On Sun, 13 Mar 2005, Oleg Nesterov wrote: > I suspect that del_timer_sync() in its current form is racy. > > CPU 0 CPU 1 > > __run_timers() sets timer->base = NULL > > del_timer_sync() starts, calls > del_timer(), it returns > because timer->base == NULL. > > waits until the run is complete: > while > (base->running_timer == timer) > > preempt_check_resched(); > > calls schedule(), or long > interrupt happens. > > timer reschedules itself, __run_timers() > exits. > > base->running_timer == NULL, > end of loop. > > next timer interrupt, __run_timers() picks > this timer again, sets timer->base = NULL > > if (timer_pending(timer)) > // no, timer->base == NULL
timer->base is != NULL because the timer has rescheduled itself. __mod_timer sets timer->bBase > goto del_again; > // not taken Yes it is taken! > > del_timer_sync() returns > > timer runs. Nope. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
