Subject: Re: [PATCH] Fix next_timer_interrupt() for hrtimer
From: john stultz <johnstul@us.ibm.com>
To: Tony Lindgren <tony@atomide.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>
In-Reply-To: <20060224002653.GC4578@atomide.com>
References: <20060224002653.GC4578@atomide.com>
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Date: Thu, 23 Feb 2006 16:37:52 -0800
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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?

thanks
-john


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