitcount: 1323
max: 375 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/2
{ next_pid: 2103 } hitcount: 1325
max: 74 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/4
{ next_pid: 2073 } hitcount: 1980
max: 153 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
{ next_pid: 2102 } hitcount: 1981
max: 84 next_prio: 19 next_comm: cyclictest
prev_pid: 12 prev_prio: 120 prev_comm: kworker/0:1
Snapshot taken (see tracing/snapshot). Details:
triggering value { onmax($wakeup_lat) }: 375
triggered by event with key: { next_pid: 2074 }
Link: http://lkml.kernel.org/r/95958351329f129c07504b4d1769c47a97b70d65.1555597045.git.tom.zanussi@linux.intel.com
Cc: stable@vger.kernel.org
Fixes: a3785b7eca8fd ("tracing: Add hist trigger snapshot() action")
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-04-19 00:18:52 +09:00
|
|
|
action = track_data->action_data;
|
|
|
|
|
|
2019-02-14 08:42:46 +09:00
|
|
|
track_val = get_track_val(track_data->hist_data, context->elt,
|
|
|
|
|
track_data->action_data);
|
|
|
|
|
|
tracing: Add a check_val() check before updating cond_snapshot() track_val
Without this check a snapshot is taken whenever a bucket's max is hit,
rather than only when the global max is hit, as it should be.
Before:
In this example, we do a first run of the workload (cyclictest),
examine the output, note the max ('triggering value') (347), then do
a second run and note the max again.
In this case, the max in the second run (39) is below the max in the
first run, but since we haven't cleared the histogram, the first max
is still in the histogram and is higher than any other max, so it
should still be the max for the snapshot. It isn't however - the
value should still be 347 after the second run.
# echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="cyclictest"' >> /sys/kernel/debug/tracing/events/sched/sched_waking/trigger
# echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:onmax($wakeup_lat).save(next_prio,next_comm,prev_pid,prev_prio,prev_comm):onmax($wakeup_lat).snapshot() if next_comm=="cyclictest"' >> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
# cyclictest -p 80 -n -s -t 2 -D 2
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 2143 } hitcount: 199
max: 44 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/4
{ next_pid: 2145 } hitcount: 1325
max: 38 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/2
{ next_pid: 2144 } hitcount: 1982
max: 347 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
Snapshot taken (see tracing/snapshot). Details:
triggering value { onmax($wakeup_lat) }: 347
triggered by event with key: { next_pid: 2144 }
# cyclictest -p 80 -n -s -t 2 -D 2
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 2143 } hitcount: 199
max: 44 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/4
{ next_pid: 2148 } hitcount: 199
max: 16 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/1
{ next_pid: 2145 } hitcount: 1325
max: 38 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/2
{ next_pid: 2150 } hitcount: 1326
max: 39 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/4
{ next_pid: 2144 } hitcount: 1982
max: 347 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
{ next_pid: 2149 } hitcount: 1983
max: 130 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/0
Snapshot taken (see tracing/snapshot). Details:
triggering value { onmax($wakeup_lat) }: 39
triggered by event with key: { next_pid: 2150 }
After:
In this example, we do a first run of the workload (cyclictest),
examine the output, note the max ('triggering value') (375), then do
a second run and note the max again.
In this case, the max in the second run is still 375, the highest in
any bucket, as it should be.
# cyclictest -p 80 -n -s -t 2 -D 2
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 2072 } hitcount: 200
max: 28 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/5
{ next_pid: 2074 } hitcount: 1323
max: 375 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/2
{ next_pid: 2073 } hitcount: 1980
max: 153 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
Snapshot taken (see tracing/snapshot). Details:
triggering value { onmax($wakeup_lat) }: 375
triggered by event with key: { next_pid: 2074 }
# cyclictest -p 80 -n -s -t 2 -D 2
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 2101 } hitcount: 199
max: 49 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
{ next_pid: 2072 } hitcount: 200
max: 28 next_prio: 120 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/5
{ next_pid: 2074 } hitcount: 1323
max: 375 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/2
{ next_pid: 2103 } hitcount: 1325
max: 74 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/4
{ next_pid: 2073 } hitcount: 1980
max: 153 next_prio: 19 next_comm: cyclictest
prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
{ next_pid: 2102 } hitcount: 1981
max: 84 next_prio: 19 next_comm: cyclictest
prev_pid: 12 prev_prio: 120 prev_comm: kworker/0:1
Snapshot taken (see tracing/snapshot). Details:
triggering value { onmax($wakeup_lat) }: 375
triggered by event with key: { next_pid: 2074 }
Link: http://lkml.kernel.org/r/95958351329f129c07504b4d1769c47a97b70d65.1555597045.git.tom.zanussi@linux.intel.com
Cc: stable@vger.kernel.org
Fixes: a3785b7eca8fd ("tracing: Add hist trigger snapshot() action")
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-04-19 00:18:52 +09:00
|
|
|
if (!action->track_data.check_val(track_data->track_val, track_val))
|
|
|
|
|
return false;
|
|
|
|
|
|
2019-02-14 08:42:46 +09:00
|
|
|
track_data->track_val = track_val;
|
|
|
|
|
memcpy(track_data->key, context->key, track_data->key_len);
|
|
|
|
|
|
|
|
|
|
elt_data = context->elt->private_data;
|
|
|
|
|
track_elt_data = track_data->elt.private_data;
|
|
|
|
|
if (elt_data->comm)
|
2019-03-06 01:11:59 +09:00
|
|
|
strncpy(track_elt_data->comm, elt_data->comm, TASK_COMM_LEN);
|
2019-02-14 08:42:46 +09:00
|
|
|
|
|
|
|
|
track_data->updated = true;
|
|
|
|
|
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void save_track_data_snapshot(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt, void *rec,
|
|
|
|
|
struct ring_buffer_event *rbe, void *key,
|
|
|
|
|
struct action_data *data,
|
|
|
|
|
u64 *var_ref_vals)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_file *file = hist_data->event_file;
|
|
|
|
|
struct snapshot_context context;
|
|
|
|
|
|
|
|
|
|
context.elt = elt;
|
|
|
|
|
context.key = key;
|
|
|
|
|
|
|
|
|
|
tracing_snapshot_cond(file->tr, &context);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void hist_trigger_print_key(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data,
|
|
|
|
|
void *key,
|
|
|
|
|
struct tracing_map_elt *elt);
|
|
|
|
|
|
|
|
|
|
static struct action_data *snapshot_action(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
if (!hist_data->n_actions)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_actions; i++) {
|
|
|
|
|
struct action_data *data = hist_data->actions[i];
|
|
|
|
|
|
|
|
|
|
if (data->action == ACTION_SNAPSHOT)
|
|
|
|
|
return data;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void track_data_snapshot_print(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_file *file = hist_data->event_file;
|
|
|
|
|
struct track_data *track_data;
|
|
|
|
|
struct action_data *action;
|
|
|
|
|
|
|
|
|
|
track_data = tracing_cond_snapshot_data(file->tr);
|
|
|
|
|
if (!track_data)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
if (!track_data->updated)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
action = snapshot_action(hist_data);
|
|
|
|
|
if (!action)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
seq_puts(m, "\nSnapshot taken (see tracing/snapshot). Details:\n");
|
|
|
|
|
seq_printf(m, "\ttriggering value { %s(%s) }: %10llu",
|
|
|
|
|
action->handler == HANDLER_ONMAX ? "onmax" : "onchange",
|
|
|
|
|
action->track_data.var_str, track_data->track_val);
|
|
|
|
|
|
|
|
|
|
seq_puts(m, "\ttriggered by event with key: ");
|
|
|
|
|
hist_trigger_print_key(m, hist_data, track_data->key, &track_data->elt);
|
|
|
|
|
seq_putc(m, '\n');
|
|
|
|
|
}
|
|
|
|
|
#else
|
|
|
|
|
static bool cond_snapshot_update(struct trace_array *tr, void *cond_data)
|
|
|
|
|
{
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
static void save_track_data_snapshot(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt, void *rec,
|
|
|
|
|
struct ring_buffer_event *rbe, void *key,
|
|
|
|
|
struct action_data *data,
|
|
|
|
|
u64 *var_ref_vals) {}
|
|
|
|
|
static void track_data_snapshot_print(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data) {}
|
|
|
|
|
#endif /* CONFIG_TRACER_SNAPSHOT */
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
static void track_data_print(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct action_data *data)
|
|
|
|
|
{
|
|
|
|
|
u64 track_val = get_track_val(hist_data, elt, data);
|
|
|
|
|
unsigned int i, save_var_idx;
|
|
|
|
|
|
|
|
|
|
if (data->handler == HANDLER_ONMAX)
|
|
|
|
|
seq_printf(m, "\n\tmax: %10llu", track_val);
|
2019-02-14 08:42:48 +09:00
|
|
|
else if (data->handler == HANDLER_ONCHANGE)
|
|
|
|
|
seq_printf(m, "\n\tchanged: %10llu", track_val);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
|
2019-02-14 08:42:46 +09:00
|
|
|
if (data->action == ACTION_SNAPSHOT)
|
|
|
|
|
return;
|
|
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
for (i = 0; i < hist_data->n_save_vars; i++) {
|
|
|
|
|
struct hist_field *save_val = hist_data->save_vars[i]->val;
|
|
|
|
|
struct hist_field *save_var = hist_data->save_vars[i]->var;
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
u64 val;
|
|
|
|
|
|
|
|
|
|
save_var_idx = save_var->var.idx;
|
|
|
|
|
|
|
|
|
|
val = tracing_map_read_var(elt, save_var_idx);
|
|
|
|
|
|
|
|
|
|
if (save_val->flags & HIST_FIELD_FL_STRING) {
|
|
|
|
|
seq_printf(m, " %s: %-32s", save_var->var.name,
|
|
|
|
|
(char *)(uintptr_t)(val));
|
|
|
|
|
} else
|
|
|
|
|
seq_printf(m, " %s: %10llu", save_var->var.name, val);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
static void ontrack_action(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt, void *rec,
|
|
|
|
|
struct ring_buffer_event *rbe, void *key,
|
|
|
|
|
struct action_data *data, u64 *var_ref_vals)
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
{
|
2019-02-14 08:42:44 +09:00
|
|
|
u64 var_val = var_ref_vals[data->track_data.var_ref->var_ref_idx];
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
if (check_track_val(elt, data, var_val)) {
|
|
|
|
|
save_track_val(hist_data, elt, data, var_val);
|
|
|
|
|
save_track_data(hist_data, elt, rec, rbe, key, data, var_ref_vals);
|
|
|
|
|
}
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:43 +09:00
|
|
|
static void action_data_destroy(struct action_data *data)
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
2019-02-14 08:42:43 +09:00
|
|
|
lockdep_assert_held(&event_mutex);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
kfree(data->action_name);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
|
|
|
|
|
for (i = 0; i < data->n_params; i++)
|
|
|
|
|
kfree(data->params[i]);
|
|
|
|
|
|
2019-02-14 08:42:43 +09:00
|
|
|
if (data->synth_event)
|
|
|
|
|
data->synth_event->ref--;
|
|
|
|
|
|
2019-02-14 08:42:50 +09:00
|
|
|
kfree(data->synth_event_name);
|
|
|
|
|
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
kfree(data);
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
static void track_data_destroy(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct action_data *data)
|
2019-02-14 08:42:43 +09:00
|
|
|
{
|
2019-02-14 08:42:46 +09:00
|
|
|
struct trace_event_file *file = hist_data->event_file;
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
destroy_hist_field(data->track_data.track_var, 0);
|
2019-02-14 08:42:43 +09:00
|
|
|
|
2019-02-14 08:42:46 +09:00
|
|
|
if (data->action == ACTION_SNAPSHOT) {
|
|
|
|
|
struct track_data *track_data;
|
|
|
|
|
|
|
|
|
|
track_data = tracing_cond_snapshot_data(file->tr);
|
|
|
|
|
if (track_data && track_data->hist_data == hist_data) {
|
|
|
|
|
tracing_snapshot_cond_disable(file->tr);
|
|
|
|
|
track_data_free(track_data);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
kfree(data->track_data.var_str);
|
2019-02-14 08:42:43 +09:00
|
|
|
|
|
|
|
|
action_data_destroy(data);
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
static int action_create(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct action_data *data);
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
static int track_data_create(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct action_data *data)
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
{
|
2019-02-14 08:42:44 +09:00
|
|
|
struct hist_field *var_field, *ref_field, *track_var = NULL;
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
struct trace_event_file *file = hist_data->event_file;
|
2019-04-02 11:30:22 +09:00
|
|
|
struct trace_array *tr = file->tr;
|
2019-02-14 08:42:44 +09:00
|
|
|
char *track_data_var_str;
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
int ret = 0;
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
track_data_var_str = data->track_data.var_str;
|
|
|
|
|
if (track_data_var_str[0] != '$') {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_ONX_NOT_VAR, errpos(track_data_var_str));
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
return -EINVAL;
|
2018-01-16 11:52:05 +09:00
|
|
|
}
|
2019-02-14 08:42:44 +09:00
|
|
|
track_data_var_str++;
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
var_field = find_target_event_var(hist_data, NULL, NULL, track_data_var_str);
|
2018-01-16 11:52:05 +09:00
|
|
|
if (!var_field) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_ONX_VAR_NOT_FOUND, errpos(track_data_var_str));
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
return -EINVAL;
|
2018-01-16 11:52:05 +09:00
|
|
|
}
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
|
2018-12-19 05:33:23 +09:00
|
|
|
ref_field = create_var_ref(hist_data, var_field, NULL, NULL);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
if (!ref_field)
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
data->track_data.var_ref = ref_field;
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
if (data->handler == HANDLER_ONMAX)
|
|
|
|
|
track_var = create_var(hist_data, file, "__max", sizeof(u64), "u64");
|
|
|
|
|
if (IS_ERR(track_var)) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_ONX_VAR_CREATE_FAIL, 0);
|
2019-02-14 08:42:44 +09:00
|
|
|
ret = PTR_ERR(track_var);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
goto out;
|
|
|
|
|
}
|
2019-02-14 08:42:48 +09:00
|
|
|
|
|
|
|
|
if (data->handler == HANDLER_ONCHANGE)
|
|
|
|
|
track_var = create_var(hist_data, file, "__change", sizeof(u64), "u64");
|
|
|
|
|
if (IS_ERR(track_var)) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_ONX_VAR_CREATE_FAIL, 0);
|
2019-02-14 08:42:48 +09:00
|
|
|
ret = PTR_ERR(track_var);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
2019-02-14 08:42:44 +09:00
|
|
|
data->track_data.track_var = track_var;
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
ret = action_create(hist_data, data);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2019-04-02 11:30:22 +09:00
|
|
|
static int parse_action_params(struct trace_array *tr, char *params,
|
|
|
|
|
struct action_data *data)
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
{
|
|
|
|
|
char *param, *saved_param;
|
2019-02-14 08:42:50 +09:00
|
|
|
bool first_param = true;
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
while (params) {
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
if (data->n_params >= SYNTH_FIELDS_MAX) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_TOO_MANY_PARAMS, 0);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
goto out;
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
