Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762867AbYFKQIs (ORCPT ); Wed, 11 Jun 2008 12:08:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760830AbYFKQIl (ORCPT ); Wed, 11 Jun 2008 12:08:41 -0400 Received: from rv-out-0506.google.com ([209.85.198.228]:10072 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762763AbYFKQIk (ORCPT ); Wed, 11 Jun 2008 12:08:40 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references:x-google-sender-auth; b=s3CvS94FGqhNK7OMe3QOf9oU1EpIu9yR1U7xACcYrfiO0mjqeAe8OPVYDv1oVIWhB5 jlACCblPBnSPjFzhXOk3QysPOhYgrm7jEjsXxgm7GKjyHklrpn2E4glT4n5lMyDsPTDa zJzGZpUzB6LYjRLH/tMDhSOoVhY4rIj24LDOw= Message-ID: <2c0942db0806110908i7d99b47ej155ae11d6d832077@mail.gmail.com> Date: Wed, 11 Jun 2008 09:08:40 -0700 From: "Ray Lee" To: "Arjan van de Ven" Subject: Re: PROBLEM: no cpu MHz in /proc/cpuinfo on 2.6.25.4-rt6 Cc: "Jan Engelhardt" , "Kok, Auke" , "solsTiCe d'Hiver" , linux-kernel@vger.kernel.org In-Reply-To: <20080611063639.5e1eea5b@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200806102152.23286.solstice.dhiver@gmail.com> <20080610131314.5f7069e6@infradead.org> <484EE71A.40002@intel.com> <20080611063639.5e1eea5b@infradead.org> X-Google-Sender-Auth: ff19fc852058cb9d Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1461 Lines: 38 On Wed, Jun 11, 2008 at 6:36 AM, Arjan van de Ven wrote: > CPU frequency is... > 1) not something that is fixed; it changes all the time Not necessarily true of setups where jackd is running. > 2) not a good indication for performance; remember the 3.4Ghz pentium4, > a 2Ghz Core2Duo outperforms it Your point only holds if jackd is somehow using this to compare performance across different cpus. It's not. > 3) something which the cpu itself barely honors (the clock stops during > idle etc etc) Again, that won't be happening when jackd is running. > Userland apps that use "cpu frequency" seem to be buggy to me, at > least I don't believe that they understand the complexities about what > this means, It doesn't appear you understand what jackd is and what lengths users will go to to configure their systems for running it smoothly and reliably. > and I don't believe that the decisions they make based on > this will be made correctly. Please go read the jackd designs slides from the 2003 presentation on the jack website [1]. The author has a clue, and is quite aware of how computers work. [1] http://lad.linuxaudio.org/events/2003_zkm/slides/paul_davis-jack/title.html -- 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/