diff mbox series

[5.4,085/151] tick/common: Touch watchdog in tick_unfreeze() on all CPUs

Message ID 20201117122125.549453165@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg KH Nov. 17, 2020, 1:05 p.m. UTC 
From: Chunyan Zhang <zhang.lyra@gmail.com>

commit 5167c506d62dd9ffab73eba23c79b0a8845c9fe1 upstream.

Suspend to IDLE invokes tick_unfreeze() on resume. tick_unfreeze() on the
first resuming CPU resumes timekeeping, which also has the side effect of
resetting the softlockup watchdog on this CPU.

But on the secondary CPUs the watchdog is not reset in the resume /
unfreeze() path, which can result in false softlockup warnings on those
CPUs depending on the time spent in suspend.

Prevent this by clearing the softlock watchdog in the unfreeze path also
on the secondary resuming CPUs.

[ tglx: Massaged changelog ]

Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200110083902.27276-1-chunyan.zhang@unisoc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 kernel/time/tick-common.c |    2 ++
 1 file changed, 2 insertions(+)
diff mbox series

Patch

--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -11,6 +11,7 @@ 
 #include <linux/err.h>
 #include <linux/hrtimer.h>
 #include <linux/interrupt.h>
+#include <linux/nmi.h>
 #include <linux/percpu.h>
 #include <linux/profile.h>
 #include <linux/sched.h>
@@ -558,6 +559,7 @@  void tick_unfreeze(void)
 		trace_suspend_resume(TPS("timekeeping_freeze"),
 				     smp_processor_id(), false);
 	} else {
+		touch_softlockup_watchdog();
 		tick_resume_local();
 	}