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Subject: Re: a faster way to gettimeofday? rdtsc strangeness
From: Terje Eggestad <terje.eggestad@scali.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Davide Libenzi <davidel@xmailserver.org>,
        Ben Greear <greearb@candelatech.com>,
        linux-kernel <linux-kernel@vger.kernel.org>
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Date: 07 Mar 2002 16:43:35 +0100
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On Thu, 2002-03-07 at 15:41, Alan Cox wrote:
> > If you have a CPU that begin throttling it usually cut the CPU clock in
> > half and the rdtsc counter count half a fast.
> 
> They normally adjust the STPCLK which is just fine. I've only seen a few
> laptops that do it other ways. More fun are people running mixed 300/450
> BP6 boards where the tsc varies by cpu

Can /proc/cpuinfo really be trusted in figuring out how long a cycle is?


-- 
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Terje Eggestad                  mailto:terje.eggestad@scali.no
Scali Scalable Linux Systems    http://www.scali.com

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