On Tue, Apr 30, 2013 at 07:09:48PM +0200, Sebastian Andrzej Siewior wrote:
> Now, the time jump on the other hand is the real issue here and is
> RT-only. It looks like we get a big number of timer updates via
> tick_do_update_jiffies64() because according to ktime_get() that much
> time really passed by.
>
> The sollution seems as simple as
>
> From c27eb2e0ab0b5acd96a4b62288976f1b72789b3e Mon Sep 17 00:00:00 2001
> From: Sebastian Andrzej Siewior <bige...@linutronix.de>
> Date: Tue, 30 Apr 2013 18:53:55 +0200
> Subject: [PATCH] time/timekeeping: shadow tk->cycle_last together with
> clock->cycle_last
>
> Commit ("timekeeping: Store cycle_last value in timekeeper struct as
> well") introduced a tk-> based cycle_last values which needs to be reset
> on resume path as well or else ktime_get() will think that time
> increased a lot.
>
> Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
> ---
> kernel/time/timekeeping.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
> index 99f943b..688817f 100644
> --- a/kernel/time/timekeeping.c
> +++ b/kernel/time/timekeeping.c
> @@ -777,6 +777,7 @@ static void timekeeping_resume(void)
> }
> /* re-base the last cycle value */
> tk->clock->cycle_last = tk->clock->read(tk->clock);
> + tk->cycle_last = tk->clock->cycle_last;
> tk->ntp_error = 0;
> timekeeping_suspended = 0;
> timekeeping_update(tk, false, true);
Didn't tlgx fix a similar issue upstream already?
77c675ba18836.
--
Regards/Gruss,
Boris.
Sent from a fat crate under my desk. Formatting is fine.
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