Messages in this thread Patch in this message | | | Date | Thu, 1 Aug 2019 09:05:41 -0700 | From | tip-bot for Anna-Maria Gleixner <> | Subject | [tip:timers/core] itimers: Prepare for PREEMPT_RT |
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Commit-ID: cab46ec655eec1b5dbb0c17a25e19f67c539f00b Gitweb: https://git.kernel.org/tip/cab46ec655eec1b5dbb0c17a25e19f67c539f00b Author: Anna-Maria Gleixner <anna-maria@linutronix.de> AuthorDate: Wed, 31 Jul 2019 00:33:51 +0200 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Thu, 1 Aug 2019 17:46:41 +0200
itimers: Prepare for PREEMPT_RT
Use the hrtimer_cancel_wait_running() synchronization mechanism to prevent priority inversion and live locks on PREEMPT_RT.
As a benefit the retry loop gains the missing cpu_relax() on !RT.
[ tglx: Split out of combo patch ]
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190730223828.690771827@linutronix.de
--- kernel/time/itimer.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/kernel/time/itimer.c b/kernel/time/itimer.c index 02068b2d5862..9d26fd4ba4c0 100644 --- a/kernel/time/itimer.c +++ b/kernel/time/itimer.c @@ -213,6 +213,7 @@ again: /* We are sharing ->siglock with it_real_fn() */ if (hrtimer_try_to_cancel(timer) < 0) { spin_unlock_irq(&tsk->sighand->siglock); + hrtimer_cancel_wait_running(timer); goto again; } expires = timeval_to_ktime(value->it_value);
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