All of the remaining callers pass current into force_sig so
remove the task parameter to make this obvious and to make
misuse more difficult in the future.
This also makes it clear force_sig passes current into force_sig_info.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Most architectures use NR_syscalls as the #define for the number of syscalls.
We use __NR_syscalls, and then define NR_syscalls as __NR_syscalls.
__NR_syscalls is not used outside arch code, whereas NR_syscalls is. So as
NR_syscalls must be defined and __NR_syscalls does not, replace __NR_syscalls
with NR_syscalls.
Signed-off-by: Rashmica Gupta <rashmicy@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently, we may setup the MFC for isolated mode initilaisation with
the purge still active. This means that DMAs required to perform the
init do not happen.
This change clears the purge status after doing the purge, so that
the isolated init can proceed.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Currently, we use ctx->mapping_lock and ctx->switch_log->lock for the
context switch log. The mapping lock only prevents concurrent open()s,
so we require the switch_lock->lock for reads.
Since writes to the switch log buffer occur on context switches, we're
better off synchronising with the state_mutex, which is held during a
switch. Since we're serialised througout the buffer reads and writes,
we can use the state mutex to protect open and release too, and
can now kfree() the log buffer on release. This allows us to perform
the switch log notify without taking any extra locks.
Because the buffer is only present while the file is open, we can use
it to prevent multiple simultaneous openers.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Currently, spu_run ignores the npc argument for contexts created with
SPU_CREATE_NOSCHED. While this is correct for isolated contexts,
there's no need to enforce the npc restriction on non-isolated NOSCHED
contexts.
This means that NOSCHED contexts can only ever run with an entry point
of 0x0.
This change to spu_run_init allows setting of the npc (and, while we're
at it, the privcntl) for non-isolated NOSCHED contexts. This allows
us to run NOSCHED contexts from any entry point.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
According to the CBEA, the SPU dsisr is not updated for class 0
exceptions.
spu_stopped() is testing the dsisr that was passed to it from the class
0 exception handler, so we return a false positive here.
This patch cleans up the interrupt handler and erroneous tests in
spu_stopped. It also removes the fields from the csa since it is not
needed to process class 0 events.
Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
If the spu is stopping (ie, the SPU_STATUS_RUNNING bit is still set),
re-read the register to get the final stopped value.
Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
SPU class 0 & 1 exceptions may occur in parallel, so we may end up
overwriting csa.dsisr.
This change adds dedicated fields for each class to the spu and the spu
context so that fault data is not overwritten.
Signed-off-by: Luke Browning <lukebr@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
There's currently no way to tell if spu_process_callback has
returned with the state mutex held, as -EINTR may be returned
by either the syscall or the spu_acquire fail case.
Instead, just do a non-interruptible mutex_lock here.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Currently, we update the SPU master run control bit (ie,
spu_enable_spu) in spufs_run_spu before we grab the context mutex. This
can result in races with other processes accessing this context's
resources.
This change moves the spu_enable_spu to after we have acquired the
context lock.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
There are userspace instrumentation tools that need to monitor spu
context switches. This patch adds a new file called 'switch_log' to
each spufs context directory that can be used to monitor the context
switches.
Context switch in/out and exit from spu_run are monitored after the
file was first opened and can be read from it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
During spu_process callback, we release then acquire the SPU, but keep a
pointer to the local store memory. Since the context may have been
scheduled out during the callback, the ls pointer may become invalid.
This change reacquires the pointer to the context local store after
spu_acquire()-ing, so that it isn't invalidated by a context switch.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
commit 4ef11014 introduced a usage of SCHED_IDLE to detect when
a context is within spu_run.
Instead of SCHED_IDLE (which has other meaning), add a flag to
sched_flags to tell if a context should be running.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
2.6.25 has a regression where we can starve the scheduler by creating
(N_SPES+1) contexts, then running them one at a time.
The final context will never be run, as the other contexts are loaded on
the SPEs, none of which are repoted as free (ie, spu->alloc_state !=
SPU_FREE), so spu_get_idle() doesn't give us a spu to run on. Because
all of the contexts are stopped, none are descheduled by the scheduler
tick, as spusched_tick returns if spu_stopped(ctx).
This change replaces the spu_stopped() check with checking for SCHED_IDLE
in ctx->policy. We set a context's policy to SCHED_IDLE when we're not
in spu_run(). We also favour SCHED_IDLE contexts when looking for contexts
to unbind, but leave their timeslice intact for later resumption.
This patch fixes the following test in the spufs-testsuite:
tests/20-scheduler/02-yield-starvation
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Stop bits are only valid when the running bit is not set. Status bits
carry over from one invocation of spufs_run_spu() to another, so the
RUNNING bit gets added to the previous state of the register which may
have been a remote library call. In this case, it looks like another
library routine should be invoked, but the spe is actually running.
