Re: [PATCH] softlockup: fix problem with long kernel pauses fromkgdb

From: Peter Zijlstra
Date: Mon Jul 27 2009 - 16:15:57 EST


On Mon, 2009-07-27 at 15:03 -0500, Jason Wessel wrote:
>
> The fix is to simply invoke sched_clock_tick() to update "cpu sched
> clock" on exit from kgdb_handle_exception.

Is that a regular IRQ context, or is that NMI context?

> Signed-off-by: Dongdong Deng <Dongdong.Deng@xxxxxxxxxxxxx>
> Signed-off-by: Jason Wessel <jason.wessel@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxx>
> Cc: peterz@xxxxxxxxxxxxx
> ---
> kernel/softlockup.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> --- a/kernel/softlockup.c
> +++ b/kernel/softlockup.c
> @@ -118,6 +118,9 @@ void softlockup_tick(void)
> }
>
> if (touch_timestamp == 0) {
> + /* If the time stamp was touched externally make sure the
> + * scheduler tick is up to date as well */
> + sched_clock_tick();
> __touch_softlockup_watchdog();
> return;
> }
>

Aside from the funny comment style (please fix) the fix does look
sensible.
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