Messages in this thread Patch in this message | | | From | Julia Cartwright <> | Subject | [PATCH RT 17/22] alarmtimer: Prevent live lock in alarm_cancel() | Date | Mon, 6 Aug 2018 04:17:33 -0500 |
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
4.9.115-rt94-rc1 stable review patch. If you have any objection to the inclusion of this patch, let me know.
--- 8< --- 8< --- 8< --- If alarm_try_to_cancel() requires a retry, then depending on the priority setting the retry loop might prevent timer callback completion on RT. Prevent that by waiting for completion on RT, no change for a non RT kernel.
Cc: stable-rt@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> (cherry picked from commit 51e376c469bf05f32cb1ceb9e39d31bb92f1f6c8) Signed-off-by: Julia Cartwright <julia@ni.com> --- kernel/time/alarmtimer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index d67ef56ca9bc..61b20a656863 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -407,7 +407,7 @@ int alarm_cancel(struct alarm *alarm) int ret = alarm_try_to_cancel(alarm); if (ret >= 0) return ret; - cpu_relax(); + hrtimer_wait_for_timer(&alarm->timer); } } EXPORT_SYMBOL_GPL(alarm_cancel); -- 2.18.0
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