This fixes a problem with a testcase that exercises the scheduler.
Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
We don't need to update the libassist statistic with the context in a
runnable state, so do it after spu_disable_spu().
Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Fix various state_mutex leaks. The worst one was introduced by the
interrutible state_mutex conversion but there've been a few before
too. Notably spufs_wait now returns without the state_mutex held
when returning an error, which actually cleans up some code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently we only catch debug events through the 0x3fff status;
spufs_run_spu doesn't handle single-step SPE events.
This change adds a handler for conditions where the SPE is stopped due
to single-step-mode.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Make most places that use spu_acquire/spu_acquire_saved interruptible,
this allows getting out of the spufs code when e.g. pressing ctrl+c.
There are a few places where we get called e.g. from spufs teardown
routines were we can't simply err out so these are left with a comment.
For now I've also not touched the poll routines because it's open what
libspe would expect in terms of interrupted system calls.
Acked-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Change spufs_spu_run so that the context is queued directly to the
scheduler and the controlling thread advances directly to spufs_wait()
for spe errors and exceptions.
nosched contexts are treated the same as before.
Fixes from Christoph Hellwig <hch@lst.de>
Signed-off-by: Luke Browning <lukebr@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This cleans up spu_run_init so that it does all of the spu
initialization for spufs_run_spu. It initializes the spu context as
much as possible before it activates the spu and writes the runcntl
register.
Signed-off-by: Luke Browning <lukebr@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Based on original patches from
Arnd Bergmann <arnd.bergman@de.ibm.com>; and
Luke Browning <lukebr@linux.vnet.ibm.com>
Currently, spu contexts need to be loaded to the SPU in order to take
class 0 and class 1 exceptions.
This change makes the actual interrupt-handlers much simpler (ie,
set the exception information in the context save area), and defers the
handling code to the spufs_handle_class[01] functions, called from
spufs_run_spu.
This should improve the concurrency of the spu scheduling leading to
greater SPU utilization when SPUs are overcommited.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This change encapsulates the spu_privcntl_RW register so that it can
be written through backing ops. This is necessary so that spu contexts
can be initialized and queued to the scheduler in spufs_run_spu.
Signed-off-by: Luke Browning <lukebr@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add platform specific SPU run control routines to the spufs. The current
spufs implementation uses the SPU master run control bit (MFC_SR1[S]) to
control SPE execution, but the PS3 hypervisor does not support the use of
this feature.
This change adds the run control wrapper routies spu_enable_spu() and
spu_disable_spu(). The bare metal routines use the master run control
bit, and the PS3 specific routines use the priv2 run control register.
An outstanding enhancement for the PS3 would be to add a guard to check
for incorrect access to the spu problem state when the spu context is
disabled. This check could be implemented with a flag added to the spu
context that would inhibit mapping problem state pages, and a routine
to unmap spu problem state pages. When the spu is enabled with
ps3_enable_spu() the flag would be set allowing pages to be mapped,
and when the spu is disabled with ps3_disable_spu() the flag would be
cleared and mapped problem state pages would be unmapped.
Signed-off-by: Masato Noguchi <Masato.Noguchi@jp.sony.com>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
There are a few symbols used only in one file within spufs; this change
makes them static where suitable.
Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This fixes a major bug which was happening when a SPU thread advances
its execution right after being restored to a SPU. A potentially
outdated NPC value was being (re)written to the SPU.
So, spu_run_init, in this case, was either not doing anything relevant,
or breaking the execution of the SPU thread.
This fixes a common problem of losing a mailbox write when it was done
to a saved context.
Signed-off-by: Andre Detsch <adetsch@br.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently we calculate the first timeslice for every context
incorrectly - alloc_spu_context calls spu_set_timeslice before we set
ctx->prio so we always calculate the longest possible timeslice for the
lowest possible priority.
This patch makes sure to update the schedule-related fields before
calculating the timeslice and also makes sure we update the timeslice for
a non-running context when entering spu_run so a priority change affects
the context as soon as possible.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
From: Maynard Johnson <mpjohn@us.ibm.com>
This patch adds to the capability of spu_switch_event_register so that
the caller is also notified of currently active SPU tasks.
Exports spu_switch_event_register and spu_switch_event_unregister so
that OProfile can get access to the notifications provided.
Signed-off-by: Maynard Johnson <mpjohn@us.ibm.com>
Signed-off-by: Carl Love <carll@us.ibm.com>
Signed-off-by: Bob Nelson <rrnelson@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
From: Sebastian Siewior <cbe-oss-dev@ml.breakpoint.cc>
The 'file' argument is unused in spufs_run_spu(). This change removes
it.
Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
This patch exports per-context statistics in spufs as long as spu
statistics in sysfs.