}
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
|
|
|
|
|
param = strsep(¶ms, ",");
|
|
|
|
|
if (!param) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_PARAM_NOT_FOUND, 0);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
param = strstrip(param);
|
|
|
|
|
if (strlen(param) < 2) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_INVALID_PARAM, errpos(param));
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
saved_param = kstrdup(param, GFP_KERNEL);
|
|
|
|
|
if (!saved_param) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:50 +09:00
|
|
|
if (first_param && data->use_trace_keyword) {
|
|
|
|
|
data->synth_event_name = saved_param;
|
|
|
|
|
first_param = false;
|
|
|
|
|
continue;
|
|
|
|
|
}
|
|
|
|
|
first_param = false;
|
|
|
|
|
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
data->params[data->n_params++] = saved_param;
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2019-04-02 11:30:22 +09:00
|
|
|
static int action_parse(struct trace_array *tr, char *str, struct action_data *data,
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
enum handler_id handler)
|
|
|
|
|
{
|
|
|
|
|
char *action_name;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
strsep(&str, ".");
|
|
|
|
|
if (!str) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_ACTION_NOT_FOUND, 0);
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
action_name = strsep(&str, "(");
|
|
|
|
|
if (!action_name || !str) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_ACTION_NOT_FOUND, 0);
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (str_has_prefix(action_name, "save")) {
|
|
|
|
|
char *params = strsep(&str, ")");
|
|
|
|
|
|
|
|
|
|
if (!params) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_NO_SAVE_PARAMS, 0);
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2019-04-02 11:30:22 +09:00
|
|
|
ret = parse_action_params(tr, params, data);
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
|
|
if (handler == HANDLER_ONMAX)
|
2019-02-14 08:42:44 +09:00
|
|
|
data->track_data.check_val = check_track_val_max;
|
2019-02-14 08:42:48 +09:00
|
|
|
else if (handler == HANDLER_ONCHANGE)
|
|
|
|
|
data->track_data.check_val = check_track_val_changed;
|
2019-02-14 08:42:44 +09:00
|
|
|
else {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_ACTION_MISMATCH, errpos(action_name));
|
2019-02-14 08:42:44 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
data->track_data.save_data = save_track_data_vars;
|
|
|
|
|
data->fn = ontrack_action;
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
data->action = ACTION_SAVE;
|
2019-02-14 08:42:46 +09:00
|
|
|
} else if (str_has_prefix(action_name, "snapshot")) {
|
|
|
|
|
char *params = strsep(&str, ")");
|
|
|
|
|
|
|
|
|
|
if (!str) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_NO_CLOSING_PAREN, errpos(params));
|
2019-02-14 08:42:46 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (handler == HANDLER_ONMAX)
|
|
|
|
|
data->track_data.check_val = check_track_val_max;
|
2019-02-14 08:42:48 +09:00
|
|
|
else if (handler == HANDLER_ONCHANGE)
|
|
|
|
|
data->track_data.check_val = check_track_val_changed;
|
2019-02-14 08:42:46 +09:00
|
|
|
else {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_ACTION_MISMATCH, errpos(action_name));
|
2019-02-14 08:42:46 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
data->track_data.save_data = save_track_data_snapshot;
|
|
|
|
|
data->fn = ontrack_action;
|
|
|
|
|
data->action = ACTION_SNAPSHOT;
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
} else {
|
|
|
|
|
char *params = strsep(&str, ")");
|
|
|
|
|
|
2019-02-14 08:42:50 +09:00
|
|
|
if (str_has_prefix(action_name, "trace"))
|
|
|
|
|
data->use_trace_keyword = true;
|
|
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
if (params) {
|
2019-04-02 11:30:22 +09:00
|
|
|
ret = parse_action_params(tr, params, data);
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
if (handler == HANDLER_ONMAX)
|
|
|
|
|
data->track_data.check_val = check_track_val_max;
|
2019-02-14 08:42:48 +09:00
|
|
|
else if (handler == HANDLER_ONCHANGE)
|
|
|
|
|
data->track_data.check_val = check_track_val_changed;
|
2019-02-14 08:42:44 +09:00
|
|
|
|
|
|
|
|
if (handler != HANDLER_ONMATCH) {
|
|
|
|
|
data->track_data.save_data = action_trace;
|
|
|
|
|
data->fn = ontrack_action;
|
|
|
|
|
} else
|
|
|
|
|
data->fn = action_trace;
|
|
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
data->action = ACTION_TRACE;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
data->action_name = kstrdup(action_name, GFP_KERNEL);
|
|
|
|
|
if (!data->action_name) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
data->handler = handler;
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
static struct action_data *track_data_parse(struct hist_trigger_data *hist_data,
|
|
|
|
|
char *str, enum handler_id handler)
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
{
|
|
|
|
|
struct action_data *data;
|
|
|
|
|
int ret = -EINVAL;
|
2019-02-14 08:42:44 +09:00
|
|
|
char *var_str;
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
|
|
|
|
|
data = kzalloc(sizeof(*data), GFP_KERNEL);
|
|
|
|
|
if (!data)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
var_str = strsep(&str, ")");
|
|
|
|
|
if (!var_str || !str) {
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
data->track_data.var_str = kstrdup(var_str, GFP_KERNEL);
|
|
|
|
|
if (!data->track_data.var_str) {
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
2019-04-02 11:30:22 +09:00
|
|
|
ret = action_parse(hist_data->event_file->tr, str, data, handler);
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
if (ret)
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
goto free;
|
|
|
|
|
out:
|
|
|
|
|
return data;
|
|
|
|
|
free:
|
2019-02-14 08:42:44 +09:00
|
|
|
track_data_destroy(hist_data, data);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
data = ERR_PTR(ret);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:52:00 +09:00
|
|
|
static void onmatch_destroy(struct action_data *data)
|
|
|
|
|
{
|
2019-02-14 08:42:43 +09:00
|
|
|
kfree(data->match_data.event);
|
|
|
|
|
kfree(data->match_data.event_system);
|
2018-01-16 11:52:00 +09:00
|
|
|
|
2019-02-14 08:42:43 +09:00
|
|
|
action_data_destroy(data);
|
2018-01-16 11:52:00 +09:00
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
static void destroy_field_var(struct field_var *field_var)
|
|
|
|
|
{
|
|
|
|
|
if (!field_var)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
destroy_hist_field(field_var->var, 0);
|
|
|
|
|
destroy_hist_field(field_var->val, 0);
|
|
|
|
|
|
|
|
|
|
kfree(field_var);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void destroy_field_vars(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_field_vars; i++)
|
|
|
|
|
destroy_field_var(hist_data->field_vars[i]);
|
2020-04-22 15:15:06 +09:00
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_save_vars; i++)
|
|
|
|
|
destroy_field_var(hist_data->save_vars[i]);
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:52:00 +09:00
|
|
|
static void save_field_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct field_var *field_var)
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
{
|
|
|
|
|
hist_data->field_vars[hist_data->n_field_vars++] = field_var;
|
|
|
|
|
|
|
|
|
|
if (field_var->val->flags & HIST_FIELD_FL_STRING)
|
|
|
|
|
hist_data->n_field_var_str++;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:52:00 +09:00
|
|
|
|
|
|
|
|
static int check_synth_field(struct synth_event *event,
|
|
|
|
|
struct hist_field *hist_field,
|
|
|
|
|
unsigned int field_pos)
|
|
|
|
|
{
|
|
|
|
|
struct synth_field *field;
|
|
|
|
|
|
|
|
|
|
if (field_pos >= event->n_fields)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
field = event->fields[field_pos];
|
|
|
|
|
|
|
|
|
|
if (strcmp(field->type, hist_field->type) != 0)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
trace_action_find_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct action_data *data,
|
|
|
|
|
char *system, char *event, char *var)
|
2018-01-16 11:52:00 +09:00
|
|
|
{
|
2019-04-02 11:30:22 +09:00
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
2018-01-16 11:52:00 +09:00
|
|
|
struct hist_field *hist_field;
|
|
|
|
|
|
|
|
|
|
var++; /* skip '$' */
|
|
|
|
|
|
|
|
|
|
hist_field = find_target_event_var(hist_data, system, event, var);
|
|
|
|
|
if (!hist_field) {
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
if (!system && data->handler == HANDLER_ONMATCH) {
|
2019-02-14 08:42:43 +09:00
|
|
|
system = data->match_data.event_system;
|
|
|
|
|
event = data->match_data.event;
|
2018-01-16 11:52:00 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
hist_field = find_event_var(hist_data, system, event, var);
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:52:05 +09:00
|
|
|
if (!hist_field)
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_PARAM_NOT_FOUND, errpos(var));
|
2018-01-16 11:52:05 +09:00
|
|
|
|
2018-01-16 11:52:00 +09:00
|
|
|
return hist_field;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
trace_action_create_field_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct action_data *data, char *system,
|
|
|
|
|
char *event, char *var)
|
2018-01-16 11:52:00 +09:00
|
|
|
{
|
|
|
|
|
struct hist_field *hist_field = NULL;
|
|
|
|
|
struct field_var *field_var;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* First try to create a field var on the target event (the
|
|
|
|
|
* currently being defined). This will create a variable for
|
|
|
|
|
* unqualified fields on the target event, or if qualified,
|
|
|
|
|
* target fields that have qualified names matching the target.
|
|
|
|
|
*/
|
|
|
|
|
field_var = create_target_field_var(hist_data, system, event, var);
|
|
|
|
|
|
|
|
|
|
if (field_var && !IS_ERR(field_var)) {
|
|
|
|
|
save_field_var(hist_data, field_var);
|
|
|
|
|
hist_field = field_var->var;
|
|
|
|
|
} else {
|
|
|
|
|
field_var = NULL;
|
|
|
|
|
/*
|
|
|
|
|
* If no explicit system.event is specfied, default to
|
|
|
|
|
* looking for fields on the onmatch(system.event.xxx)
|
|
|
|
|
* event.
|
|
|
|
|
*/
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
if (!system && data->handler == HANDLER_ONMATCH) {
|
2019-02-14 08:42:43 +09:00
|
|
|
system = data->match_data.event_system;
|
|
|
|
|
event = data->match_data.event;
|
2018-01-16 11:52:00 +09:00
|
|
|
}
|
|
|
|
|
|
2021-08-08 13:30:11 +09:00
|
|
|
if (!event)
|
|
|
|
|
goto free;
|
2018-01-16 11:52:00 +09:00
|
|
|
/*
|
|
|
|
|
* At this point, we're looking at a field on another
|
|
|
|
|
* event. Because we can't modify a hist trigger on
|
|
|
|
|
* another event to add a variable for a field, we need
|
|
|
|
|
* to create a new trigger on that event and create the
|
|
|
|
|
* variable at the same time.
|
|
|
|
|
*/
|
|
|
|
|
hist_field = create_field_var_hist(hist_data, system, event, var);
|
|
|
|
|
if (IS_ERR(hist_field))
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
return hist_field;
|
|
|
|
|
free:
|
|
|
|
|
destroy_field_var(field_var);
|
|
|
|
|
hist_field = NULL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
static int trace_action_create(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct action_data *data)
|
2018-01-16 11:52:00 +09:00
|
|
|
{
|
2019-04-02 11:30:22 +09:00
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
2018-01-16 11:52:00 +09:00
|
|
|
char *event_name, *param, *system = NULL;
|
|
|
|
|
struct hist_field *hist_field, *var_ref;
|
2020-01-30 11:18:18 +09:00
|
|
|
unsigned int i;
|
2018-01-16 11:52:00 +09:00
|
|
|
unsigned int field_pos = 0;
|
|
|
|
|
struct synth_event *event;
|
2019-02-14 08:42:50 +09:00
|
|
|
char *synth_event_name;
|
2020-01-30 11:18:18 +09:00
|
|
|
int var_ref_idx, ret = 0;
|
2018-01-16 11:52:00 +09:00
|
|
|
|
2018-11-05 18:04:01 +09:00
|
|
|
lockdep_assert_held(&event_mutex);
|
|
|
|
|
|
2019-02-14 08:42:50 +09:00
|
|
|
if (data->use_trace_keyword)
|
|
|
|
|
synth_event_name = data->synth_event_name;
|
|
|
|
|
else
|
|
|
|
|
synth_event_name = data->action_name;
|
|
|
|
|
|
|
|
|
|
event = find_synth_event(synth_event_name);
|
2018-01-16 11:52:00 +09:00
|
|
|
if (!event) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_SYNTH_EVENT_NOT_FOUND, errpos(synth_event_name));
|
2018-01-16 11:52:00 +09:00
|
|
|
return -EINVAL;
|
|
|
|
|
}
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
|
2018-01-16 11:52:00 +09:00
|
|
|
event->ref++;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < data->n_params; i++) {
|
|
|
|
|
char *p;
|
|
|
|
|
|
|
|
|
|
p = param = kstrdup(data->params[i], GFP_KERNEL);
|
|
|
|
|
if (!param) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
system = strsep(¶m, ".");
|
|
|
|
|
if (!param) {
|
|
|
|
|
param = (char *)system;
|
|
|
|
|
system = event_name = NULL;
|
|
|
|
|
} else {
|
|
|
|
|
event_name = strsep(¶m, ".");
|
|
|
|
|
if (!param) {
|
|
|
|
|
kfree(p);
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (param[0] == '$')
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
hist_field = trace_action_find_var(hist_data, data,
|
|
|
|
|
system, event_name,
|
|
|
|
|
param);
|
2018-01-16 11:52:00 +09:00
|
|
|
else
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
hist_field = trace_action_create_field_var(hist_data,
|
|
|
|
|
data,
|
|
|
|
|
system,
|
|
|
|
|
event_name,
|
|
|
|
|
param);
|
2018-01-16 11:52:00 +09:00
|
|
|
|
|
|
|
|
if (!hist_field) {
|
|
|
|
|
kfree(p);
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (check_synth_field(event, hist_field, field_pos) == 0) {
|
2018-12-19 05:33:23 +09:00
|
|
|
var_ref = create_var_ref(hist_data, hist_field,
|
|
|
|
|
system, event_name);
|
2018-01-16 11:52:00 +09:00
|
|
|
if (!var_ref) {
|
|
|
|
|
kfree(p);
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
2020-01-30 11:18:18 +09:00
|
|
|
var_ref_idx = find_var_ref_idx(hist_data, var_ref);
|
|
|
|
|
if (WARN_ON(var_ref_idx < 0)) {
|
|
|
|
|
ret = var_ref_idx;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
data->var_ref_idx[i] = var_ref_idx;
|
|
|
|
|
|
2018-01-16 11:52:00 +09:00
|
|
|
field_pos++;
|
|
|
|
|
kfree(p);
|
|
|
|
|
continue;
|
|
|
|
|
}
|
|
|
|
|
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_SYNTH_TYPE_MISMATCH, errpos(param));
|
2018-01-16 11:52:00 +09:00
|
|
|
kfree(p);
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (field_pos != event->n_fields) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_SYNTH_COUNT_MISMATCH, errpos(event->name));
|
2018-01-16 11:52:00 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:43 +09:00
|
|
|
data->synth_event = event;
|
2018-01-16 11:52:00 +09:00
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
err:
|
|
|
|
|
event->ref--;
|
|
|
|
|
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
static int action_create(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct action_data *data)
|
|
|
|
|
{
|
2019-02-14 08:42:46 +09:00
|
|
|
struct trace_event_file *file = hist_data->event_file;
|
2019-04-02 11:30:22 +09:00
|
|
|
struct trace_array *tr = file->tr;
|
2019-02-14 08:42:46 +09:00
|
|
|
struct track_data *track_data;
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
struct field_var *field_var;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
char *param;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
if (data->action == ACTION_TRACE)
|
|
|
|
|
return trace_action_create(hist_data, data);
|
|
|
|
|
|
2019-02-14 08:42:46 +09:00
|
|
|
if (data->action == ACTION_SNAPSHOT) {
|
|
|
|
|
track_data = track_data_alloc(hist_data->key_size, data, hist_data);
|
|
|
|
|
if (IS_ERR(track_data)) {
|
|
|
|
|
ret = PTR_ERR(track_data);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
ret = tracing_snapshot_cond_enable(file->tr, track_data,
|
|
|
|
|
cond_snapshot_update);
|
|
|
|
|
if (ret)
|
|
|
|
|
