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Date: Fri, 29 Feb 2008 22:11:26 +1100
From: Paul Mackerras <paulus@samba.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: Alexey Zaytsev <alexey.zaytsev@gmail.com>,
       Thomas Gleixner <tglx@linutronix.de>,
       lkml <linux-kernel@vger.kernel.org>
Subject: Re: printk timestamps jumping back and forth in 2.6.25-rc.
In-Reply-To: <20080228201613.GA30999@elte.hu>
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	<20080228201315.GA30736@elte.hu>
	<20080228201613.GA30999@elte.hu>
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Ingo Molnar writes:

> * Ingo Molnar <mingo@elte.hu> wrote:
> 
> > > Anything else I can do?
> > 
> > yes, please test the patch below - does it fix the problem?
> 
> (assuming you prefer patches that build, here's an updated one below.)

Is this patch going to add overhead?

On powerpc we use the timebase register, which is synchronized across
CPUs, so if this will add unnecessary overhead, we will want to way to
turn it off on powerpc (assuming this ends up going upstream).

Paul.