It was formed by merging:
"spufs: add spu stats in sysfs" From: Christoph Hellwig
"spufs: add stat file to spufs" From: Christoph Hellwig
"spufs: fix libassist accounting" From: Jeremy Kerr
"spusched: fix spu utilization statistics" From: Luke Browning
And some adjustments by myself, after suggestions on cbe-oss-dev.
Having separate patches was making the review process harder
than it should, as we end up integrating spus and ctx statistics
accounting much more than it was on the first implementation.
Signed-off-by: Andre Detsch <adetsch@br.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
We're currently too permissive with counting libassist calls - fix the
check on the SPE stop-and-signal status.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Update scheduling information on every spu_run to allow for setting
threads to realtime priority just before running them. This requires
some slightly ugly code in spufs_run_spu because we can just update
the information unlocked if the spu is not runnable, but we need to
acquire the active_mutex when it is runnable to protect against
find_victim. This locking scheme requires opencoding
spu_acquire_runnable in spufs_run_spu which actually is a nice cleanup
all by itself.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Get rid of the scheduler workqueues that complicated things a lot to
a dedicated spu scheduler thread that gets woken by a traditional
scheduler tick. By default this scheduler tick runs a HZ * 10, aka
one spu scheduler tick for every 10 cpu ticks.
Currently the tick is not disabled when we have less context than
available spus, but I will implement this later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add a bit define from book, and replace one hex number with a
symbol, for clarity.
Signed-off-by: Sebastian Siewior <bigeasy@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch adds support for SPU single stepping. The single
step bit is set in the SPU when the current process is
being single-stepped via ptrace. The spu then stops and
returns with a specific flag set and the syscall exit code
will generate the SIGTRAP.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
- remove the spu_acquire_runnable from spu_run_init. I need to
opencode it in spufs_run_spu in the next patch
- remove various inline attributes, we don't really want to inline
long functions with multiple callsites
- cleanup return values and runcntl_write calls in spu_run_init
- use normal kernel codingstyle in spu_reacquire_runnable
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
GCC may generates inline copy loop to handle memcpy() function
instead of kernel defined memcpy(). But this inlined version of memcpy()
causes an alignment interrupt when copying from local store.
This patch uses memcpy_fromio() and memcpy_toio to copy local store
to prevent memcpy() being inlined.
Signed-off-by: Akinobu Mita <mita@fixstars.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
There is no reason for run_sema to be a struct semaphore. Changing
it to a mutex and rename it accordingly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Until now, we have always entered the spu page fault handler
with a mutex for the spu context held. This has multiple
bad side-effects:
- it becomes impossible to suspend the context during
page faults
- if an spu program attempts to access its own mmio
areas through DMA, we get an immediate livelock when
the nopage function tries to acquire the same mutex
This patch makes the page fault logic operate on a
struct spu_context instead of a struct spu, and moves it
from spu_base.c to a new file fault.c inside of spufs.
We now also need to copy the dar and dsisr contents
of the last fault into the saved context to have it
accessible in case we schedule out the context before
activating the page fault handler.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
For quite a while now spu state is protected by a simple mutex instead
of the old rw_semaphore, and this means we can simplify the locking
around spu_setup_isolated a lot.
Instead of doing an spu_release before entering spu_setup_isolated and
then calling the complicated spu_acquire_exclusive we can now simply
enter the function locked an in guaranteed runnable state, so that the
only bit of spu_acquire_exclusive that's left is the call to
spu_unmap_mappings.
Similarly there's no more need to unlock and reacquire the state_mutex
when spu_setup_isolated is done, but we can always return with the
lock held and only drop it in spu_run_init in the failure case.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
For SCHED_RR tasks we can do some really trivial timeslicing. Basically
we fire up a time for every scheduler tick that searches for a higher
or same priority thread that is on the runqueue and if there is one
context switches to it. Because we can't lock spus from timer context
we actually run this from a delayed runqueue instead of a timer.
A nice optimization would be to skip the actual priority bitmap search
when there are less contexts than physical spus available. To implement
this I need a so far unpublished patch from Andre, and it will be added
after we have that patch in.
Note that right now we only do the time slicing for SCHED_RR tasks.
The code would work for SCHED_OTHER tasks aswell, but their prio
value is defered from the one the PPU thread has at time of spu_run,
and using this for spu scheduling decisions would make the code very
unfair. SCHED_OTHER support will be enabled once we the spu scheduler
knows how to calculcate cpu_context.prio (very soon)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
There is no need to directly wake up contexts in spu_activate when
called from spu_run, so add a flag to surpress this wakeup.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Various cleanups in code surrounding the state semaphore:
- inline spu_acquire/spu_release
- cleanup spu_acquire_* and add kerneldoc comments to these functions
- remove spu_release_exclusive and replace it with spu_release
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