track_data_free(track_data);
|
|
|
|
|
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
if (data->action == ACTION_SAVE) {
|
|
|
|
|
if (hist_data->n_save_vars) {
|
|
|
|
|
ret = -EEXIST;
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_TOO_MANY_SAVE_ACTIONS, 0);
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < data->n_params; i++) {
|
|
|
|
|
param = kstrdup(data->params[i], GFP_KERNEL);
|
|
|
|
|
if (!param) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
field_var = create_target_field_var(hist_data, NULL, NULL, param);
|
|
|
|
|
if (IS_ERR(field_var)) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_FIELD_VAR_CREATE_FAIL,
|
|
|
|
|
errpos(param));
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
ret = PTR_ERR(field_var);
|
|
|
|
|
kfree(param);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
hist_data->save_vars[hist_data->n_save_vars++] = field_var;
|
|
|
|
|
if (field_var->val->flags & HIST_FIELD_FL_STRING)
|
|
|
|
|
hist_data->n_save_var_str++;
|
|
|
|
|
kfree(param);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int onmatch_create(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct action_data *data)
|
|
|
|
|
{
|
|
|
|
|
return action_create(hist_data, data);
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:52:00 +09:00
|
|
|
static struct action_data *onmatch_parse(struct trace_array *tr, char *str)
|
|
|
|
|
{
|
|
|
|
|
char *match_event, *match_event_system;
|
|
|
|
|
struct action_data *data;
|
|
|
|
|
int ret = -EINVAL;
|
|
|
|
|
|
|
|
|
|
data = kzalloc(sizeof(*data), GFP_KERNEL);
|
|
|
|
|
if (!data)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
match_event = strsep(&str, ")");
|
2018-01-16 11:52:05 +09:00
|
|
|
if (!match_event || !str) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_NO_CLOSING_PAREN, errpos(match_event));
|
2018-01-16 11:52:00 +09:00
|
|
|
goto free;
|
2018-01-16 11:52:05 +09:00
|
|
|
}
|
2018-01-16 11:52:00 +09:00
|
|
|
|
|
|
|
|
match_event_system = strsep(&match_event, ".");
|
2018-01-16 11:52:05 +09:00
|
|
|
if (!match_event) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_SUBSYS_NOT_FOUND, errpos(match_event_system));
|
2018-01-16 11:52:00 +09:00
|
|
|
goto free;
|
2018-01-16 11:52:05 +09:00
|
|
|
}
|
2018-01-16 11:52:00 +09:00
|
|
|
|
2018-01-16 11:52:05 +09:00
|
|
|
if (IS_ERR(event_file(tr, match_event_system, match_event))) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_INVALID_SUBSYS_EVENT, errpos(match_event));
|
2018-01-16 11:52:00 +09:00
|
|
|
goto free;
|
2018-01-16 11:52:05 +09:00
|
|
|
}
|
2018-01-16 11:52:00 +09:00
|
|
|
|
2019-02-14 08:42:43 +09:00
|
|
|
data->match_data.event = kstrdup(match_event, GFP_KERNEL);
|
|
|
|
|
if (!data->match_data.event) {
|
2018-01-16 11:52:00 +09:00
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:43 +09:00
|
|
|
data->match_data.event_system = kstrdup(match_event_system, GFP_KERNEL);
|
|
|
|
|
if (!data->match_data.event_system) {
|
2018-01-16 11:52:00 +09:00
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
2019-04-02 11:30:22 +09:00
|
|
|
ret = action_parse(tr, str, data, HANDLER_ONMATCH);
|
2018-01-16 11:52:00 +09:00
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
|
|
|
|
out:
|
|
|
|
|
return data;
|
|
|
|
|
free:
|
|
|
|
|
onmatch_destroy(data);
|
|
|
|
|
data = ERR_PTR(ret);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
static int create_hitcount_val(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
hist_data->fields[HITCOUNT_IDX] =
|
2018-01-16 11:51:49 +09:00
|
|
|
create_hist_field(hist_data, NULL, HIST_FIELD_FL_HITCOUNT, NULL);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
if (!hist_data->fields[HITCOUNT_IDX])
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
|
|
hist_data->n_vals++;
|
2018-01-16 11:51:49 +09:00
|
|
|
hist_data->n_fields++;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
|
|
|
|
if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
static int __create_val_field(struct hist_trigger_data *hist_data,
|
|
|
|
|
unsigned int val_idx,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *var_name, char *field_str,
|
|
|
|
|
unsigned long flags)
|
2016-03-04 03:54:43 +09:00
|
|
|
{
|
2018-01-16 11:51:52 +09:00
|
|
|
struct hist_field *hist_field;
|
2016-03-04 03:54:43 +09:00
|
|
|
int ret = 0;
|
|
|
|
|
|
2018-01-16 11:51:52 +09:00
|
|
|
hist_field = parse_expr(hist_data, file, field_str, flags, var_name, 0);
|
|
|
|
|
if (IS_ERR(hist_field)) {
|
|
|
|
|
ret = PTR_ERR(hist_field);
|
2016-03-04 03:54:43 +09:00
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:52 +09:00
|
|
|
hist_data->fields[val_idx] = hist_field;
|
|
|
|
|
|
2016-03-04 03:54:43 +09:00
|
|
|
++hist_data->n_vals;
|
2018-01-16 11:51:49 +09:00
|
|
|
++hist_data->n_fields;
|
2016-03-04 03:54:43 +09:00
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX))
|
2016-03-04 03:54:43 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
static int create_val_field(struct hist_trigger_data *hist_data,
|
|
|
|
|
unsigned int val_idx,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *field_str)
|
|
|
|
|
{
|
|
|
|
|
if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX))
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
return __create_val_field(hist_data, val_idx, file, NULL, field_str, 0);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int create_var_field(struct hist_trigger_data *hist_data,
|
|
|
|
|
unsigned int val_idx,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *var_name, char *expr_str)
|
|
|
|
|
{
|
2019-04-02 11:30:22 +09:00
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
2018-01-16 11:51:49 +09:00
|
|
|
unsigned long flags = 0;
|
|
|
|
|
|
|
|
|
|
if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX))
|
|
|
|
|
return -EINVAL;
|
2018-01-16 11:52:05 +09:00
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
if (find_var(hist_data, file, var_name) && !hist_data->remove) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_DUPLICATE_VAR, errpos(var_name));
|
2018-01-16 11:51:49 +09:00
|
|
|
return -EINVAL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
flags |= HIST_FIELD_FL_VAR;
|
|
|
|
|
hist_data->n_vars++;
|
|
|
|
|
if (WARN_ON(hist_data->n_vars > TRACING_MAP_VARS_MAX))
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
return __create_val_field(hist_data, val_idx, file, var_name, expr_str, flags);
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
static int create_val_fields(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
2016-03-04 03:54:43 +09:00
|
|
|
char *fields_str, *field_str;
|
2018-01-16 11:51:49 +09:00
|
|
|
unsigned int i, j = 1;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
ret = create_hitcount_val(hist_data);
|
2016-03-04 03:54:43 +09:00
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
2016-03-04 03:54:43 +09:00
|
|
|
fields_str = hist_data->attrs->vals_str;
|
|
|
|
|
if (!fields_str)
|
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
|
|
for (i = 0, j = 1; i < TRACING_MAP_VALS_MAX &&
|
|
|
|
|
j < TRACING_MAP_VALS_MAX; i++) {
|
|
|
|
|
field_str = strsep(&fields_str, ",");
|
|
|
|
|
if (!field_str)
|
|
|
|
|
break;
|
2018-01-16 11:51:49 +09:00
|
|
|
|
2016-03-04 03:54:43 +09:00
|
|
|
if (strcmp(field_str, "hitcount") == 0)
|
|
|
|
|
continue;
|
2018-01-16 11:51:49 +09:00
|
|
|
|
2016-03-04 03:54:43 +09:00
|
|
|
ret = create_val_field(hist_data, j++, file, field_str);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
2018-01-16 11:51:49 +09:00
|
|
|
|
2016-03-04 03:54:43 +09:00
|
|
|
if (fields_str && (strcmp(fields_str, "hitcount") != 0))
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
out:
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int create_key_field(struct hist_trigger_data *hist_data,
|
|
|
|
|
unsigned int key_idx,
|
2016-03-04 03:54:44 +09:00
|
|
|
unsigned int key_offset,
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *field_str)
|
|
|
|
|
{
|
2019-04-02 11:30:22 +09:00
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
2018-01-16 11:51:49 +09:00
|
|
|
struct hist_field *hist_field = NULL;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
unsigned long flags = 0;
|
|
|
|
|
unsigned int key_size;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
if (WARN_ON(key_idx >= HIST_FIELDS_MAX))
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
flags |= HIST_FIELD_FL_KEY;
|
|
|
|
|
|
2016-03-04 03:54:52 +09:00
|
|
|
if (strcmp(field_str, "stacktrace") == 0) {
|
|
|
|
|
flags |= HIST_FIELD_FL_STACKTRACE;
|
|
|
|
|
key_size = sizeof(unsigned long) * HIST_STACKTRACE_DEPTH;
|
2018-01-16 11:51:49 +09:00
|
|
|
hist_field = create_hist_field(hist_data, NULL, flags, NULL);
|
2016-03-04 03:54:52 +09:00
|
|
|
} else {
|
2018-01-16 11:51:52 +09:00
|
|
|
hist_field = parse_expr(hist_data, file, field_str, flags,
|
|
|
|
|
NULL, 0);
|
|
|
|
|
if (IS_ERR(hist_field)) {
|
|
|
|
|
ret = PTR_ERR(hist_field);
|
|
|
|
|
goto out;
|
2016-03-04 03:54:52 +09:00
|
|
|
}
|
|
|
|
|
|
2019-04-19 00:18:51 +09:00
|
|
|
if (field_has_hist_vars(hist_field, 0)) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_INVALID_REF_KEY, errpos(field_str));
|
2018-01-16 11:51:56 +09:00
|
|
|
destroy_hist_field(hist_field, 0);
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:52 +09:00
|
|
|
key_size = hist_field->size;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:52 +09:00
|
|
|
hist_data->fields[key_idx] = hist_field;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
|
|
|
|
key_size = ALIGN(key_size, sizeof(u64));
|
|
|
|
|
hist_data->fields[key_idx]->size = key_size;
|
2016-03-04 03:54:44 +09:00
|
|
|
hist_data->fields[key_idx]->offset = key_offset;
|
2018-01-16 11:51:52 +09:00
|
|
|
|
2016-03-04 03:54:44 +09:00
|
|
|
hist_data->key_size += key_size;
|
2018-01-16 11:51:52 +09:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
if (hist_data->key_size > HIST_KEY_SIZE_MAX) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
hist_data->n_keys++;
|
2018-01-16 11:51:49 +09:00
|
|
|
hist_data->n_fields++;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
|
|
|
|
if (WARN_ON(hist_data->n_keys > TRACING_MAP_KEYS_MAX))
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
ret = key_size;
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int create_key_fields(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
2016-03-04 03:54:44 +09:00
|
|
|
unsigned int i, key_offset = 0, n_vals = hist_data->n_vals;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
char *fields_str, *field_str;
|
|
|
|
|
int ret = -EINVAL;
|
|
|
|
|
|
|
|
|
|
fields_str = hist_data->attrs->keys_str;
|
|
|
|
|
if (!fields_str)
|
|
|
|
|
goto out;
|
|
|
|
|
|
2016-03-04 03:54:44 +09:00
|
|
|
for (i = n_vals; i < n_vals + TRACING_MAP_KEYS_MAX; i++) {
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
field_str = strsep(&fields_str, ",");
|
|
|
|
|
if (!field_str)
|
|
|
|
|
break;
|
2016-03-04 03:54:44 +09:00
|
|
|
ret = create_key_field(hist_data, i, key_offset,
|
|
|
|
|
file, field_str);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
if (ret < 0)
|
|
|
|
|
goto out;
|
2016-03-04 03:54:44 +09:00
|
|
|
key_offset += ret;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
}
|
|
|
|
|
if (fields_str) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
ret = 0;
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
static int create_var_fields(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i, j = hist_data->n_vals;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
unsigned int n_vars = hist_data->attrs->var_defs.n_vars;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < n_vars; i++) {
|
|
|
|
|
char *var_name = hist_data->attrs->var_defs.name[i];
|
|
|
|
|
char *expr = hist_data->attrs->var_defs.expr[i];
|
|
|
|
|
|
|
|
|
|
ret = create_var_field(hist_data, j++, file, var_name, expr);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void free_var_defs(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) {
|
|
|
|
|
kfree(hist_data->attrs->var_defs.name[i]);
|
|
|
|
|
kfree(hist_data->attrs->var_defs.expr[i]);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
hist_data->attrs->var_defs.n_vars = 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int parse_var_defs(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
2019-04-02 11:30:22 +09:00
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
2018-01-16 11:51:49 +09:00
|
|
|
char *s, *str, *var_name, *field_str;
|
|
|
|
|
unsigned int i, j, n_vars = 0;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->attrs->n_assignments; i++) {
|
|
|
|
|
str = hist_data->attrs->assignment_str[i];
|
|
|
|
|
for (j = 0; j < TRACING_MAP_VARS_MAX; j++) {
|
|
|
|
|
field_str = strsep(&str, ",");
|
|
|
|
|
if (!field_str)
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
|
|
var_name = strsep(&field_str, "=");
|
|
|
|
|
if (!var_name || !field_str) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_MALFORMED_ASSIGNMENT,
|
|
|
|
|
errpos(var_name));
|
2018-01-16 11:51:49 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (n_vars == TRACING_MAP_VARS_MAX) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_TOO_MANY_VARS, errpos(var_name));
|
2018-01-16 11:51:49 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
s = kstrdup(var_name, GFP_KERNEL);
|
|
|
|
|
if (!s) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
hist_data->attrs->var_defs.name[n_vars] = s;
|
|
|
|
|
|
|
|
|
|
s = kstrdup(field_str, GFP_KERNEL);
|
|
|
|
|
if (!s) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
hist_data->attrs->var_defs.expr[n_vars++] = s;
|
|
|
|
|
|
|
|
|
|
hist_data->attrs->var_defs.n_vars = n_vars;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
free:
|
|
|
|
|
free_var_defs(hist_data);
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
static int create_hist_fields(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
int ret;
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
ret = parse_var_defs(hist_data);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
ret = create_val_fields(hist_data, file);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
ret = create_var_fields(hist_data, file);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
ret = create_key_fields(hist_data, file);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
out:
|
2018-01-16 11:51:49 +09:00
|
|
|
free_var_defs(hist_data);
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:45 +09:00
|
|
|
static int is_descending(const char *str)
|
|
|
|
|
{
|
|
|
|
|
if (!str)
|
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
|
|
if (strcmp(str, "descending") == 0)
|
|
|
|
|
return 1;
|
|
|
|
|
|
|
|
|
|
if (strcmp(str, "ascending") == 0)
|
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
static int create_sort_keys(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
2016-03-04 03:54:45 +09:00
|
|
|
char *fields_str = hist_data->attrs->sort_key_str;
|
|
|
|
|
struct tracing_map_sort_key *sort_key;
|
|
|
|
|
int descending, ret = 0;
|
2018-01-16 11:51:49 +09:00
|
|
|
unsigned int i, j, k;
|
2016-03-04 03:54:45 +09:00
|
|
|
|
|
|
|
|
hist_data->n_sort_keys = 1; /* we always have at least one, hitcount */
|
|
|
|
|
|
|
|
|
|
if (!fields_str)
|
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < TRACING_MAP_SORT_KEYS_MAX; i++) {
|
2017-09-23 04:58:22 +09:00
|
|
|
struct hist_field *hist_field;
|
2016-03-04 03:54:45 +09:00
|
|
|
char *field_str, *field_name;
|
2017-09-23 04:58:22 +09:00
|
|
|
const char *test_name;
|
2016-03-04 03:54:45 +09:00
|
|
|
|
|
|
|
|
sort_key = &hist_data->sort_keys[i];
|
|
|
|
|
|
|
|
|
|
field_str = strsep(&fields_str, ",");
|
2019-06-29 02:40:20 +09:00
|
|
|
if (!field_str)
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
|
|
if (!*field_str) {
|
|
|
|
|
ret = -EINVAL;
|
2016-03-04 03:54:45 +09:00
