| Date | Wed, 31 Jul 2019 00:33:51 +0200 | From | Thomas Gleixner <> | Subject | [patch 3/7] itimers: Prepare for PREEMPT_RT |
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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> --- kernel/time/itimer.c | 1 + 1 file changed, 1 insertion(+)
--- a/kernel/time/itimer.c +++ b/kernel/time/itimer.c @@ -213,6 +213,7 @@ int do_setitimer(int which, struct itime /* 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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