From b9c3032277f756e73f6c673419dc414155e04e46 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 3 Feb 2010 18:08:52 +0100 Subject: hrtimer, softirq: Fix hrtimer->softirq trampoline hrtimers callbacks are always done from hardirq context, either the jiffy tick interrupt or the hrtimer device interrupt. [ there is currently one exception that can still call a hrtimer callback from softirq, but even in that case this will still work correctly. ] Reported-by: Wei Yongjun Signed-off-by: Peter Zijlstra Cc: Yury Polyanskiy Tested-by: Wei Yongjun Acked-by: David S. Miller LKML-Reference: <1265120401.24455.306.camel@laptop> Signed-off-by: Thomas Gleixner --- kernel/softirq.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) diff --git a/kernel/softirq.c b/kernel/softirq.c index a09502e2ef7..7c1a67ef027 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -500,22 +500,17 @@ EXPORT_SYMBOL(tasklet_kill); */ /* - * The trampoline is called when the hrtimer expires. If this is - * called from the hrtimer interrupt then we schedule the tasklet as - * the timer callback function expects to run in softirq context. If - * it's called in softirq context anyway (i.e. high resolution timers - * disabled) then the hrtimer callback is called right away. + * The trampoline is called when the hrtimer expires. It schedules a tasklet + * to run __tasklet_hrtimer_trampoline() which in turn will call the intended + * hrtimer callback, but from softirq context. */ static enum hrtimer_restart __hrtimer_tasklet_trampoline(struct hrtimer *timer) { struct tasklet_hrtimer *ttimer = container_of(timer, struct tasklet_hrtimer, timer); - if (hrtimer_is_hres_active(timer)) { - tasklet_hi_schedule(&ttimer->tasklet); - return HRTIMER_NORESTART; - } - return ttimer->function(timer); + tasklet_hi_schedule(&ttimer->tasklet); + return HRTIMER_NORESTART; } /* -- cgit v1.2.3-70-g09d2