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if ((i == TRACING_MAP_SORT_KEYS_MAX - 1) && fields_str) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
break;
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
2016-03-04 03:54:45 +09:00
|
|
|
field_name = strsep(&field_str, ".");
|
2019-06-29 02:40:20 +09:00
|
|
|
if (!field_name || !*field_name) {
|
2016-03-04 03:54:45 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (strcmp(field_name, "hitcount") == 0) {
|
|
|
|
|
descending = is_descending(field_str);
|
|
|
|
|
if (descending < 0) {
|
|
|
|
|
ret = descending;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
sort_key->descending = descending;
|
|
|
|
|
continue;
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
for (j = 1, k = 1; j < hist_data->n_fields; j++) {
|
|
|
|
|
unsigned int idx;
|
|
|
|
|
|
2017-09-23 04:58:22 +09:00
|
|
|
hist_field = hist_data->fields[j];
|
2018-01-16 11:51:49 +09:00
|
|
|
if (hist_field->flags & HIST_FIELD_FL_VAR)
|
|
|
|
|
continue;
|
|
|
|
|
|
|
|
|
|
idx = k++;
|
|
|
|
|
|
2017-09-23 04:58:22 +09:00
|
|
|
test_name = hist_field_name(hist_field, 0);
|
|
|
|
|
|
|
|
|
|
if (strcmp(field_name, test_name) == 0) {
|
2018-01-16 11:51:49 +09:00
|
|
|
sort_key->field_idx = idx;
|
2016-03-04 03:54:45 +09:00
|
|
|
descending = is_descending(field_str);
|
|
|
|
|
if (descending < 0) {
|
|
|
|
|
ret = descending;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
sort_key->descending = descending;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
if (j == hist_data->n_fields) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
2018-01-16 11:51:49 +09:00
|
|
|
|
2016-03-04 03:54:45 +09:00
|
|
|
hist_data->n_sort_keys = i;
|
|
|
|
|
out:
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:57 +09:00
|
|
|
static void destroy_actions(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_actions; i++) {
|
|
|
|
|
struct action_data *data = hist_data->actions[i];
|
|
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
if (data->handler == HANDLER_ONMATCH)
|
2018-01-16 11:52:00 +09:00
|
|
|
onmatch_destroy(data);
|
2019-02-14 08:42:48 +09:00
|
|
|
else if (data->handler == HANDLER_ONMAX ||
|
|
|
|
|
data->handler == HANDLER_ONCHANGE)
|
2019-02-14 08:42:44 +09:00
|
|
|
track_data_destroy(hist_data, data);
|
2018-01-16 11:52:00 +09:00
|
|
|
else
|
|
|
|
|
kfree(data);
|
2018-01-16 11:51:57 +09:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int parse_actions(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
2018-01-16 11:52:00 +09:00
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
|
|
|
|
struct action_data *data;
|
2018-01-16 11:51:57 +09:00
|
|
|
unsigned int i;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
char *str;
|
2018-12-22 08:40:46 +09:00
|
|
|
int len;
|
2018-01-16 11:51:57 +09:00
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->attrs->n_actions; i++) {
|
|
|
|
|
str = hist_data->attrs->action_str[i];
|
2018-01-16 11:52:00 +09:00
|
|
|
|
2018-12-22 08:40:46 +09:00
|
|
|
if ((len = str_has_prefix(str, "onmatch("))) {
|
|
|
|
|
char *action_str = str + len;
|
2018-01-16 11:52:00 +09:00
|
|
|
|
|
|
|
|
data = onmatch_parse(tr, action_str);
|
|
|
|
|
if (IS_ERR(data)) {
|
|
|
|
|
ret = PTR_ERR(data);
|
|
|
|
|
break;
|
|
|
|
|
}
|
2018-12-22 08:40:46 +09:00
|
|
|
} else if ((len = str_has_prefix(str, "onmax("))) {
|
|
|
|
|
char *action_str = str + len;
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
data = track_data_parse(hist_data, action_str,
|
|
|
|
|
HANDLER_ONMAX);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
if (IS_ERR(data)) {
|
|
|
|
|
ret = PTR_ERR(data);
|
|
|
|
|
break;
|
|
|
|
|
}
|
2019-02-14 08:42:48 +09:00
|
|
|
} else if ((len = str_has_prefix(str, "onchange("))) {
|
|
|
|
|
char *action_str = str + len;
|
|
|
|
|
|
|
|
|
|
data = track_data_parse(hist_data, action_str,
|
|
|
|
|
HANDLER_ONCHANGE);
|
|
|
|
|
if (IS_ERR(data)) {
|
|
|
|
|
ret = PTR_ERR(data);
|
|
|
|
|
break;
|
|
|
|
|
}
|
2018-01-16 11:52:00 +09:00
|
|
|
} else {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
hist_data->actions[hist_data->n_actions++] = data;
|
2018-01-16 11:51:57 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
static int create_actions(struct hist_trigger_data *hist_data)
|
2018-01-16 11:51:57 +09:00
|
|
|
{
|
|
|
|
|
struct action_data *data;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->attrs->n_actions; i++) {
|
|
|
|
|
data = hist_data->actions[i];
|
2018-01-16 11:52:00 +09:00
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
if (data->handler == HANDLER_ONMATCH) {
|
|
|
|
|
ret = onmatch_create(hist_data, data);
|
2018-01-16 11:52:00 +09:00
|
|
|
if (ret)
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
break;
|
2019-02-14 08:42:48 +09:00
|
|
|
} else if (data->handler == HANDLER_ONMAX ||
|
|
|
|
|
data->handler == HANDLER_ONCHANGE) {
|
2019-02-14 08:42:44 +09:00
|
|
|
ret = track_data_create(hist_data, data);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
if (ret)
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
break;
|
|
|
|
|
} else {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
break;
|
2018-01-16 11:52:00 +09:00
|
|
|
}
|
2018-01-16 11:51:57 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
static void print_actions(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_actions; i++) {
|
|
|
|
|
struct action_data *data = hist_data->actions[i];
|
|
|
|
|
|
2019-02-14 08:42:46 +09:00
|
|
|
if (data->action == ACTION_SNAPSHOT)
|
|
|
|
|
continue;
|
|
|
|
|
|
2019-02-14 08:42:48 +09:00
|
|
|
if (data->handler == HANDLER_ONMAX ||
|
|
|
|
|
data->handler == HANDLER_ONCHANGE)
|
2019-02-14 08:42:44 +09:00
|
|
|
track_data_print(m, hist_data, elt, data);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
static void print_action_spec(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data,
|
|
|
|
|
struct action_data *data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
if (data->action == ACTION_SAVE) {
|
|
|
|
|
for (i = 0; i < hist_data->n_save_vars; i++) {
|
|
|
|
|
seq_printf(m, "%s", hist_data->save_vars[i]->var->var.name);
|
|
|
|
|
if (i < hist_data->n_save_vars - 1)
|
|
|
|
|
seq_puts(m, ",");
|
|
|
|
|
}
|
|
|
|
|
} else if (data->action == ACTION_TRACE) {
|
2019-02-14 08:42:50 +09:00
|
|
|
if (data->use_trace_keyword)
|
|
|
|
|
seq_printf(m, "%s", data->synth_event_name);
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
for (i = 0; i < data->n_params; i++) {
|
2019-02-14 08:42:50 +09:00
|
|
|
if (i || data->use_trace_keyword)
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
seq_puts(m, ",");
|
|
|
|
|
seq_printf(m, "%s", data->params[i]);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:44 +09:00
|
|
|
static void print_track_data_spec(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data,
|
|
|
|
|
struct action_data *data)
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
{
|
2019-02-14 08:42:44 +09:00
|
|
|
if (data->handler == HANDLER_ONMAX)
|
|
|
|
|
seq_puts(m, ":onmax(");
|
2019-02-14 08:42:48 +09:00
|
|
|
else if (data->handler == HANDLER_ONCHANGE)
|
|
|
|
|
seq_puts(m, ":onchange(");
|
2019-02-14 08:42:44 +09:00
|
|
|
seq_printf(m, "%s", data->track_data.var_str);
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
seq_printf(m, ").%s(", data->action_name);
|
|
|
|
|
|
|
|
|
|
print_action_spec(m, hist_data, data);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
|
|
|
|
|
seq_puts(m, ")");
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:52:00 +09:00
|
|
|
static void print_onmatch_spec(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data,
|
|
|
|
|
struct action_data *data)
|
|
|
|
|
{
|
2019-02-14 08:42:43 +09:00
|
|
|
seq_printf(m, ":onmatch(%s.%s).", data->match_data.event_system,
|
|
|
|
|
data->match_data.event);
|
2018-01-16 11:52:00 +09:00
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
seq_printf(m, "%s(", data->action_name);
|
2018-01-16 11:52:00 +09:00
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
print_action_spec(m, hist_data, data);
|
2018-01-16 11:52:00 +09:00
|
|
|
|
|
|
|
|
seq_puts(m, ")");
|
|
|
|
|
}
|
|
|
|
|
|
2018-03-29 05:10:55 +09:00
|
|
|
static bool actions_match(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct hist_trigger_data *hist_data_test)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i, j;
|
|
|
|
|
|
|
|
|
|
if (hist_data->n_actions != hist_data_test->n_actions)
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_actions; i++) {
|
|
|
|
|
struct action_data *data = hist_data->actions[i];
|
|
|
|
|
struct action_data *data_test = hist_data_test->actions[i];
|
2019-02-14 08:42:50 +09:00
|
|
|
char *action_name, *action_name_test;
|
2018-03-29 05:10:55 +09:00
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
if (data->handler != data_test->handler)
|
|
|
|
|
return false;
|
|
|
|
|
if (data->action != data_test->action)
|
2018-03-29 05:10:55 +09:00
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
if (data->n_params != data_test->n_params)
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
for (j = 0; j < data->n_params; j++) {
|
|
|
|
|
if (strcmp(data->params[j], data_test->params[j]) != 0)
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:50 +09:00
|
|
|
if (data->use_trace_keyword)
|
|
|
|
|
action_name = data->synth_event_name;
|
|
|
|
|
else
|
|
|
|
|
action_name = data->action_name;
|
|
|
|
|
|
|
|
|
|
if (data_test->use_trace_keyword)
|
|
|
|
|
action_name_test = data_test->synth_event_name;
|
|
|
|
|
else
|
|
|
|
|
action_name_test = data_test->action_name;
|
|
|
|
|
|
|
|
|
|
if (strcmp(action_name, action_name_test) != 0)
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
if (data->handler == HANDLER_ONMATCH) {
|
2019-02-14 08:42:43 +09:00
|
|
|
if (strcmp(data->match_data.event_system,
|
|
|
|
|
data_test->match_data.event_system) != 0)
|
2018-03-29 05:10:55 +09:00
|
|
|
return false;
|
2019-02-14 08:42:43 +09:00
|
|
|
if (strcmp(data->match_data.event,
|
|
|
|
|
data_test->match_data.event) != 0)
|
2018-03-29 05:10:55 +09:00
|
|
|
return false;
|
2019-02-14 08:42:48 +09:00
|
|
|
} else if (data->handler == HANDLER_ONMAX ||
|
|
|
|
|
data->handler == HANDLER_ONCHANGE) {
|
2019-02-14 08:42:44 +09:00
|
|
|
if (strcmp(data->track_data.var_str,
|
|
|
|
|
data_test->track_data.var_str) != 0)
|
2018-03-29 05:10:55 +09:00
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
2018-01-16 11:52:00 +09:00
|
|
|
static void print_actions_spec(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_actions; i++) {
|
|
|
|
|
struct action_data *data = hist_data->actions[i];
|
|
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
if (data->handler == HANDLER_ONMATCH)
|
2018-01-16 11:52:00 +09:00
|
|
|
print_onmatch_spec(m, hist_data, data);
|
2019-02-14 08:42:48 +09:00
|
|
|
else if (data->handler == HANDLER_ONMAX ||
|
|
|
|
|
data->handler == HANDLER_ONCHANGE)
|
2019-02-14 08:42:44 +09:00
|
|
|
print_track_data_spec(m, hist_data, data);
|
2018-01-16 11:52:00 +09:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
static void destroy_field_var_hists(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_field_var_hists; i++) {
|
|
|
|
|
kfree(hist_data->field_var_hists[i]->cmd);
|
|
|
|
|
kfree(hist_data->field_var_hists[i]);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
static void destroy_hist_data(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
2018-01-16 11:51:57 +09:00
|
|
|
if (!hist_data)
|
|
|
|
|
return;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
destroy_hist_trigger_attrs(hist_data->attrs);
|
|
|
|
|
destroy_hist_fields(hist_data);
|
|
|
|
|
tracing_map_destroy(hist_data->map);
|
2018-01-16 11:51:57 +09:00
|
|
|
|
|
|
|
|
destroy_actions(hist_data);
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
destroy_field_vars(hist_data);
|
|
|
|
|
destroy_field_var_hists(hist_data);
|
2018-01-16 11:51:57 +09:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
kfree(hist_data);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int create_tracing_map_fields(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct tracing_map *map = hist_data->map;
|
|
|
|
|
struct ftrace_event_field *field;
|
|
|
|
|
struct hist_field *hist_field;
|
2018-03-28 20:48:15 +09:00
|
|
|
int i, idx = 0;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
|
|
|
|
for_each_hist_field(i, hist_data) {
|
|
|
|
|
hist_field = hist_data->fields[i];
|
|
|
|
|
if (hist_field->flags & HIST_FIELD_FL_KEY) {
|
|
|
|
|
tracing_map_cmp_fn_t cmp_fn;
|
|
|
|
|
|
|
|
|
|
field = hist_field->field;
|
|
|
|
|
|
2016-03-04 03:54:52 +09:00
|
|
|
if (hist_field->flags & HIST_FIELD_FL_STACKTRACE)
|
|
|
|
|
cmp_fn = tracing_map_cmp_none;
|
2018-01-16 11:51:45 +09:00
|
|
|
else if (!field)
|
|
|
|
|
cmp_fn = tracing_map_cmp_num(hist_field->size,
|
|
|
|
|
hist_field->is_signed);
|
2016-03-04 03:54:52 +09:00
|
|
|
else if (is_string_field(field))
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
cmp_fn = tracing_map_cmp_string;
|
|
|
|
|
else
|
|
|
|
|
cmp_fn = tracing_map_cmp_num(field->size,
|
|
|
|
|
field->is_signed);
|
2016-03-04 03:54:44 +09:00
|
|
|
idx = tracing_map_add_key_field(map,
|
|
|
|
|
hist_field->offset,
|
|
|
|
|
cmp_fn);
|
2018-01-16 11:51:49 +09:00
|
|
|
} else if (!(hist_field->flags & HIST_FIELD_FL_VAR))
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
idx = tracing_map_add_sum_field(map);
|
|
|
|
|
|
|
|
|
|
if (idx < 0)
|
|
|
|
|
return idx;
|
2018-01-16 11:51:49 +09:00
|
|
|
|
|
|
|
|
if (hist_field->flags & HIST_FIELD_FL_VAR) {
|
|
|
|
|
idx = tracing_map_add_var(map);
|
|
|
|
|
if (idx < 0)
|
|
|
|
|
return idx;
|
|
|
|
|
hist_field->var.idx = idx;
|
|
|
|
|
hist_field->var.hist_data = hist_data;
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_trigger_data *
|
|
|
|
|
create_hist_data(unsigned int map_bits,
|
|
|
|
|
struct hist_trigger_attrs *attrs,
|
2018-01-16 11:51:49 +09:00
|
|
|
struct trace_event_file *file,
|
|
|
|
|
bool remove)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
{
|
2016-03-04 03:54:50 +09:00
|
|
|
const struct tracing_map_ops *map_ops = NULL;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
struct hist_trigger_data *hist_data;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
hist_data = kzalloc(sizeof(*hist_data), GFP_KERNEL);
|
|
|
|
|
if (!hist_data)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
hist_data->attrs = attrs;
|
2018-01-16 11:51:49 +09:00
|
|
|
hist_data->remove = remove;
|
2018-01-16 11:51:56 +09:00
|
|
|
hist_data->event_file = file;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
2018-01-16 11:51:57 +09:00
|
|
|
ret = parse_actions(hist_data);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
ret = create_hist_fields(hist_data, file);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
|
|
|
|
|
|
|
|
|
ret = create_sort_keys(hist_data);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
|
|
|
|
|
2018-01-16 11:51:53 +09:00
|
|
|
map_ops = &hist_trigger_elt_data_ops;
|
2016-03-04 03:54:50 +09:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
hist_data->map = tracing_map_create(map_bits, hist_data->key_size,
|
2016-03-04 03:54:50 +09:00
|
|
|
map_ops, hist_data);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
if (IS_ERR(hist_data->map)) {
|
|
|
|
|
ret = PTR_ERR(hist_data->map);
|
|
|
|
|
hist_data->map = NULL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
ret = create_tracing_map_fields(hist_data);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
|
|
|
|
out:
|
|
|
|
|
return hist_data;
|
|
|
|
|
free:
|
|
|
|
|
hist_data->attrs = NULL;
|
|
|
|
|
|
|
|
|
|
destroy_hist_data(hist_data);
|
|
|
|
|
|
|
|
|
|
hist_data = ERR_PTR(ret);
|
|
|
|
|
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
|
2018-01-16 11:51:43 +09:00
|
|
|
struct tracing_map_elt *elt, void *rec,
|
2018-01-16 11:51:56 +09:00
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
