3.12.38-rt53-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: "Paul E. McKenney" upstream commit: 18d8cb64c9c074cbe2bd677ab10fff8283abdb62 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, just before we add a timer to an empty timer wheel, 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 updates ->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 | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/timer.c b/kernel/timer.c index c3017c06f212..0ee72212b99c 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -401,6 +401,7 @@ __internal_add_timer(struct tvec_base *base, struct timer_list *timer) static void internal_add_timer(struct tvec_base *base, struct timer_list *timer) { + (void)catchup_timer_jiffies(base); __internal_add_timer(base, timer); /* * Update base->active_timers and base->next_timer -- 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/