From: Valdis.Kletnieks@vt.edu
To: Carl <carlr@freemail.gr>
Cc: linux-kernel@vger.kernel.org
Subject: Re: CPU eaten by unknown code
Date: Thu, 24 Dec 2009 18:53:28 -0500 [thread overview]
Message-ID: <25319.1261698808@localhost> (raw)
In-Reply-To: Your message of "Thu, 24 Dec 2009 16:12:21 +0200." <cpueatenbyunknowncode123890udwn9w8nfd9we@vt.edu>
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On Thu, 24 Dec 2009 16:12:21 +0200, Carl said:
> The loop takes 1.2 seconds for about 138 seconds.
> The loop takes 2.4 second for about 45 seconds.
> And this repeats forever.
>
> In other words, every 138 seconds something is "running" for
> 45 seconds and it takes 50% of my CPU time!
Thermal throttling? Is the fan functional? Can you monitor the CPU
temperature while running your testcase?
My second guess is something is causing a cpuspeed module to misfire and
drop the CPU to a 50% clock speed even though there's load on the system.
That one is easily testable - just do a 'grep MHz /proc/cpuinfo' during the
'fast' and 'slow' phases.
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next parent reply other threads:[~2009-12-24 23:53 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cpueatenbyunknowncode123890udwn9w8nfd9we@vt.edu>
2009-12-24 23:53 ` Valdis.Kletnieks [this message]
2009-12-24 14:12 CPU eaten by unknown code Carl
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