u64 *var_ref_vals)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
{
|
2018-01-16 11:51:56 +09:00
|
|
|
struct hist_elt_data *elt_data;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
struct hist_field *hist_field;
|
2018-01-16 11:51:49 +09:00
|
|
|
unsigned int i, var_idx;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
u64 hist_val;
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
elt_data = elt->private_data;
|
|
|
|
|
elt_data->var_ref_vals = var_ref_vals;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
for_each_hist_val_field(i, hist_data) {
|
|
|
|
|
hist_field = hist_data->fields[i];
|
2018-01-16 11:51:54 +09:00
|
|
|
hist_val = hist_field->fn(hist_field, elt, rbe, rec);
|
2018-01-16 11:51:49 +09:00
|
|
|
if (hist_field->flags & HIST_FIELD_FL_VAR) {
|
|
|
|
|
var_idx = hist_field->var.idx;
|
|
|
|
|
tracing_map_set_var(elt, var_idx, hist_val);
|
|
|
|
|
continue;
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
tracing_map_update_sum(elt, i, hist_val);
|
|
|
|
|
}
|
2018-01-16 11:51:49 +09:00
|
|
|
|
|
|
|
|
for_each_hist_key_field(i, hist_data) {
|
|
|
|
|
hist_field = hist_data->fields[i];
|
|
|
|
|
if (hist_field->flags & HIST_FIELD_FL_VAR) {
|
2018-01-16 11:51:54 +09:00
|
|
|
hist_val = hist_field->fn(hist_field, elt, rbe, rec);
|
2018-01-16 11:51:49 +09:00
|
|
|
var_idx = hist_field->var.idx;
|
|
|
|
|
tracing_map_set_var(elt, var_idx, hist_val);
|
|
|
|
|
}
|
|
|
|
|
}
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
|
|
|
|
|
update_field_vars(hist_data, elt, rbe, rec);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:54 +09:00
|
|
|
static inline void add_to_key(char *compound_key, void *key,
|
|
|
|
|
struct hist_field *key_field, void *rec)
|
|
|
|
|
{
|
|
|
|
|
size_t size = key_field->size;
|
|
|
|
|
|
|
|
|
|
if (key_field->flags & HIST_FIELD_FL_STRING) {
|
|
|
|
|
struct ftrace_event_field *field;
|
|
|
|
|
|
|
|
|
|
field = key_field->field;
|
|
|
|
|
if (field->filter_type == FILTER_DYN_STRING)
|
|
|
|
|
size = *(u32 *)(rec + field->offset) >> 16;
|
|
|
|
|
else if (field->filter_type == FILTER_STATIC_STRING)
|
|
|
|
|
size = field->size;
|
|
|
|
|
|
|
|
|
|
/* ensure NULL-termination */
|
|
|
|
|
if (size > key_field->size - 1)
|
|
|
|
|
size = key_field->size - 1;
|
|
|
|
|
|
2019-02-05 06:07:24 +09:00
|
|
|
strncpy(compound_key + key_field->offset, (char *)key, size);
|
|
|
|
|
} else
|
|
|
|
|
memcpy(compound_key + key_field->offset, key, size);
|
2016-03-04 03:54:54 +09:00
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:57 +09:00
|
|
|
static void
|
|
|
|
|
hist_trigger_actions(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt, void *rec,
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
struct ring_buffer_event *rbe, void *key,
|
|
|
|
|
u64 *var_ref_vals)
|
2018-01-16 11:51:57 +09:00
|
|
|
{
|
|
|
|
|
struct action_data *data;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_actions; i++) {
|
|
|
|
|
data = hist_data->actions[i];
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
data->fn(hist_data, elt, rec, rbe, key, data, var_ref_vals);
|
2018-01-16 11:51:57 +09:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:42 +09:00
|
|
|
static void event_hist_trigger(struct event_trigger_data *data, void *rec,
|
2018-01-16 11:51:43 +09:00
|
|
|
struct ring_buffer_event *rbe)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
2016-03-04 03:54:54 +09:00
|
|
|
bool use_compound_key = (hist_data->n_keys > 1);
|
2016-03-04 03:54:52 +09:00
|
|
|
unsigned long entries[HIST_STACKTRACE_DEPTH];
|
2018-01-16 11:51:56 +09:00
|
|
|
u64 var_ref_vals[TRACING_MAP_VARS_MAX];
|
2016-03-04 03:54:44 +09:00
|
|
|
char compound_key[HIST_KEY_SIZE_MAX];
|
2018-01-16 11:51:54 +09:00
|
|
|
struct tracing_map_elt *elt = NULL;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
struct hist_field *key_field;
|
|
|
|
|
u64 field_contents;
|
|
|
|
|
void *key = NULL;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
2016-03-04 03:54:54 +09:00
|
|
|
memset(compound_key, 0, hist_data->key_size);
|
2016-03-04 03:54:44 +09:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
for_each_hist_key_field(i, hist_data) {
|
|
|
|
|
key_field = hist_data->fields[i];
|
|
|
|
|
|
2016-03-04 03:54:52 +09:00
|
|
|
if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
|
2019-04-25 18:45:13 +09:00
|
|
|
memset(entries, 0, HIST_STACKTRACE_SIZE);
|
|
|
|
|
stack_trace_save(entries, HIST_STACKTRACE_DEPTH,
|
|
|
|
|
HIST_STACKTRACE_SKIP);
|
2016-03-04 03:54:52 +09:00
|
|
|
key = entries;
|
|
|
|
|
} else {
|
2018-01-16 11:51:54 +09:00
|
|
|
field_contents = key_field->fn(key_field, elt, rbe, rec);
|
2016-03-04 03:54:54 +09:00
|
|
|
if (key_field->flags & HIST_FIELD_FL_STRING) {
|
2016-03-04 03:54:52 +09:00
|
|
|
key = (void *)(unsigned long)field_contents;
|
2016-03-04 03:54:54 +09:00
|
|
|
use_compound_key = true;
|
|
|
|
|
} else
|
2016-03-04 03:54:52 +09:00
|
|
|
key = (void *)&field_contents;
|
2016-03-04 03:54:44 +09:00
|
|
|
}
|
2016-03-04 03:54:54 +09:00
|
|
|
|
|
|
|
|
if (use_compound_key)
|
|
|
|
|
add_to_key(compound_key, key, key_field, rec);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:54 +09:00
|
|
|
if (use_compound_key)
|
2016-03-04 03:54:44 +09:00
|
|
|
key = compound_key;
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
if (hist_data->n_var_refs &&
|
|
|
|
|
!resolve_var_refs(hist_data, key, var_ref_vals, false))
|
|
|
|
|
return;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
elt = tracing_map_insert(hist_data->map, key);
|
2018-01-16 11:51:56 +09:00
|
|
|
if (!elt)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
hist_trigger_elt_update(hist_data, elt, rec, rbe, var_ref_vals);
|
2018-01-16 11:51:57 +09:00
|
|
|
|
|
|
|
|
if (resolve_var_refs(hist_data, key, var_ref_vals, true))
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
hist_trigger_actions(hist_data, elt, rec, rbe, key, var_ref_vals);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:52 +09:00
|
|
|
static void hist_trigger_stacktrace_print(struct seq_file *m,
|
|
|
|
|
unsigned long *stacktrace_entries,
|
|
|
|
|
unsigned int max_entries)
|
|
|
|
|
{
|
|
|
|
|
char str[KSYM_SYMBOL_LEN];
|
|
|
|
|
unsigned int spaces = 8;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < max_entries; i++) {
|
2019-04-10 19:28:10 +09:00
|
|
|
if (!stacktrace_entries[i])
|
2016-03-04 03:54:52 +09:00
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
seq_printf(m, "%*c", 1 + spaces, ' ');
|
|
|
|
|
sprint_symbol(str, stacktrace_entries[i]);
|
|
|
|
|
seq_printf(m, "%s\n", str);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2019-02-14 08:42:46 +09:00
|
|
|
static void hist_trigger_print_key(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data,
|
|
|
|
|
void *key,
|
|
|
|
|
struct tracing_map_elt *elt)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
{
|
|
|
|
|
struct hist_field *key_field;
|
2016-03-04 03:54:49 +09:00
|
|
|
char str[KSYM_SYMBOL_LEN];
|
2016-03-04 03:54:52 +09:00
|
|
|
bool multiline = false;
|
2017-09-23 04:58:22 +09:00
|
|
|
const char *field_name;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
unsigned int i;
|
|
|
|
|
u64 uval;
|
|
|
|
|
|
|
|
|
|
seq_puts(m, "{ ");
|
|
|
|
|
|
|
|
|
|
for_each_hist_key_field(i, hist_data) {
|
|
|
|
|
key_field = hist_data->fields[i];
|
|
|
|
|
|
|
|
|
|
if (i > hist_data->n_vals)
|
|
|
|
|
seq_puts(m, ", ");
|
|
|
|
|
|
2017-09-23 04:58:22 +09:00
|
|
|
field_name = hist_field_name(key_field, 0);
|
|
|
|
|
|
2016-03-04 03:54:48 +09:00
|
|
|
if (key_field->flags & HIST_FIELD_FL_HEX) {
|
|
|
|
|
uval = *(u64 *)(key + key_field->offset);
|
2017-09-23 04:58:22 +09:00
|
|
|
seq_printf(m, "%s: %llx", field_name, uval);
|
2016-03-04 03:54:49 +09:00
|
|
|
} else if (key_field->flags & HIST_FIELD_FL_SYM) {
|
|
|
|
|
uval = *(u64 *)(key + key_field->offset);
|
|
|
|
|
sprint_symbol_no_offset(str, uval);
|
2017-09-23 04:58:22 +09:00
|
|
|
seq_printf(m, "%s: [%llx] %-45s", field_name,
|
|
|
|
|
uval, str);
|
2016-03-04 03:54:49 +09:00
|
|
|
} else if (key_field->flags & HIST_FIELD_FL_SYM_OFFSET) {
|
|
|
|
|
uval = *(u64 *)(key + key_field->offset);
|
|
|
|
|
sprint_symbol(str, uval);
|
2017-09-23 04:58:22 +09:00
|
|
|
seq_printf(m, "%s: [%llx] %-55s", field_name,
|
|
|
|
|
uval, str);
|
2016-03-04 03:54:50 +09:00
|
|
|
} else if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
|
2018-01-16 11:51:53 +09:00
|
|
|
struct hist_elt_data *elt_data = elt->private_data;
|
|
|
|
|
char *comm;
|
|
|
|
|
|
|
|
|
|
if (WARN_ON_ONCE(!elt_data))
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
comm = elt_data->comm;
|
2016-03-04 03:54:50 +09:00
|
|
|
|
|
|
|
|
uval = *(u64 *)(key + key_field->offset);
|
2017-09-23 04:58:22 +09:00
|
|
|
seq_printf(m, "%s: %-16s[%10llu]", field_name,
|
|
|
|
|
comm, uval);
|
2016-03-04 03:54:51 +09:00
|
|
|
} else if (key_field->flags & HIST_FIELD_FL_SYSCALL) {
|
|
|
|
|
const char *syscall_name;
|
|
|
|
|
|
|
|
|
|
uval = *(u64 *)(key + key_field->offset);
|
|
|
|
|
syscall_name = get_syscall_name(uval);
|
|
|
|
|
if (!syscall_name)
|
|
|
|
|
syscall_name = "unknown_syscall";
|
|
|
|
|
|
2017-09-23 04:58:22 +09:00
|
|
|
seq_printf(m, "%s: %-30s[%3llu]", field_name,
|
|
|
|
|
syscall_name, uval);
|
2016-03-04 03:54:52 +09:00
|
|
|
} else if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
|
|
|
|
|
seq_puts(m, "stacktrace:\n");
|
|
|
|
|
hist_trigger_stacktrace_print(m,
|
|
|
|
|
key + key_field->offset,
|
|
|
|
|
HIST_STACKTRACE_DEPTH);
|
|
|
|
|
multiline = true;
|
2016-03-04 03:55:02 +09:00
|
|
|
} else if (key_field->flags & HIST_FIELD_FL_LOG2) {
|
2017-09-23 04:58:22 +09:00
|
|
|
seq_printf(m, "%s: ~ 2^%-2llu", field_name,
|
2016-03-04 03:55:02 +09:00
|
|
|
*(u64 *)(key + key_field->offset));
|
2016-03-04 03:54:48 +09:00
|
|
|
} else if (key_field->flags & HIST_FIELD_FL_STRING) {
|
2017-09-23 04:58:22 +09:00
|
|
|
seq_printf(m, "%s: %-50s", field_name,
|
2016-03-04 03:54:44 +09:00
|
|
|
(char *)(key + key_field->offset));
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
} else {
|
2016-03-04 03:54:44 +09:00
|
|
|
uval = *(u64 *)(key + key_field->offset);
|
2017-09-23 04:58:22 +09:00
|
|
|
seq_printf(m, "%s: %10llu", field_name, uval);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:52 +09:00
|
|
|
if (!multiline)
|
|
|
|
|
seq_puts(m, " ");
|
|
|
|
|
|
|
|
|
|
seq_puts(m, "}");
|
2019-02-14 08:42:46 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void hist_trigger_entry_print(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data,
|
|
|
|
|
void *key,
|
|
|
|
|
struct tracing_map_elt *elt)
|
|
|
|
|
{
|
|
|
|
|
const char *field_name;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
hist_trigger_print_key(m, hist_data, key, elt);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
|
|
|
|
seq_printf(m, " hitcount: %10llu",
|
|
|
|
|
tracing_map_read_sum(elt, HITCOUNT_IDX));
|
|
|
|
|
|
2016-03-04 03:54:43 +09:00
|
|
|
for (i = 1; i < hist_data->n_vals; i++) {
|
2017-09-23 04:58:22 +09:00
|
|
|
field_name = hist_field_name(hist_data->fields[i], 0);
|
|
|
|
|
|
2018-01-16 11:51:52 +09:00
|
|
|
if (hist_data->fields[i]->flags & HIST_FIELD_FL_VAR ||
|
|
|
|
|
hist_data->fields[i]->flags & HIST_FIELD_FL_EXPR)
|
2018-01-16 11:51:49 +09:00
|
|
|
continue;
|
|
|
|
|
|
2016-03-04 03:54:48 +09:00
|
|
|
if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) {
|
2017-09-23 04:58:22 +09:00
|
|
|
seq_printf(m, " %s: %10llx", field_name,
|
2016-03-04 03:54:48 +09:00
|
|
|
tracing_map_read_sum(elt, i));
|
|
|
|
|
} else {
|
2017-09-23 04:58:22 +09:00
|
|
|
seq_printf(m, " %s: %10llu", field_name,
|
2016-03-04 03:54:48 +09:00
|
|
|
tracing_map_read_sum(elt, i));
|
|
|
|
|
}
|
2016-03-04 03:54:43 +09:00
|
|
|
}
|
|
|
|
|
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:52:01 +09:00
|
|
|
print_actions(m, hist_data, elt);
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
seq_puts(m, "\n");
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int print_entries(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct tracing_map_sort_entry **sort_entries = NULL;
|
|
|
|
|
struct tracing_map *map = hist_data->map;
|
2016-03-09 07:17:15 +09:00
|
|
|
int i, n_entries;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
|
|
|
|
n_entries = tracing_map_sort_entries(map, hist_data->sort_keys,
|
|
|
|
|
hist_data->n_sort_keys,
|
|
|
|
|
&sort_entries);
|
|
|
|
|
if (n_entries < 0)
|
|
|
|
|
return n_entries;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < n_entries; i++)
|
|
|
|
|
hist_trigger_entry_print(m, hist_data,
|
|
|
|
|
sort_entries[i]->key,
|
|
|
|
|
sort_entries[i]->elt);
|
|
|
|
|
|
|
|
|
|
tracing_map_destroy_sort_entries(sort_entries, n_entries);
|
|
|
|
|
|
|
|
|
|
return n_entries;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:57 +09:00
|
|
|
static void hist_trigger_show(struct seq_file *m,
|
|
|
|
|
struct event_trigger_data *data, int n)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
2017-08-23 20:23:09 +09:00
|
|
|
int n_entries;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
2016-03-04 03:54:57 +09:00
|
|
|
if (n > 0)
|
|
|
|
|
seq_puts(m, "\n\n");
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
|
|
|
|
seq_puts(m, "# event histogram\n#\n# trigger info: ");
|
|
|
|
|
data->ops->print(m, data->ops, data);
|
2016-03-04 03:54:57 +09:00
|
|
|
seq_puts(m, "#\n\n");
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
|
|
|
|
hist_data = data->private_data;
|
|
|
|
|
n_entries = print_entries(m, hist_data);
|
2017-08-23 20:23:09 +09:00
|
|
|
if (n_entries < 0)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
n_entries = 0;
|
|
|
|
|
|
2019-02-14 08:42:46 +09:00
|
|
|
track_data_snapshot_print(m, hist_data);
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
seq_printf(m, "\nTotals:\n Hits: %llu\n Entries: %u\n Dropped: %llu\n",
|
|
|
|
|
(u64)atomic64_read(&hist_data->map->hits),
|
|
|
|
|
n_entries, (u64)atomic64_read(&hist_data->map->drops));
|
2016-03-04 03:54:57 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int hist_show(struct seq_file *m, void *v)
|
|
|
|
|
{
|
|
|
|
|
struct event_trigger_data *data;
|
|
|
|
|
struct trace_event_file *event_file;
|
|
|
|
|
int n = 0, ret = 0;
|
|
|
|
|
|
|
|
|
|
mutex_lock(&event_mutex);
|
|
|
|
|
|
|
|
|
|
event_file = event_file_data(m->private);
|
|
|
|
|
if (unlikely(!event_file)) {
|
|
|
|
|
ret = -ENODEV;
|
|
|
|
|
goto out_unlock;
|
|
|
|
|
}
|
|
|
|
|
|
2019-12-20 11:31:43 +09:00
|
|
|
list_for_each_entry(data, &event_file->triggers, list) {
|
2016-03-04 03:54:57 +09:00
|
|
|
if (data->cmd_ops->trigger_type == ETT_EVENT_HIST)
|
|
|
|
|
hist_trigger_show(m, data, n++);
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
out_unlock:
|
|
|
|
|
mutex_unlock(&event_mutex);
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int event_hist_open(struct inode *inode, struct file *file)
|
|
|
|
|
{
|
2019-10-12 06:22:50 +09:00
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
ret = security_locked_down(LOCKDOWN_TRACEFS);
|
|
|
|
|
if (ret)
|
|
|
|
|
return ret;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
return single_open(file, hist_show, file);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
const struct file_operations event_hist_fops = {
|
|
|
|
|
.open = event_hist_open,
|
|
|
|
|
.read = seq_read,
|
|
|
|
|
.llseek = seq_lseek,
|
|
|
|
|
.release = single_release,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
|
|
|
|
|
{
|
2017-09-23 04:58:22 +09:00
|
|
|
const char *field_name = hist_field_name(hist_field, 0);
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
if (hist_field->var.name)
|
|
|
|
|
seq_printf(m, "%s=", hist_field->var.name);
|
|
|
|
|
|
2018-03-29 05:10:53 +09:00
|
|
|
if (hist_field->flags & HIST_FIELD_FL_CPU)
|
tracing/histogram: Rename "cpu" to "common_cpu"
commit 1e3bac71c5053c99d438771fc9fa5082ae5d90aa upstream.
