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From: Wes Felter <wesley@felter.org>
To: dingxn@ymail.com
Cc: linux-kernel@vger.kernel.org
Subject: Re: a question about p4_clockmod module on Xeon quad core processors
Date: Wed, 28 Jan 2009 15:05:45 -0600	[thread overview]
Message-ID: <4980C8A9.6090904@felter.org> (raw)
In-Reply-To: <603382.20833.qm@web59902.mail.ac4.yahoo.com>

Xiaoning Ding wrote:
> Hi list,
> 
> I have tried the p4-clockmod module in Linux kernel 2.6.29 on Xeon 5355 quad-core CPUs with no luck. It seems current p4-clockmod driver still cannot support Intel Quad core processors, right? 
> 
> I know I can also use acpi-cpufreq. It can only scale down the frequence from 2.67GHz to 2GHz. But I need some lower frequencies for some experiments.

Clock modulation is quite simple; in the past I've done it from 
userspace with /dev/cpu/*/msr or written my own module to do it. I don't 
know if I've ever tried it on quad-cores, but it worked on dual-core 
Woodcrest. (Note: I was not trying to save energy.)

Wes Felter - wesley@felter.org

  parent reply	other threads:[~2009-01-28 21:06 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-01-27 20:17 a question about p4_clockmod module on Xeon quad core processors Xiaoning Ding
2009-01-27 21:23 ` Arjan van de Ven
2009-01-29 16:12   ` Xiaoning Ding
2009-01-28 21:02 ` Dave Jones
2009-01-29  2:06   ` Xiaoning Ding
2009-01-29  2:45     ` Dave Jones
2009-01-29 16:32       ` Xiaoning Ding
2009-01-29 17:08         ` Dave Jones
2009-01-29 12:27   ` Michael Tokarev
2009-01-29 17:24     ` Dave Jones
2009-01-29 19:40       ` Xiaoning Ding
2009-01-29 19:54         ` Dave Jones
2009-01-28 21:05 ` Wes Felter [this message]
2009-01-29  2:11   ` Xiaoning Ding
2009-01-29 20:47     ` Wes Felter
2009-01-30  1:12       ` Xiaoning Ding

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