kernel/sysrq, watchdog, sched/core: Reset watchdog on all CPUs while processing sysrq-w
authorAndrey Ryabinin <aryabinin@virtuozzo.com>
Thu, 9 Jun 2016 12:20:05 +0000 (15:20 +0300)
committerIngo Molnar <mingo@kernel.org>
Tue, 14 Jun 2016 10:48:38 +0000 (12:48 +0200)
commit57675cb976eff977aefb428e68e4e0236d48a9ff
tree3c61c93aabc2b6597a249492454db2ebf14d347f
parenteda8dca519269c92a0771668b3d5678792de7b78
kernel/sysrq, watchdog, sched/core: Reset watchdog on all CPUs while processing sysrq-w

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>
kernel/sched/core.c