Currently the histogram logic allows the user to write "cpu" in as an
event field, and it will record the CPU that the event happened on.
The problem with this is that there's a lot of events that have "cpu"
as a real field, and using "cpu" as the CPU it ran on, makes it
impossible to run histograms on the "cpu" field of events.
For example, if I want to have a histogram on the count of the
workqueue_queue_work event on its cpu field, running:
># echo 'hist:keys=cpu' > events/workqueue/workqueue_queue_work/trigger
Gives a misleading and wrong result.
Change the command to "common_cpu" as no event should have "common_*"
fields as that's a reserved name for fields used by all events. And
this makes sense here as common_cpu would be a field used by all events.
Now we can even do:
># echo 'hist:keys=common_cpu,cpu if cpu < 100' > events/workqueue/workqueue_queue_work/trigger
># cat events/workqueue/workqueue_queue_work/hist
# event histogram
#
# trigger info: hist:keys=common_cpu,cpu:vals=hitcount:sort=hitcount:size=2048 if cpu < 100 [active]
#
{ common_cpu: 0, cpu: 2 } hitcount: 1
{ common_cpu: 0, cpu: 4 } hitcount: 1
{ common_cpu: 7, cpu: 7 } hitcount: 1
{ common_cpu: 0, cpu: 7 } hitcount: 1
{ common_cpu: 0, cpu: 1 } hitcount: 1
{ common_cpu: 0, cpu: 6 } hitcount: 2
{ common_cpu: 0, cpu: 5 } hitcount: 2
{ common_cpu: 1, cpu: 1 } hitcount: 4
{ common_cpu: 6, cpu: 6 } hitcount: 4
{ common_cpu: 5, cpu: 5 } hitcount: 14
{ common_cpu: 4, cpu: 4 } hitcount: 26
{ common_cpu: 0, cpu: 0 } hitcount: 39
{ common_cpu: 2, cpu: 2 } hitcount: 184
Now for backward compatibility, I added a trick. If "cpu" is used, and
the field is not found, it will fall back to "common_cpu" and work as
it did before. This way, it will still work for old programs that use
"cpu" to get the actual CPU, but if the event has a "cpu" as a field, it
will get that event's "cpu" field, which is probably what it wants
anyway.
I updated the tracefs/README to include documentation about both the
common_timestamp and the common_cpu. This way, if that text is present in
the README, then an application can know that common_cpu is supported over
just plain "cpu".
Link: https://lkml.kernel.org/r/20210721110053.26b4f641@oasis.local.home
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Fixes: 8b7622bf94a44 ("tracing: Add cpu field for hist triggers")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-22 00:00:53 +09:00
|
|
|
seq_puts(m, "common_cpu");
|
2018-01-16 11:51:56 +09:00
|
|
|
else if (field_name) {
|
2018-01-16 11:52:04 +09:00
|
|
|
if (hist_field->flags & HIST_FIELD_FL_VAR_REF ||
|
|
|
|
|
hist_field->flags & HIST_FIELD_FL_ALIAS)
|
2018-01-16 11:51:56 +09:00
|
|
|
seq_putc(m, '$');
|
2018-01-16 11:51:45 +09:00
|
|
|
seq_printf(m, "%s", field_name);
|
2018-03-29 05:10:53 +09:00
|
|
|
} else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP)
|
|
|
|
|
seq_puts(m, "common_timestamp");
|
2018-04-27 10:04:47 +09:00
|
|
|
|
|
|
|
|
if (hist_field->flags) {
|
|
|
|
|
if (!(hist_field->flags & HIST_FIELD_FL_VAR_REF) &&
|
|
|
|
|
!(hist_field->flags & HIST_FIELD_FL_EXPR)) {
|
|
|
|
|
const char *flags = get_hist_field_flags(hist_field);
|
|
|
|
|
|
|
|
|
|
if (flags)
|
|
|
|
|
seq_printf(m, ".%s", flags);
|
|
|
|
|
}
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int event_hist_trigger_print(struct seq_file *m,
|
|
|
|
|
struct event_trigger_ops *ops,
|
|
|
|
|
struct event_trigger_data *data)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
2018-01-16 11:51:49 +09:00
|
|
|
struct hist_field *field;
|
|
|
|
|
bool have_var = false;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
unsigned int i;
|
|
|
|
|
|
2016-03-04 03:54:59 +09:00
|
|
|
seq_puts(m, "hist:");
|
|
|
|
|
|
|
|
|
|
if (data->name)
|
|
|
|
|
seq_printf(m, "%s:", data->name);
|
|
|
|
|
|
|
|
|
|
seq_puts(m, "keys=");
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
|
|
|
|
for_each_hist_key_field(i, hist_data) {
|
2018-01-16 11:51:49 +09:00
|
|
|
field = hist_data->fields[i];
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
|
|
|
|
if (i > hist_data->n_vals)
|
|
|
|
|
seq_puts(m, ",");
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
if (field->flags & HIST_FIELD_FL_STACKTRACE)
|
2016-03-04 03:54:52 +09:00
|
|
|
seq_puts(m, "stacktrace");
|
|
|
|
|
else
|
2018-01-16 11:51:49 +09:00
|
|
|
hist_field_print(m, field);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
seq_puts(m, ":vals=");
|
2016-03-04 03:54:43 +09:00
|
|
|
|
|
|
|
|
for_each_hist_val_field(i, hist_data) {
|
2018-01-16 11:51:49 +09:00
|
|
|
field = hist_data->fields[i];
|
|
|
|
|
if (field->flags & HIST_FIELD_FL_VAR) {
|
|
|
|
|
have_var = true;
|
|
|
|
|
continue;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:43 +09:00
|
|
|
if (i == HITCOUNT_IDX)
|
|
|
|
|
seq_puts(m, "hitcount");
|
|
|
|
|
else {
|
|
|
|
|
seq_puts(m, ",");
|
2018-01-16 11:51:49 +09:00
|
|
|
hist_field_print(m, field);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (have_var) {
|
|
|
|
|
unsigned int n = 0;
|
|
|
|
|
|
|
|
|
|
seq_puts(m, ":");
|
|
|
|
|
|
|
|
|
|
for_each_hist_val_field(i, hist_data) {
|
|
|
|
|
field = hist_data->fields[i];
|
|
|
|
|
|
|
|
|
|
if (field->flags & HIST_FIELD_FL_VAR) {
|
|
|
|
|
if (n++)
|
|
|
|
|
seq_puts(m, ",");
|
|
|
|
|
hist_field_print(m, field);
|
|
|
|
|
}
|
2016-03-04 03:54:43 +09:00
|
|
|
}
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
|
|
|
|
seq_puts(m, ":sort=");
|
2016-03-04 03:54:45 +09:00
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_sort_keys; i++) {
|
|
|
|
|
struct tracing_map_sort_key *sort_key;
|
2018-01-16 11:51:49 +09:00
|
|
|
unsigned int idx, first_key_idx;
|
|
|
|
|
|
|
|
|
|
/* skip VAR vals */
|
|
|
|
|
first_key_idx = hist_data->n_vals - hist_data->n_vars;
|
2016-03-04 03:54:45 +09:00
|
|
|
|
|
|
|
|
sort_key = &hist_data->sort_keys[i];
|
2018-01-16 11:51:45 +09:00
|
|
|
idx = sort_key->field_idx;
|
|
|
|
|
|
2018-01-16 11:51:50 +09:00
|
|
|
if (WARN_ON(idx >= HIST_FIELDS_MAX))
|
2018-01-16 11:51:45 +09:00
|
|
|
return -EINVAL;
|
2016-03-04 03:54:45 +09:00
|
|
|
|
|
|
|
|
if (i > 0)
|
|
|
|
|
seq_puts(m, ",");
|
|
|
|
|
|
2018-01-16 11:51:45 +09:00
|
|
|
if (idx == HITCOUNT_IDX)
|
2016-03-04 03:54:45 +09:00
|
|
|
seq_puts(m, "hitcount");
|
2018-01-16 11:51:49 +09:00
|
|
|
else {
|
|
|
|
|
if (idx >= first_key_idx)
|
|
|
|
|
idx += hist_data->n_vars;
|
2016-03-04 03:54:45 +09:00
|
|
|
hist_field_print(m, hist_data->fields[idx]);
|
2018-01-16 11:51:49 +09:00
|
|
|
}
|
2016-03-04 03:54:45 +09:00
|
|
|
|
|
|
|
|
if (sort_key->descending)
|
|
|
|
|
seq_puts(m, ".descending");
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits));
|
2018-01-16 11:52:08 +09:00
|
|
|
if (hist_data->enable_timestamps)
|
|
|
|
|
seq_printf(m, ":clock=%s", hist_data->attrs->clock);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
2018-01-16 11:52:00 +09:00
|
|
|
print_actions_spec(m, hist_data);
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
if (data->filter_str)
|
|
|
|
|
seq_printf(m, " if %s", data->filter_str);
|
|
|
|
|
|
2016-03-04 03:54:46 +09:00
|
|
|
if (data->paused)
|
|
|
|
|
seq_puts(m, " [paused]");
|
|
|
|
|
else
|
|
|
|
|
seq_puts(m, " [active]");
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
|
|
|
|
seq_putc(m, '\n');
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:59 +09:00
|
|
|
static int event_hist_trigger_init(struct event_trigger_ops *ops,
|
|
|
|
|
struct event_trigger_data *data)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
|
|
|
|
|
|
|
|
|
if (!data->ref && hist_data->attrs->name)
|
|
|
|
|
save_named_trigger(hist_data->attrs->name, data);
|
|
|
|
|
|
|
|
|
|
data->ref++;
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
static void unregister_field_var_hists(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_file *file;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
char *cmd;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_field_var_hists; i++) {
|
|
|
|
|
file = hist_data->field_var_hists[i]->hist_data->event_file;
|
|
|
|
|
cmd = hist_data->field_var_hists[i]->cmd;
|
|
|
|
|
ret = event_hist_trigger_func(&trigger_hist_cmd, file,
|
|
|
|
|
"!hist", "hist", cmd);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
static void event_hist_trigger_free(struct event_trigger_ops *ops,
|
|
|
|
|
struct event_trigger_data *data)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
|
|
|
|
|
|
|
|
|
if (WARN_ON_ONCE(data->ref <= 0))
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
data->ref--;
|
|
|
|
|
if (!data->ref) {
|
2016-03-04 03:54:59 +09:00
|
|
|
if (data->name)
|
|
|
|
|
del_named_trigger(data);
|
2018-01-16 11:51:56 +09:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
trigger_data_free(data);
|
2018-01-16 11:51:56 +09:00
|
|
|
|
|
|
|
|
remove_hist_vars(hist_data);
|
|
|
|
|
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:59 +09:00
|
|
|
unregister_field_var_hists(hist_data);
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
destroy_hist_data(hist_data);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct event_trigger_ops event_hist_trigger_ops = {
|
|
|
|
|
.func = event_hist_trigger,
|
|
|
|
|
.print = event_hist_trigger_print,
|
2016-03-04 03:54:59 +09:00
|
|
|
.init = event_hist_trigger_init,
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
.free = event_hist_trigger_free,
|
|
|
|
|
};
|
|
|
|
|
|
2016-03-04 03:54:59 +09:00
|
|
|
static int event_hist_trigger_named_init(struct event_trigger_ops *ops,
|
|
|
|
|
struct event_trigger_data *data)
|
|
|
|
|
{
|
|
|
|
|
data->ref++;
|
|
|
|
|
|
|
|
|
|
save_named_trigger(data->named_data->name, data);
|
|
|
|
|
|
|
|
|
|
event_hist_trigger_init(ops, data->named_data);
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void event_hist_trigger_named_free(struct event_trigger_ops *ops,
|
|
|
|
|
struct event_trigger_data *data)
|
|
|
|
|
{
|
|
|
|
|
if (WARN_ON_ONCE(data->ref <= 0))
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
event_hist_trigger_free(ops, data->named_data);
|
|
|
|
|
|
|
|
|
|
data->ref--;
|
|
|
|
|
if (!data->ref) {
|
|
|
|
|
del_named_trigger(data);
|
|
|
|
|
trigger_data_free(data);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct event_trigger_ops event_hist_trigger_named_ops = {
|
|
|
|
|
.func = event_hist_trigger,
|
|
|
|
|
.print = event_hist_trigger_print,
|
|
|
|
|
.init = event_hist_trigger_named_init,
|
|
|
|
|
.free = event_hist_trigger_named_free,
|
|
|
|
|
};
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
static struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd,
|
|
|
|
|
char *param)
|
|
|
|
|
{
|
|
|
|
|
return &event_hist_trigger_ops;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:47 +09:00
|
|
|
static void hist_clear(struct event_trigger_data *data)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
|
|
|
|
|
2016-03-04 03:54:59 +09:00
|
|
|
if (data->name)
|
|
|
|
|
pause_named_trigger(data);
|
2016-03-04 03:54:47 +09:00
|
|
|
|
2018-08-10 04:31:48 +09:00
|
|
|
tracepoint_synchronize_unregister();
|
2016-03-04 03:54:47 +09:00
|
|
|
|
|
|
|
|
tracing_map_clear(hist_data->map);
|
|
|
|
|
|
2016-03-04 03:54:59 +09:00
|
|
|
if (data->name)
|
|
|
|
|
unpause_named_trigger(data);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool compatible_field(struct ftrace_event_field *field,
|
|
|
|
|
struct ftrace_event_field *test_field)
|
|
|
|
|
{
|
|
|
|
|
if (field == test_field)
|
|
|
|
|
return true;
|
|
|
|
|
if (field == NULL || test_field == NULL)
|
|
|
|
|
return false;
|
|
|
|
|
if (strcmp(field->name, test_field->name) != 0)
|
|
|
|
|
return false;
|
|
|
|
|
if (strcmp(field->type, test_field->type) != 0)
|
|
|
|
|
return false;
|
|
|
|
|
if (field->size != test_field->size)
|
|
|
|
|
return false;
|
|
|
|
|
if (field->is_signed != test_field->is_signed)
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
return true;
|
2016-03-04 03:54:47 +09:00
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:57 +09:00
|
|
|
static bool hist_trigger_match(struct event_trigger_data *data,
|
2016-03-04 03:54:59 +09:00
|
|
|
struct event_trigger_data *data_test,
|
|
|
|
|
struct event_trigger_data *named_data,
|
|
|
|
|
bool ignore_filter)
|
2016-03-04 03:54:57 +09:00
|
|
|
{
|
|
|
|
|
struct tracing_map_sort_key *sort_key, *sort_key_test;
|
|
|
|
|
struct hist_trigger_data *hist_data, *hist_data_test;
|
|
|
|
|
struct hist_field *key_field, *key_field_test;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
2016-03-04 03:54:59 +09:00
|
|
|
