Messages in this thread Patch in this message | | | Date | Sun, 04 Mar 2007 08:12:17 -0500 | From | Andres Salomon <> | Subject | Re: [PATCH] highres: Do not run the TIMER_SOFTIRQ after switching to highres mode |
| |
Thomas Gleixner wrote: >>> The question is, how the tick timer gets enqueued in the softirq queue. >>> Can you isolate the codepath, where this happens ? > > The TIMER_SOFTIRQ runs the hrtimers during bootup until a usable > clocksource and clock event sources are registered. The switch to high > resolution mode happens inside of the TIMER_SOFTIRQ, but runs the > softirq afterwards. That way the tick emulation timer, which was set up > in the switch to highres might be executed in the softirq context, which > is a BUG. The rbtree has not to be touched by the softirq after the > highres switch. >
And an additional request, just to make it explicit that we should not have any NO_SOFTIRQ callbacks in the tree; BUG out if we encounter such a thing.
Signed-off-by: Andres Salomon <dilinger@debian.org> diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 476cb0c..4dcdd09 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1130,6 +1130,7 @@ static inline void run_hrtimer_queue(struct hrtimer_cpu_base *cpu_base, if (base->softirq_time.tv64 <= timer->expires.tv64) break; + BUG_ON(timer->cb_mode == HRTIMER_CB_IRQSAFE_NO_SOFTIRQ); timer_stats_account_hrtimer(timer); fn = timer->function; | |