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 <[email protected]> Signed-off-by: Sebastian Andrzej Siewior <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> --- fs/timerfd.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/fs/timerfd.c +++ b/fs/timerfd.c @@ -471,7 +471,11 @@ static int do_timerfd_settime(int ufd, i 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); } /*