if (named_data && (named_data != data_test) &&
|
|
|
|
|
(named_data != data_test->named_data))
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
if (!named_data && is_named_trigger(data_test))
|
|
|
|
|
return false;
|
|
|
|
|
|
2016-03-04 03:54:57 +09:00
|
|
|
hist_data = data->private_data;
|
|
|
|
|
hist_data_test = data_test->private_data;
|
|
|
|
|
|
|
|
|
|
if (hist_data->n_vals != hist_data_test->n_vals ||
|
|
|
|
|
hist_data->n_fields != hist_data_test->n_fields ||
|
|
|
|
|
hist_data->n_sort_keys != hist_data_test->n_sort_keys)
|
|
|
|
|
return false;
|
|
|
|
|
|
2016-03-04 03:54:59 +09:00
|
|
|
if (!ignore_filter) {
|
|
|
|
|
if ((data->filter_str && !data_test->filter_str) ||
|
|
|
|
|
(!data->filter_str && data_test->filter_str))
|
|
|
|
|
return false;
|
|
|
|
|
}
|
2016-03-04 03:54:57 +09:00
|
|
|
|
|
|
|
|
for_each_hist_field(i, hist_data) {
|
|
|
|
|
key_field = hist_data->fields[i];
|
|
|
|
|
key_field_test = hist_data_test->fields[i];
|
|
|
|
|
|
|
|
|
|
if (key_field->flags != key_field_test->flags)
|
|
|
|
|
return false;
|
2016-03-04 03:54:59 +09:00
|
|
|
if (!compatible_field(key_field->field, key_field_test->field))
|
2016-03-04 03:54:57 +09:00
|
|
|
return false;
|
|
|
|
|
if (key_field->offset != key_field_test->offset)
|
|
|
|
|
return false;
|
2018-01-16 11:51:45 +09:00
|
|
|
if (key_field->size != key_field_test->size)
|
|
|
|
|
return false;
|
|
|
|
|
if (key_field->is_signed != key_field_test->is_signed)
|
|
|
|
|
return false;
|
2018-01-16 11:51:50 +09:00
|
|
|
if (!!key_field->var.name != !!key_field_test->var.name)
|
|
|
|
|
return false;
|
|
|
|
|
if (key_field->var.name &&
|
|
|
|
|
strcmp(key_field->var.name, key_field_test->var.name) != 0)
|
|
|
|
|
return false;
|
2016-03-04 03:54:57 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_sort_keys; i++) {
|
|
|
|
|
sort_key = &hist_data->sort_keys[i];
|
|
|
|
|
sort_key_test = &hist_data_test->sort_keys[i];
|
|
|
|
|
|
|
|
|
|
if (sort_key->field_idx != sort_key_test->field_idx ||
|
|
|
|
|
sort_key->descending != sort_key_test->descending)
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:59 +09:00
|
|
|
if (!ignore_filter && data->filter_str &&
|
2016-03-04 03:54:57 +09:00
|
|
|
(strcmp(data->filter_str, data_test->filter_str) != 0))
|
|
|
|
|
return false;
|
|
|
|
|
|
2018-03-29 05:10:55 +09:00
|
|
|
if (!actions_match(hist_data, hist_data_test))
|
|
|
|
|
return false;
|
|
|
|
|
|
2016-03-04 03:54:57 +09:00
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
|
|
|
|
|
struct event_trigger_data *data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
2016-03-04 03:54:46 +09:00
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
2016-03-04 03:54:59 +09:00
|
|
|
struct event_trigger_data *test, *named_data = NULL;
|
2019-04-02 11:30:22 +09:00
|
|
|
struct trace_array *tr = file->tr;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
int ret = 0;
|
|
|
|
|
|
2016-03-04 03:54:59 +09:00
|
|
|
if (hist_data->attrs->name) {
|
|
|
|
|
named_data = find_named_trigger(hist_data->attrs->name);
|
|
|
|
|
if (named_data) {
|
|
|
|
|
if (!hist_trigger_match(data, named_data, named_data,
|
|
|
|
|
true)) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_NAMED_MISMATCH, errpos(hist_data->attrs->name));
|
2016-03-04 03:54:59 +09:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (hist_data->attrs->name && !named_data)
|
|
|
|
|
goto new;
|
|
|
|
|
|
2019-12-20 11:31:43 +09:00
|
|
|
lockdep_assert_held(&event_mutex);
|
|
|
|
|
|
|
|
|
|
list_for_each_entry(test, &file->triggers, list) {
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
2016-03-04 03:54:59 +09:00
|
|
|
if (!hist_trigger_match(data, test, named_data, false))
|
2016-03-04 03:54:57 +09:00
|
|
|
continue;
|
2016-03-04 03:54:46 +09:00
|
|
|
if (hist_data->attrs->pause)
|
|
|
|
|
test->paused = true;
|
|
|
|
|
else if (hist_data->attrs->cont)
|
|
|
|
|
test->paused = false;
|
2016-03-04 03:54:47 +09:00
|
|
|
else if (hist_data->attrs->clear)
|
|
|
|
|
hist_clear(test);
|
2018-01-16 11:52:05 +09:00
|
|
|
else {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_TRIGGER_EEXIST, 0);
|
2016-03-04 03:54:46 +09:00
|
|
|
ret = -EEXIST;
|
2018-01-16 11:52:05 +09:00
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
}
|
2016-03-04 03:54:59 +09:00
|
|
|
new:
|
2016-03-04 03:54:47 +09:00
|
|
|
if (hist_data->attrs->cont || hist_data->attrs->clear) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_TRIGGER_ENOENT_CLEAR, 0);
|
2016-03-04 03:54:46 +09:00
|
|
|
ret = -ENOENT;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2016-06-30 09:56:00 +09:00
|
|
|
if (hist_data->attrs->pause)
|
|
|
|
|
data->paused = true;
|
|
|
|
|
|
2016-03-04 03:54:59 +09:00
|
|
|
if (named_data) {
|
|
|
|
|
data->private_data = named_data->private_data;
|
|
|
|
|
set_named_trigger_data(data, named_data);
|
|
|
|
|
data->ops = &event_hist_trigger_named_ops;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
if (data->ops->init) {
|
|
|
|
|
ret = data->ops->init(data->ops, data);
|
|
|
|
|
if (ret < 0)
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:52:08 +09:00
|
|
|
if (hist_data->enable_timestamps) {
|
|
|
|
|
char *clock = hist_data->attrs->clock;
|
|
|
|
|
|
|
|
|
|
ret = tracing_set_clock(file->tr, hist_data->attrs->clock);
|
|
|
|
|
if (ret) {
|
2019-04-02 11:30:22 +09:00
|
|
|
hist_err(tr, HIST_ERR_SET_CLOCK_FAIL, errpos(clock));
|
2018-01-16 11:52:08 +09:00
|
|
|
goto out;
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
2018-01-16 11:51:45 +09:00
|
|
|
tracing_set_time_stamp_abs(file->tr, true);
|
2018-01-16 11:52:08 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (named_data)
|
|
|
|
|
destroy_hist_data(hist_data);
|
|
|
|
|
|
|
|
|
|
ret++;
|
2018-01-16 11:51:56 +09:00
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int hist_trigger_enable(struct event_trigger_data *data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
list_add_tail_rcu(&data->list, &file->triggers);
|
|
|
|
|
|
|
|
|
|
update_cond_flag(file);
|
2018-01-16 11:51:45 +09:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
if (trace_event_trigger_enable_disable(file, 1) < 0) {
|
|
|
|
|
list_del_rcu(&data->list);
|
|
|
|
|
update_cond_flag(file);
|
|
|
|
|
ret--;
|
|
|
|
|
}
|
2018-01-16 11:51:56 +09:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
static bool have_hist_trigger_match(struct event_trigger_data *data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
|
|
|
|
struct event_trigger_data *test, *named_data = NULL;
|
|
|
|
|
bool match = false;
|
|
|
|
|
|
2019-12-20 11:31:43 +09:00
|
|
|
lockdep_assert_held(&event_mutex);
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
if (hist_data->attrs->name)
|
|
|
|
|
named_data = find_named_trigger(hist_data->attrs->name);
|
|
|
|
|
|
2019-12-20 11:31:43 +09:00
|
|
|
list_for_each_entry(test, &file->triggers, list) {
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
|
|
|
if (hist_trigger_match(data, test, named_data, false)) {
|
|
|
|
|
match = true;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return match;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
static bool hist_trigger_check_refs(struct event_trigger_data *data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
|
|
|
|
struct event_trigger_data *test, *named_data = NULL;
|
|
|
|
|
|
2019-12-20 11:31:43 +09:00
|
|
|
lockdep_assert_held(&event_mutex);
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
if (hist_data->attrs->name)
|
|
|
|
|
named_data = find_named_trigger(hist_data->attrs->name);
|
|
|
|
|
|
2019-12-20 11:31:43 +09:00
|
|
|
list_for_each_entry(test, &file->triggers, list) {
|
2018-01-16 11:51:56 +09:00
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
|
|
|
if (!hist_trigger_match(data, test, named_data, false))
|
|
|
|
|
continue;
|
|
|
|
|
hist_data = test->private_data;
|
|
|
|
|
if (check_var_refs(hist_data))
|
|
|
|
|
return true;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:57 +09:00
|
|
|
static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops,
|
|
|
|
|
struct event_trigger_data *data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
2016-03-04 03:54:59 +09:00
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
|
|
|
|
struct event_trigger_data *test, *named_data = NULL;
|
2016-03-04 03:54:57 +09:00
|
|
|
bool unregistered = false;
|
|
|
|
|
|
2019-12-20 11:31:43 +09:00
|
|
|
lockdep_assert_held(&event_mutex);
|
|
|
|
|
|
2016-03-04 03:54:59 +09:00
|
|
|
if (hist_data->attrs->name)
|
|
|
|
|
named_data = find_named_trigger(hist_data->attrs->name);
|
|
|
|
|
|
2019-12-20 11:31:43 +09:00
|
|
|
list_for_each_entry(test, &file->triggers, list) {
|
2016-03-04 03:54:57 +09:00
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
2016-03-04 03:54:59 +09:00
|
|
|
if (!hist_trigger_match(data, test, named_data, false))
|
2016-03-04 03:54:57 +09:00
|
|
|
continue;
|
|
|
|
|
unregistered = true;
|
|
|
|
|
list_del_rcu(&test->list);
|
|
|
|
|
trace_event_trigger_enable_disable(file, 0);
|
|
|
|
|
update_cond_flag(file);
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (unregistered && test->ops->free)
|
|
|
|
|
test->ops->free(test->ops, test);
|
2018-01-16 11:51:45 +09:00
|
|
|
|
|
|
|
|
if (hist_data->enable_timestamps) {
|
2018-01-16 11:51:49 +09:00
|
|
|
if (!hist_data->remove || unregistered)
|
2018-01-16 11:51:45 +09:00
|
|
|
tracing_set_time_stamp_abs(file->tr, false);
|
|
|
|
|
}
|
2016-03-04 03:54:57 +09:00
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
static bool hist_file_check_refs(struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
|
|
|
|
struct event_trigger_data *test;
|
|
|
|
|
|
2019-12-20 11:31:43 +09:00
|
|
|
lockdep_assert_held(&event_mutex);
|
|
|
|
|
|
|
|
|
|
list_for_each_entry(test, &file->triggers, list) {
|
2018-01-16 11:51:56 +09:00
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
|
|
|
hist_data = test->private_data;
|
|
|
|
|
if (check_var_refs(hist_data))
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:57 +09:00
|
|
|
static void hist_unreg_all(struct trace_event_file *file)
|
|
|
|
|
{
|
2016-06-30 09:55:59 +09:00
|
|
|
struct event_trigger_data *test, *n;
|
2018-01-16 11:51:45 +09:00
|
|
|
struct hist_trigger_data *hist_data;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
struct synth_event *se;
|
|
|
|
|
const char *se_name;
|
2016-03-04 03:54:57 +09:00
|
|
|
|
2018-11-05 18:04:01 +09:00
|
|
|
lockdep_assert_held(&event_mutex);
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
if (hist_file_check_refs(file))
|
|
|
|
|
return;
|
|
|
|
|
|
2016-06-30 09:55:59 +09:00
|
|
|
list_for_each_entry_safe(test, n, &file->triggers, list) {
|
2016-03-04 03:54:57 +09:00
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
2018-01-16 11:51:45 +09:00
|
|
|
hist_data = test->private_data;
|
2016-03-04 03:54:57 +09:00
|
|
|
list_del_rcu(&test->list);
|
|
|
|
|
trace_event_trigger_enable_disable(file, 0);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
|
|
|
|
|
se_name = trace_event_name(file->event_call);
|
|
|
|
|
se = find_synth_event(se_name);
|
|
|
|
|
if (se)
|
|
|
|
|
se->ref--;
|
|
|
|
|
|
2016-03-04 03:54:57 +09:00
|
|
|
update_cond_flag(file);
|
2018-01-16 11:51:45 +09:00
|
|
|
if (hist_data->enable_timestamps)
|
|
|
|
|
tracing_set_time_stamp_abs(file->tr, false);
|
2016-03-04 03:54:57 +09:00
|
|
|
if (test->ops->free)
|
|
|
|
|
test->ops->free(test->ops, test);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
static int event_hist_trigger_func(struct event_command *cmd_ops,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *glob, char *cmd, char *param)
|
|
|
|
|
{
|
|
|
|
|
unsigned int hist_trigger_bits = TRACING_MAP_BITS_DEFAULT;
|
|
|
|
|
struct event_trigger_data *trigger_data;
|
|
|
|
|
struct hist_trigger_attrs *attrs;
|
|
|
|
|
struct event_trigger_ops *trigger_ops;
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
struct synth_event *se;
|
|
|
|
|
const char *se_name;
|
2018-01-16 11:51:49 +09:00
|
|
|
bool remove = false;
|
2018-01-16 11:52:02 +09:00
|
|
|
char *trigger, *p;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
int ret = 0;
|
|
|
|
|
|
2018-11-05 18:04:01 +09:00
|
|
|
lockdep_assert_held(&event_mutex);
|
|
|
|
|
|
2018-01-16 11:52:05 +09:00
|
|
|
if (glob && strlen(glob)) {
|
|
|
|
|
hist_err_clear();
|
2019-04-01 08:48:16 +09:00
|
|
|
last_cmd_set(file, param);
|
2018-01-16 11:52:05 +09:00
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
if (!param)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
if (glob[0] == '!')
