From mboxrd@z Thu Jan 1 00:00:00 1970 From: Len Brown Subject: Re: About p4-clockmod breakage/removal Date: Tue, 13 May 2008 23:35:32 -0400 Message-ID: <200805132335.33118.lenb@kernel.org> References: <48246C3E.7010608@ceibo.fiec.espol.edu.ec> <200805132048.00653.lenb@kernel.org> <20080514005636.GA21608@srcf.ucam.org> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from hera.kernel.org ([140.211.167.34]:43061 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755650AbYENDfx (ORCPT ); Tue, 13 May 2008 23:35:53 -0400 In-Reply-To: <20080514005636.GA21608@srcf.ucam.org> Content-Disposition: inline Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Matthew Garrett Cc: cpufreq@lists.linux.org.uk, Alex =?iso-8859-1?q?Villac=ED=ADs_Lasso?= , linux-acpi@vger.kernel.org On Tuesday 13 May 2008, Matthew Garrett wrote: > On Tue, May 13, 2008 at 08:48:00PM -0400, Len Brown wrote: > > > Assuming this is a laptop with a batter, > > I'd certainly be interested if you could run BLTK > > and measure any benefit to p4-clockmod (I've never > > been able to) > > The most plausible benefit to p4-clockmod is its utility in throttling > the CPU if it would otherwise cause the system to overheat. From that > point of view, I think it's worth keeping around - especially since not > all machines expose T states via ACPI. Matthew, I'm delighted in your efforts to make Linux better, I really am. So I'm sorry that for the 3rd message in a row I have to completely disagree with you. cpufreq is not designed to manage thermals, and putting p4_clockmod underneath it to manage thermals is a mistake. There is already a well known thermal throttling interface available via ACPI and it does not need p4_clockmod to run. Passive trip points work automatically even without cpufreq being present. If they do not, then we need to fix them. p4-clockmod should have been removed from the tree over a year ago. -Len