Re: [patch-rt] hotplug, hrtimer: Migrate expired/deferred timers during cpu offline

From: Sebastian Andrzej Siewior
Date: Thu Aug 17 2017 - 13:17:28 EST


On 2017-08-17 18:50:42 [+0200], To Mike Galbraith wrote:
> __remove_hrtimer() shouldn't be required because it has been done
> already. It should be enough to just list_splice() one list to the
> other and raise the softirq afterwards.

Mike, can you check this please:

diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 55839ff2bba6..4b9264e0d363 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -1802,6 +1802,11 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
*/
enqueue_hrtimer(timer, new_base);
}
+#ifdef CONFIG_PREEMPT_RT_BASE
+ list_splice_tail(&old_base->expired, &new_base->expired);
+ if (!list_empty(&new_base->expired))
+ raise_softirq_irqoff(HRTIMER_SOFTIRQ);
+#endif
}

int hrtimers_dead_cpu(unsigned int scpu)
--
2.13.2

Sebastian