From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752053AbXC3Pjp (ORCPT ); Fri, 30 Mar 2007 11:39:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752800AbXC3Pjp (ORCPT ); Fri, 30 Mar 2007 11:39:45 -0400 Received: from gundega.hpl.hp.com ([192.6.19.190]:63746 "EHLO gundega.hpl.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752237AbXC3Pjo (ORCPT ); Fri, 30 Mar 2007 11:39:44 -0400 Date: Fri, 30 Mar 2007 07:39:37 -0800 From: Stephane Eranian To: linux-kernel@vger.kernel.org Cc: perfmon@napali.hpl.hp.com, Stephane Eranian Subject: exposing FSB clock speed in /sys Message-ID: <20070330153937.GC16059@frankl.hpl.hp.com> Reply-To: eranian@hpl.hp.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.1i Organisation: HP Labs Palo Alto Address: HP Labs, 1U-17, 1501 Page Mill road, Palo Alto, CA 94304, USA. E-mail: eranian@hpl.hp.com X-HPL-MailScanner: Found to be clean X-HPL-MailScanner-From: eranian@hpl.hp.com Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hello, It seems that the kernel does not expose the Front-Side Bus (FSN) Clock speed to user applications. I found code in the kernel dealing with frequency scaling that extracts the information for x86 processors but the value is never exposed. Knowledge the the FSB speed is very useful to monitoring tools. It is used to compute certain bus-related metrics. Looking at the code, it seems that there is no standard way of extracting the FSB speed. For each processor model, you have different MSRs. I would think that the routines in the cpufreq code could be moved out and used as the basis to expose the information somewhere in /sys. Any comments? -- -Stephane