From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Renninger Subject: Re: About p4-clockmod breakage/removal Date: Wed, 14 May 2008 14:49:18 +0200 Message-ID: <1210769358.21269.21.camel@queen.suse.de> References: <48246C3E.7010608@ceibo.fiec.espol.edu.ec> <200805132048.00653.lenb@kernel.org> <20080514005636.GA21608@srcf.ucam.org> <1210764974.29724.181.camel@queen.suse.de> <20080514114215.GA31135@srcf.ucam.org> Reply-To: trenn@suse.de Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from ns.suse.de ([195.135.220.2]:57744 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761791AbYENMtU (ORCPT ); Wed, 14 May 2008 08:49:20 -0400 In-Reply-To: <20080514114215.GA31135@srcf.ucam.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Matthew Garrett Cc: Len Brown , cpufreq@lists.linux.org.uk, Alex =?ISO-8859-1?Q?Villac=ED=ADs?= Lasso , linux-acpi@vger.kernel.org On Wed, 2008-05-14 at 12:42 +0100, Matthew Garrett wrote: > On Wed, May 14, 2008 at 01:36:14PM +0200, Thomas Renninger wrote: > > > Also there is another interface via mce: > > arch/x86/kernel/cpu/mcheck/therm_throt.c > > > > AFAIK this should be implemented in (all?) P4s, but Intel people should > > know for sure. > > Hm. The MCE interface is only for reporting, rather than control. Do you > know if it's possible to set the temperature at which the CPU will start > its own throttling? That would potentially be more straightforward. AFAIK there is not much to control from OS side. All you get is an event, or better an exception, that BIOS detected too high temperatures on the CPU and that your CPU is currently not running at full speed. The p4 parts seem to sit here: arch/x86/kernel/cpu/mcheck/p4.c You might find a hack to modify this, by reading P4 (this seem to sit in the CPU itself?) or chipset specs. But again, is it worth it for a P4 where no power saving capabilities are present anyway? Thomas