|
|
|
|
|
remove = true;
|
|
|
|
|
|
2018-01-16 11:52:02 +09:00
|
|
|
/*
|
|
|
|
|
* separate the trigger from the filter (k:v [if filter])
|
|
|
|
|
* allowing for whitespace in the trigger
|
|
|
|
|
*/
|
|
|
|
|
p = trigger = param;
|
|
|
|
|
do {
|
|
|
|
|
p = strstr(p, "if");
|
|
|
|
|
if (!p)
|
|
|
|
|
break;
|
|
|
|
|
if (p == param)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
if (*(p - 1) != ' ' && *(p - 1) != '\t') {
|
|
|
|
|
p++;
|
|
|
|
|
continue;
|
|
|
|
|
}
|
2018-12-19 05:33:21 +09:00
|
|
|
if (p >= param + strlen(param) - (sizeof("if") - 1) - 1)
|
2018-01-16 11:52:02 +09:00
|
|
|
return -EINVAL;
|
2018-12-19 05:33:21 +09:00
|
|
|
if (*(p + sizeof("if") - 1) != ' ' && *(p + sizeof("if") - 1) != '\t') {
|
2018-01-16 11:52:02 +09:00
|
|
|
p++;
|
|
|
|
|
continue;
|
|
|
|
|
}
|
|
|
|
|
break;
|
|
|
|
|
} while (p);
|
|
|
|
|
|
|
|
|
|
if (!p)
|
|
|
|
|
param = NULL;
|
|
|
|
|
else {
|
|
|
|
|
*(p - 1) = '\0';
|
|
|
|
|
param = strstrip(p);
|
|
|
|
|
trigger = strstrip(trigger);
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
2019-04-02 11:30:22 +09:00
|
|
|
attrs = parse_hist_trigger_attrs(file->tr, trigger);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
if (IS_ERR(attrs))
|
|
|
|
|
return PTR_ERR(attrs);
|
|
|
|
|
|
|
|
|
|
if (attrs->map_bits)
|
|
|
|
|
hist_trigger_bits = attrs->map_bits;
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
hist_data = create_hist_data(hist_trigger_bits, attrs, file, remove);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
if (IS_ERR(hist_data)) {
|
|
|
|
|
destroy_hist_trigger_attrs(attrs);
|
|
|
|
|
return PTR_ERR(hist_data);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
|
|
|
|
|
|
|
|
|
|
trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
if (!trigger_data) {
|
|
|
|
|
ret = -ENOMEM;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
goto out_free;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
|
|
|
|
|
trigger_data->count = -1;
|
|
|
|
|
trigger_data->ops = trigger_ops;
|
|
|
|
|
trigger_data->cmd_ops = cmd_ops;
|
|
|
|
|
|
|
|
|
|
INIT_LIST_HEAD(&trigger_data->list);
|
|
|
|
|
RCU_INIT_POINTER(trigger_data->filter, NULL);
|
|
|
|
|
|
|
|
|
|
trigger_data->private_data = hist_data;
|
|
|
|
|
|
2016-03-04 03:54:57 +09:00
|
|
|
/* if param is non-empty, it's supposed to be a filter */
|
|
|
|
|
if (param && cmd_ops->set_filter) {
|
|
|
|
|
ret = cmd_ops->set_filter(param, trigger_data, file);
|
|
|
|
|
if (ret < 0)
|
|
|
|
|
goto out_free;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 11:51:49 +09:00
|
|
|
if (remove) {
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
if (!have_hist_trigger_match(trigger_data, file))
|
|
|
|
|
goto out_free;
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
if (hist_trigger_check_refs(trigger_data, file)) {
|
|
|
|
|
ret = -EBUSY;
|
|
|
|
|
goto out_free;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
se_name = trace_event_name(file->event_call);
|
|
|
|
|
se = find_synth_event(se_name);
|
|
|
|
|
if (se)
|
|
|
|
|
se->ref--;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
ret = 0;
|
|
|
|
|
goto out_free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
|
|
|
|
|
/*
|
|
|
|
|
* The above returns on success the # of triggers registered,
|
|
|
|
|
* but if it didn't register any it returns zero. Consider no
|
|
|
|
|
* triggers registered a failure too.
|
|
|
|
|
*/
|
|
|
|
|
if (!ret) {
|
2016-03-04 03:54:47 +09:00
|
|
|
if (!(attrs->pause || attrs->cont || attrs->clear))
|
2016-03-04 03:54:46 +09:00
|
|
|
ret = -ENOENT;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
goto out_free;
|
|
|
|
|
} else if (ret < 0)
|
|
|
|
|
goto out_free;
|
2018-01-16 11:51:56 +09:00
|
|
|
|
|
|
|
|
if (get_named_trigger_data(trigger_data))
|
|
|
|
|
goto enable;
|
|
|
|
|
|
|
|
|
|
if (has_hist_vars(hist_data))
|
|
|
|
|
save_hist_vars(hist_data);
|
|
|
|
|
|
tracing: Refactor hist trigger action code
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.
These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined. The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.
This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.
The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible. Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.
Also, add abbreviated documentation for handlers and actions to
README.
Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-14 08:42:41 +09:00
|
|
|
ret = create_actions(hist_data);
|
2018-01-16 11:51:57 +09:00
|
|
|
if (ret)
|
|
|
|
|
goto out_unreg;
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
ret = tracing_map_init(hist_data->map);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out_unreg;
|
|
|
|
|
enable:
|
|
|
|
|
ret = hist_trigger_enable(trigger_data, file);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out_unreg;
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
se_name = trace_event_name(file->event_call);
|
|
|
|
|
se = find_synth_event(se_name);
|
|
|
|
|
if (se)
|
|
|
|
|
se->ref++;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
/* Just return zero, not the number of registered triggers */
|
|
|
|
|
ret = 0;
|
|
|
|
|
out:
|
2018-01-16 11:52:05 +09:00
|
|
|
if (ret == 0)
|
|
|
|
|
hist_err_clear();
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
return ret;
|
2018-01-16 11:51:56 +09:00
|
|
|
out_unreg:
|
|
|
|
|
cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
out_free:
|
|
|
|
|
if (cmd_ops->set_filter)
|
|
|
|
|
cmd_ops->set_filter(NULL, trigger_data, NULL);
|
|
|
|
|
|
2018-01-16 11:51:56 +09:00
|
|
|
remove_hist_vars(hist_data);
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
kfree(trigger_data);
|
|
|
|
|
|
|
|
|
|
destroy_hist_data(hist_data);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct event_command trigger_hist_cmd = {
|
|
|
|
|
.name = "hist",
|
|
|
|
|
.trigger_type = ETT_EVENT_HIST,
|
|
|
|
|
.flags = EVENT_CMD_FL_NEEDS_REC,
|
|
|
|
|
.func = event_hist_trigger_func,
|
|
|
|
|
.reg = hist_register_trigger,
|
2016-03-04 03:54:57 +09:00
|
|
|
.unreg = hist_unregister_trigger,
|
|
|
|
|
.unreg_all = hist_unreg_all,
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 03:54:42 +09:00
|
|
|
.get_trigger_ops = event_hist_get_trigger_ops,
|
|
|
|
|
.set_filter = set_trigger_filter,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
__init int register_trigger_hist_cmd(void)
|
|
|
|
|
{
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
ret = register_event_command(&trigger_hist_cmd);
|
|
|
|
|
WARN_ON(ret < 0);
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
2016-03-04 03:54:55 +09:00
|
|
|
|
|
|
|
|
static void
|
2018-01-16 11:51:42 +09:00
|
|
|
hist_enable_trigger(struct event_trigger_data *data, void *rec,
|
|
|
|
|
struct ring_buffer_event *event)
|
2016-03-04 03:54:55 +09:00
|
|
|
{
|
|
|
|
|
struct enable_trigger_data *enable_data = data->private_data;
|
|
|
|
|
struct event_trigger_data *test;
|
|
|
|
|
|
2019-12-20 11:31:43 +09:00
|
|
|
list_for_each_entry_rcu(test, &enable_data->file->triggers, list,
|
|
|
|
|
lockdep_is_held(&event_mutex)) {
|
2016-03-04 03:54:55 +09:00
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
|
|
|
if (enable_data->enable)
|
|
|
|
|
test->paused = false;
|
|
|
|
|
else
|
|
|
|
|
test->paused = true;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void
|
2018-01-16 11:51:42 +09:00
|
|
|
hist_enable_count_trigger(struct event_trigger_data *data, void *rec,
|
|
|
|
|
struct ring_buffer_event *event)
|
2016-03-04 03:54:55 +09:00
|
|
|
{
|
|
|
|
|
if (!data->count)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
if (data->count != -1)
|
|
|
|
|
(data->count)--;
|
|
|
|
|
|
2018-01-16 11:51:42 +09:00
|
|
|
hist_enable_trigger(data, rec, event);
|
2016-03-04 03:54:55 +09:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct event_trigger_ops hist_enable_trigger_ops = {
|
|
|
|
|
.func = hist_enable_trigger,
|
|
|
|
|
.print = event_enable_trigger_print,
|
|
|
|
|
.init = event_trigger_init,
|
|
|
|
|
.free = event_enable_trigger_free,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static struct event_trigger_ops hist_enable_count_trigger_ops = {
|
|
|
|
|
.func = hist_enable_count_trigger,
|
|
|
|
|
.print = event_enable_trigger_print,
|
|
|
|
|
.init = event_trigger_init,
|
|
|
|
|
.free = event_enable_trigger_free,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static struct event_trigger_ops hist_disable_trigger_ops = {
|
|
|
|
|
.func = hist_enable_trigger,
|
|
|
|
|
.print = event_enable_trigger_print,
|
|
|
|
|
.init = event_trigger_init,
|
|
|
|
|
.free = event_enable_trigger_free,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static struct event_trigger_ops hist_disable_count_trigger_ops = {
|
|
|
|
|
.func = hist_enable_count_trigger,
|
|
|
|
|
.print = event_enable_trigger_print,
|
|
|
|
|
.init = event_trigger_init,
|
|
|
|
|
.free = event_enable_trigger_free,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static struct event_trigger_ops *
|
|
|
|
|
hist_enable_get_trigger_ops(char *cmd, char *param)
|
|
|
|
|
{
|
|
|
|
|
struct event_trigger_ops *ops;
|
|
|
|
|
bool enable;
|
|
|
|
|
|
|
|
|
|
enable = (strcmp(cmd, ENABLE_HIST_STR) == 0);
|
|
|
|
|
|
|
|
|
|
if (enable)
|
|
|
|
|
ops = param ? &hist_enable_count_trigger_ops :
|
|
|
|
|
&hist_enable_trigger_ops;
|
|
|
|
|
else
|
|
|
|
|
ops = param ? &hist_disable_count_trigger_ops :
|
|
|
|
|
&hist_disable_trigger_ops;
|
|
|
|
|
|
|
|
|
|
return ops;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:57 +09:00
|
|
|
static void hist_enable_unreg_all(struct trace_event_file *file)
|
|
|
|
|
{
|
2016-06-30 09:55:59 +09:00
|
|
|
struct event_trigger_data *test, *n;
|
2016-03-04 03:54:57 +09:00
|
|
|
|
2016-06-30 09:55:59 +09:00
|
|
|
list_for_each_entry_safe(test, n, &file->triggers, list) {
|
2016-03-04 03:54:57 +09:00
|
|
|
if (test->cmd_ops->trigger_type == ETT_HIST_ENABLE) {
|
|
|
|
|
list_del_rcu(&test->list);
|
|
|
|
|
update_cond_flag(file);
|
|
|
|
|
trace_event_trigger_enable_disable(file, 0);
|
|
|
|
|
if (test->ops->free)
|
|
|
|
|
test->ops->free(test->ops, test);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 03:54:55 +09:00
|
|
|
static struct event_command trigger_hist_enable_cmd = {
|
|
|
|
|
.name = ENABLE_HIST_STR,
|
|
|
|
|
.trigger_type = ETT_HIST_ENABLE,
|
|
|
|
|
.func = event_enable_trigger_func,
|
|
|
|
|
.reg = event_enable_register_trigger,
|
|
|
|
|
.unreg = event_enable_unregister_trigger,
|
2016-03-04 03:54:57 +09:00
|
|
|
.unreg_all = hist_enable_unreg_all,
|
2016-03-04 03:54:55 +09:00
|
|
|
.get_trigger_ops = hist_enable_get_trigger_ops,
|
|
|
|
|
.set_filter = set_trigger_filter,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static struct event_command trigger_hist_disable_cmd = {
|
|
|
|
|
.name = DISABLE_HIST_STR,
|
|
|
|
|
.trigger_type = ETT_HIST_ENABLE,
|
|
|
|
|
.func = event_enable_trigger_func,
|
|
|
|
|
.reg = event_enable_register_trigger,
|
|
|
|
|
.unreg = event_enable_unregister_trigger,
|
2016-03-04 03:54:57 +09:00
|
|
|
.unreg_all = hist_enable_unreg_all,
|
2016-03-04 03:54:55 +09:00
|
|
|
.get_trigger_ops = hist_enable_get_trigger_ops,
|
|
|
|
|
.set_filter = set_trigger_filter,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static __init void unregister_trigger_hist_enable_disable_cmds(void)
|
|
|
|
|
{
|
|
|
|
|
unregister_event_command(&trigger_hist_enable_cmd);
|
|
|
|
|
unregister_event_command(&trigger_hist_disable_cmd);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
__init int register_trigger_hist_enable_disable_cmds(void)
|
|
|
|
|
{
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
ret = register_event_command(&trigger_hist_enable_cmd);
|
|
|
|
|
if (WARN_ON(ret < 0))
|
|
|
|
|
return ret;
|
|
|
|
|
ret = register_event_command(&trigger_hist_disable_cmd);
|
|
|
|
|
if (WARN_ON(ret < 0))
|
|
|
|
|
unregister_trigger_hist_enable_disable_cmds();
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
|
|
|
|
|
static __init int trace_events_hist_init(void)
|
|
|
|
|
{
|
|
|
|
|
struct dentry *entry = NULL;
|
|
|
|
|
struct dentry *d_tracer;
|
|
|
|
|
int err = 0;
|
|
|
|
|
|
2018-11-05 18:03:33 +09:00
|
|
|
err = dyn_event_register(&synth_event_ops);
|
|
|
|
|
if (err) {
|
|
|
|
|
pr_warn("Could not register synth_event_ops\n");
|
|
|
|
|
return err;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 11:51:58 +09:00
|
|
|
d_tracer = tracing_init_dentry();
|
|
|
|
|
if (IS_ERR(d_tracer)) {
|
|
|
|
|
err = PTR_ERR(d_tracer);
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
entry = tracefs_create_file("synthetic_events", 0644, d_tracer,
|
|
|
|
|
NULL, &synth_events_fops);
|
|
|
|
|
if (!entry) {
|
|
|
|
|
err = -ENODEV;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return err;
|
|
|
|
|
err:
|
|
|
|
|
pr_warn("Could not create tracefs 'synthetic_events' entry\n");
|
|
|
|
|
|
|
|
|
|
return err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
fs_initcall(trace_events_hist_init);
|