Commit c6db67cd authored Aug 20, 2010 by Peter Zijlstra Committed by Ingo Molnar Aug 23, 2010

watchdog: Don't throttle the watchdog



Stephane reported that when the machine locks up, the regular ticks,
which are responsible to resetting the throttle count, stop too.

Hence the NMI watchdog can end up being throttled before it reports on
the locked up state, and we end up being sad..

Cure this by having the watchdog overflow reset its own throttle count.

Reported-by: Stephane Eranian <eranian@google.com>
Tested-by: Stephane Eranian <eranian@google.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1282215916.1926.4696.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent ede1b429

kernel/watchdog.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -206,6 +206,9 @@ void watchdog_overflow_callback(struct perf_event *event, int nmi,
		struct perf_sample_data *data,
		struct pt_regs *regs)
		{
		/* Ensure the watchdog never gets throttled */
		event->hw.interrupts = 0;

		if (__get_cpu_var(watchdog_nmi_touch) == true) {
		__get_cpu_var(watchdog_nmi_touch) = false;
		return;

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