Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760254AbZA1VG3 (ORCPT ); Wed, 28 Jan 2009 16:06:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759050AbZA1VGA (ORCPT ); Wed, 28 Jan 2009 16:06:00 -0500 Received: from e35.co.us.ibm.com ([32.97.110.153]:59707 "EHLO e35.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758553AbZA1VF7 (ORCPT ); Wed, 28 Jan 2009 16:05:59 -0500 Message-ID: <4980C8A9.6090904@felter.org> Date: Wed, 28 Jan 2009 15:05:45 -0600 From: Wes Felter User-Agent: Thunderbird 2.0.0.18 (Macintosh/20081105) MIME-Version: 1.0 To: dingxn@ymail.com CC: linux-kernel@vger.kernel.org Subject: Re: a question about p4_clockmod module on Xeon quad core processors References: <603382.20833.qm@web59902.mail.ac4.yahoo.com> In-Reply-To: <603382.20833.qm@web59902.mail.ac4.yahoo.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 926 Lines: 18 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/