redonkable
/
remarkable-linux
1
0
Fork 0
Code Releases Activity

kernel/sysrq, watchdog, sched/core: Reset watchdog on all CPUs while processing sysrq-w 

[ Upstream commit 57675cb976 ]

Lengthy output of sysrq-w may take a lot of time on slow serial console.

Currently we reset NMI-watchdog on the current CPU to avoid spurious
lockup messages. Sometimes this doesn't work since softlockup watchdog
might trigger on another CPU which is waiting for an IPI to proceed.
We reset softlockup watchdogs on all CPUs, but we do this only after
listing all tasks, and this may be too late on a busy system.

So, reset watchdogs CPUs earlier, in for_each_process_thread() loop.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1465474805-14641-1-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
wifi-calibration
Andrey Ryabinin 2016-06-09 15:20:05 +03:00 committed by Sasha Levin
parent c5ffc99b6e
commit 9f67dcf663
1 changed files with 4 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
kernel/sched/core.c
View File

@ -4568,14 +4568,16 @@ void show_state_filter(unsigned long state_filter)
/*
* reset the NMI-timeout, listing all files on a slow
* console might take a lot of time:
* Also, reset softlockup watchdogs on all CPUs, because
* another CPU might be blocked waiting for us to process
* an IPI.
*/
touch_nmi_watchdog();
touch_all_softlockup_watchdogs();
if (!state_filter || (p->state & state_filter))
sched_show_task(p);
}
touch_all_softlockup_watchdogs();
#ifdef CONFIG_SCHED_DEBUG
sysrq_sched_debug_show();
#endif