Messages in this thread Patch in this message | | | Date | Thu, 1 Aug 2019 09:04:53 -0700 | From | tip-bot for Anna-Maria Gleixner <> | Subject | [tip:timers/core] timerfd: Prepare for PREEMPT_RT |
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Commit-ID: 4da1306fb920a267b5ea21ee15cd771c7bc09cc6 Gitweb: https://git.kernel.org/tip/4da1306fb920a267b5ea21ee15cd771c7bc09cc6 Author: Anna-Maria Gleixner <anna-maria@linutronix.de> AuthorDate: Wed, 31 Jul 2019 00:33:50 +0200 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Thu, 1 Aug 2019 17:46:41 +0200
timerfd: Prepare for PREEMPT_RT
Use the hrtimer_cancel_wait_running() synchronization mechanism to prevent priority inversion and live locks on PREEMPT_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/20190730223828.600085866@linutronix.de
--- fs/timerfd.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/timerfd.c b/fs/timerfd.c index 6a6fc8aa1de7..48305ba41e3c 100644 --- a/fs/timerfd.c +++ b/fs/timerfd.c @@ -471,7 +471,11 @@ static int do_timerfd_settime(int ufd, int flags, break; } spin_unlock_irq(&ctx->wqh.lock); - cpu_relax(); + + if (isalarm(ctx)) + hrtimer_cancel_wait_running(&ctx->t.alarm.timer); + else + hrtimer_cancel_wait_running(&ctx->t.tmr); } /*
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