From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764272AbXHARu3 (ORCPT ); Wed, 1 Aug 2007 13:50:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758868AbXHARuV (ORCPT ); Wed, 1 Aug 2007 13:50:21 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:59280 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756346AbXHARuU (ORCPT ); Wed, 1 Aug 2007 13:50:20 -0400 Date: Wed, 1 Aug 2007 19:50:04 +0200 From: Ingo Molnar To: Linus Torvalds Cc: Andi Kleen , Roman Zippel , Mike Galbraith , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: CFS review Message-ID: <20070801175004.GA17936@elte.hu> References: <1184302024.6709.11.camel@Homer.simpson.net> <1184389456.6632.13.camel@Homer.simpson.net> <20070801071230.GA16375@elte.hu> <20070801150742.GA23670@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.14 (2007-02-12) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.1.7-deb -1.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Linus Torvalds wrote: > On Wed, 1 Aug 2007, Andi Kleen wrote: > > > Ingo Molnar writes: > > > > > thanks. Just to make sure, while you said that your TSC was off on that > > > laptop, the bootup log of yours suggests a working TSC: > > > > > > Time: tsc clocksource has been installed. > > > > Standard kernels often disable the TSC later after running a bit > > with it (e.g. on any cpufreq change without p state invariant TSC) > > I assume that what Roman hit was that he had explicitly disabled the > TSC because of TSC instability with the "notsc" kernel command line. > Which disabled is *entirely*. but that does not appear to be the case, the debug info i got from Roman includes the following boot options: Kernel command line: auto BOOT_IMAGE=2.6.23-rc1-git9 ro root=306 there's no "notsc" option there. Andi's theory cannot be true either, Roman's debug info also shows this /proc//sched data: clock-delta : 95 that means that sched_clock() is in high-res mode, the TSC is alive and kicking and a sched_clock() call took 95 nanoseconds. Roman, could you please help us with this mystery? Ingo