[PATCH] kernel/sysrq: reset watchdog on all CPUs while processing sysrq-w

From: Andrey Ryabinin
Date: Fri May 27 2016 - 08:49:23 EST


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 softlockup.
Sometimes this doesn't work since watchdog might trigger on the other
CPU which is waiting for an IPI to proceed.

Reset watchdog on all CPUs to prevent spurious softlockup messages.

Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
---
kernel/sched/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 7f2cae4..c135eee 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5134,7 +5134,7 @@ 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:
*/
- touch_nmi_watchdog();
+ touch_all_softlockup_watchdogs();
if (!state_filter || (p->state & state_filter))
sched_show_task(p);
}
--
2.7.3