Re: [PATCH] Fix next_timer_interrupt() for hrtimer

From: Tony Lindgren
Date: Thu Feb 23 2006 - 19:38:50 EST


* john stultz <johnstul@xxxxxxxxxx> [060223 16:37]:
> On Thu, 2006-02-23 at 16:26 -0800, Tony Lindgren wrote:
> > + tv = ktime_to_timespec(event);
> > +
> > + /* Assume read xtime_lock is held, so we can't use getnstimeofday() */
> > + sec = xtime.tv_sec;
> > + nsec = xtime.tv_nsec;
> > + while (unlikely(nsec >= NSEC_PER_SEC)) {
> > + nsec -= NSEC_PER_SEC;
> > + ++sec;
> > + }
> > + tv.tv_sec = sec;
> > + tv.tv_nsec = nsec;
>
> Er, I think you should be able to nest readers. Thus getnstimeofday()
> should be safe to call. Or is the comment wrong and you are assuming a
> write lock is held?

Oops, it's a write lock as next_timer_interrupt gets called from
arch/*/time.c.

Tony
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