Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754608AbZJZGlF (ORCPT ); Mon, 26 Oct 2009 02:41:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754532AbZJZGlE (ORCPT ); Mon, 26 Oct 2009 02:41:04 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:52803 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754455AbZJZGlD (ORCPT ); Mon, 26 Oct 2009 02:41:03 -0400 Date: Mon, 26 Oct 2009 07:41:01 +0100 From: Ingo Molnar To: Krzysztof Helt Cc: Dave Jones , cpufreq@vger.kernel.org, LKLM Subject: Re: [PATCH] powernow-k6: set transition latency value so ondemand governor can be used Message-ID: <20091026064101.GB17984@elte.hu> References: <20091024172538.e2c8776b.krzysztof.h1@poczta.fm> <20091025032813.GB2475@redhat.com> <20091025194557.1d5ed484.krzysztof.h1@poczta.fm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091025194557.1d5ed484.krzysztof.h1@poczta.fm> User-Agent: Mutt/1.5.19 (2009-01-05) X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 949 Lines: 23 * Krzysztof Helt wrote: > From: Krzysztof Helt > > Set the transition latency to value smaller than CPUFREQ_ETERNAL so > governors other than "performance" work (like the "ondemand" one). > > The value is found in "AMD PowerNow! Technology Platform Design Guide for > Embedded Processors" dated December 2000 (AMD doc #24267A). There is the > answer to one of FAQs on page 40 which states that suggested complete transition > period is 200 us. Btw., would be nice to put this paragraph between '/* .. */' signs and put it into the source code - seems highly relevant when someone comes across that wonders what the magic number '200000' is. Ingo -- 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/