watchdog: introduce the proc_watchdog_update() function

This series introduces a separate handler for each watchdog parameter in
/proc/sys/kernel.  The separate handlers need a common function that they
can call to update the run state of the lockup detectors, or to have the
lockup detectors use a new sample period.

Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ulrich Obergfell 2015-04-14 15:43:58 -07:00 committed by Linus Torvalds
parent 84d56e66b9
commit a0c9cbb93d
1 changed files with 23 additions and 0 deletions

View File

@ -678,6 +678,29 @@ static void watchdog_disable_all_cpus(void)
}
}
/*
* Update the run state of the lockup detectors.
*/
static int proc_watchdog_update(void)
{
int err = 0;
/*
* Watchdog threads won't be started if they are already active.
* The 'watchdog_running' variable in watchdog_*_all_cpus() takes
* care of this. If those threads are already active, the sample
* period will be updated and the lockup detectors will be enabled
* or disabled 'on the fly'.
*/
if (watchdog_enabled && watchdog_thresh)
err = watchdog_enable_all_cpus(true);
else
watchdog_disable_all_cpus();
return err;
}
/*
* proc handler for /proc/sys/kernel/nmi_watchdog,watchdog_thresh
*/