Date: Thu, 23 Feb 2006 16:40:49 -0800
From: Tony Lindgren <tony@atomide.com>
To: john stultz <johnstul@us.ibm.com>
Cc: linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
       Martin Schwidefsky <schwidefsky@de.ibm.com>,
       Russell King <linux@arm.linux.org.uk>, Con Kolivas <kernel@kolivas.org>
Subject: Re: [PATCH] Fix next_timer_interrupt() for hrtimer
Message-ID: <20060224004049.GD4578@atomide.com>
References: <20060224002653.GC4578@atomide.com> <1140741472.1271.64.camel@cog.beaverton.ibm.com>
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* john stultz <johnstul@us.ibm.com> [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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