[PATCH 5/5] clocksource: Consistent de-rate when marking unstable

[Peter Zijlstra]

When we mark a registered clocksource unstable the watchdog_kthread
will de-rate and re-select the clocksource. Ensure we also de-rate
when getting called on an unregistered clocksource.

Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
---
 kernel/time/clocksource.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -152,12 +152,19 @@ static void __clocksource_unstable(struc
        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);
 }