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From: Andi Kleen <ak@suse.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Marin Mitov <mitov@issp.bas.bg>,
	linux-kernel@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>
Subject: Re: is minimum udelay() not respected in preemptible SMP kernel-2.6.23?
Date: Thu, 8 Nov 2007 00:10:44 +0100	[thread overview]
Message-ID: <200711080010.44632.ak@suse.de> (raw)
In-Reply-To: <20071107123045.c6d4b855.akpm@linux-foundation.org>


> Ow.  Yes, from my reading delay_tsc() can return early (or after
> heat-death-of-the-universe) if the TSCs are offset and if preemption
> migrates the calling task between CPUs.
>
> I suppose a lameo fix would be to disable preemption in delay_tsc().

Yes. Can't think of any better reasonable fix.

-Andi

  reply	other threads:[~2007-11-07 23:17 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-11-07 17:21 is minimum udelay() not respected in preemptible SMP kernel-2.6.23? Marin Mitov
2007-11-07 20:30 ` Andrew Morton
2007-11-07 23:10   ` Andi Kleen [this message]
2007-11-08  0:20   ` Matt Mackall
2007-11-08  0:31     ` Andi Kleen
2007-11-08  1:03       ` Matt Mackall
2007-11-08  1:20         ` Andi Kleen
2007-11-08  2:44           ` Matt Mackall
2007-11-08 11:46       ` Avi Kivity
2007-11-08 15:10         ` Matt Mackall
2007-11-08  9:11     ` Peter Zijlstra
2007-11-08 15:43       ` Matt Mackall
2007-11-08 11:24   ` Marin Mitov

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