Re: [PATCH 3/3] [RFC] hrtimer: Update hrtimer base offsets each hrtimer_interrupt

From: Prarit Bhargava
Date: Thu Jul 05 2012 - 12:12:27 EST




On 07/04/2012 02:21 AM, John Stultz wrote:
> This patch introduces a new funciton which captures the
> CLOCK_MONOTONIC time, along with the CLOCK_REALTIME and
> CLOCK_BOOTTIME offsets at the same moment. This new function
> is then used in place of ktime_get() when hrtimer_interrupt()
> is expiring timers.
>
> This ensures that any changes to realtime or boottime offsets
> are noticed and stored into the per-cpu hrtimer base structures,
> prior to doing any hrtimer expiration. This should ensure that
> timers are not expired early if the offsets changes under us.
>
> This is useful in the case where clock_was_set() is called from
> atomic context and have to schedule the hrtimer base offset update
> via a timer, as it provides extra robustness in the face of any
> possible timer delay.
>
> CC: Prarit Bhargava <prarit@xxxxxxxxxx>
> CC: stable@xxxxxxxxxxxxxxx
> CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> CC: linux@xxxxxxxxxxxxxx
> Signed-off-by: John Stultz <johnstul@xxxxxxxxxx>

Acked-by: Prarit Bhargava <prarit@xxxxxxxxxx>

P.
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