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Date: Tue, 26 Oct 2010 17:46:00 +0200 (CEST)
From: Thomas Gleixner <tglx@linutronix.de>
To: Peter Zijlstra <peterz@infradead.org>
cc: Markus Trippelsdorf <markus@trippelsdorf.de>,
        Borislav Petkov <bp@amd64.org>,
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        Ingo Molnar <mingo@elte.hu>,
        Andreas Herrmann <andreas.herrmann3@amd.com>
Subject: Re: Clocksource tsc unstable (delta = -8589361717 ns) in current
 git
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On Tue, 26 Oct 2010, Peter Zijlstra wrote:

> On Tue, 2010-10-26 at 15:58 +0200, Markus Trippelsdorf wrote:
> > > 
> > > This is strange, tsc is actually stable on your F10h revC.
> > 
> > Yes. constant_tsc is among the CPU flags. 
>  
> constant_tsc only means the TSC is not affected by cpu freq changes.
> 
> It has zero relevance to cross-cpu sync of the TSC. The clocksource
> stuff requires your TSC to be synchronous over all your CPUs.

That and not affected by C-States either.

Thanks,

	tglx