Re: [PATCH 08/14] hrtimer: Allow hrtimer::function() to free the timer

From: Oleg Nesterov
Date: Tue Jun 09 2015 - 17:40:46 EST


Damn,

On 06/09, Oleg Nesterov wrote:
>
> Yes, we only have this 2nd write_seqcount_begin/end if the timer re-
> arms itself, but otherwise we do not race. If another thread does
> hrtime_start() in between we can pretend that hrtimer_active() hits
> the "inactive".
^^^^^^^^^^^^^^^

I meant,

hits the "inactive" window we can't avoid. Even if another
thread does this _before_ __run_hrtimer() clears ->running,
we can't distinguish from the case when it does this right
_after_ the timer becomes "inactive".

Oleg.

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