Commit cd2af07d authored Apr 30, 2018 by Peter Zijlstra Committed by Thomas Gleixner May 02, 2018

clocksource: Consistent de-rate when marking unstable



When a registered clocksource gets marked unstable the watchdog_kthread
will de-rate and re-select the clocksource. Ensure it also de-rates
when getting called on an unregistered clocksource.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: len.brown@intel.com
Cc: rjw@rjwysocki.net
Cc: diego.viola@gmail.com
Cc: rui.zhang@intel.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180430100344.594904898@infradead.org

parent e3b4f790

kernel/time/clocksource.c

+8 −1

Original line number	Diff line number	Diff line
		@@ -152,12 +152,19 @@ static void __clocksource_unstable(struct clocksource *cs)
		cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES \| CLOCK_SOURCE_WATCHDOG);
		cs->flags \|= CLOCK_SOURCE_UNSTABLE;

		if (list_empty(&cs->list))
		/*
		* If the clocksource is registered clocksource_watchdog_kthread() will
		* re-rate and re-select.
		*/
		if (list_empty(&cs->list)) {
		cs->rating = 0;
		return;
		}

		if (cs->mark_unstable)
		cs->mark_unstable(cs);

		/* kick clocksource_watchdog_kthread() */
		if (finished_booting)
		schedule_work(&watchdog_work);
		}