3.12.38-rt53-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: "Paul E. McKenney" upstream commit: 16d937f880312e3f47157d4d6d6ebf7e61523378 The __run_timers() function currently steps through the list one jiffy at a time in order to update the timer wheel. However, if the timer wheel is empty, no adjustment is needed other than updating ->timer_jiffies. Therefore, if we just emptied the timer wheel, for example, by deleting the last timer, we should mark the timer wheel as being up to date. This marking will reduce (and perhaps eliminate) the jiffy-stepping that a future __run_timers() call will need to do in response to some future timer posting or migration. This commit therefore catches ->timer_jiffies for this case. Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett Acked-by: Peter Zijlstra Reviewed-by: Oleg Nesterov Reviewed-by: Steven Rostedt Tested-by: Mike Galbraith Signed-off-by: Steven Rostedt --- kernel/timer.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/timer.c b/kernel/timer.c index 763ca9af64ae..c3017c06f212 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -691,6 +691,7 @@ detach_expired_timer(struct timer_list *timer, struct tvec_base *base) if (!tbase_get_deferrable(timer->base)) base->active_timers--; base->all_timers--; + (void)catchup_timer_jiffies(base); } static int detach_if_pending(struct timer_list *timer, struct tvec_base *base, @@ -706,6 +707,7 @@ static int detach_if_pending(struct timer_list *timer, struct tvec_base *base, base->next_timer = base->timer_jiffies; } base->all_timers--; + (void)catchup_timer_jiffies(base); return 1; } -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/