On Tue, 20 Nov 2007 09:46:11 +0100 Ingo Molnar <[EMAIL PROTECTED]> wrote:
> Subject: softlockup: do the wakeup from a hrtimer > From: Ingo Molnar <[EMAIL PROTECTED]> > > David Miller reported soft lockup false-positives that trigger on NOHZ > due to CPUs idling for more than 10 seconds. > > The solution is to drive the wakeup of the watchdog threads not from the > timer tick (which has no guaranteed frequency), but from the watchdog > tasks themselves. > > http://bugzilla.kernel.org/show_bug.cgi?id=9409 > > Reported-by: David Miller <[EMAIL PROTECTED]> > Signed-off-by: Ingo Molnar <[EMAIL PROTECTED]> > --- > kernel/softlockup.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > Index: linux/kernel/softlockup.c > =================================================================== > --- linux.orig/kernel/softlockup.c > +++ linux/kernel/softlockup.c > @@ -100,10 +100,6 @@ void softlockup_tick(void) > > now = get_timestamp(this_cpu); > > - /* Wake up the high-prio watchdog task every second: */ > - if (now > (touch_timestamp + 1)) > - wake_up_process(per_cpu(watchdog_task, this_cpu)); > - > /* Warn about unreasonable 10+ seconds delays: */ > if (now <= (touch_timestamp + softlockup_thresh)) > return; > @@ -141,7 +137,7 @@ static int watchdog(void *__bind_cpu) > while (!kthread_should_stop()) { > set_current_state(TASK_INTERRUPTIBLE); > touch_softlockup_watchdog(); > - schedule(); > + msleep(1000); > } > > return 0; I think you wanted msleep_interruptible() there to avoid contributing to load average? The set_current_state() can go away. This will introduce an up-to-one-second delay in responding to kthread_should_stop(). Is that bad? - 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/
