From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261332AbVGGVIZ (ORCPT ); Thu, 7 Jul 2005 17:08:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261369AbVGGVIZ (ORCPT ); Thu, 7 Jul 2005 17:08:25 -0400 Received: from isilmar.linta.de ([213.239.214.66]:25229 "EHLO linta.de") by vger.kernel.org with ESMTP id S261332AbVGGVIY (ORCPT ); Thu, 7 Jul 2005 17:08:24 -0400 Date: Thu, 7 Jul 2005 23:08:23 +0200 From: Dominik Brodowski To: st3@riseup.net, Dave Jones , linux-kernel@vger.kernel.org, cpufreq@lists.linux.org.uk Subject: Re: enhanced intel speedstep feature was Re: speedstep-centrino on dothan Message-ID: <20050707210823.GA24774@isilmar.linta.de> Mail-Followup-To: st3@riseup.net, Dave Jones , linux-kernel@vger.kernel.org, cpufreq@lists.linux.org.uk References: <20050706112202.33d63d4d@horst.morte.male> <42CC37FD.5040708@tmr.com> <20050706211159.GF27630@redhat.com> <20050706235557.0c122d33@horst.morte.male> <20050707220027.413343d4@horst.morte.male> <20050707200648.GA29142@redhat.com> <20050707222225.5b3113e0@horst.morte.male> <20050707205117.GB10635@digitasaru.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050707205117.GB10635@digitasaru.net> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 07, 2005 at 03:51:17PM -0500, Joseph Pingenot wrote: > >Just a latest question: can be p4-clockmod used together with > >speedstep-centrino? If not, would it make any sense to patch > >speedstep-centrino to use this feature too? > > I'm a little confused. How is this different from the ACPI CPU throttling > states (/proc/acpi/processor/CPUn/limit to set, throttling to see all > T-states available)? T-states _tend_ to be utilized using chipset logic, while p4-clockmod is done in-CPU. > On my 1.5-year-old Pentium-M, frequency scaling and T-states are different > beasties, and act entirely differently. I'm currently in the process of > rewriting my governor's brain to deal with the two more intelligently. In your case, I would care about throttling. In very most cases it actually increases energy consumption, as the state being entered is technically the same to ACPI C2 (IIRC), so it is only "forced" idling and only useful if "forced" idling is needed to not need active cooling. Dominik