Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760718AbXEYIcO (ORCPT ); Fri, 25 May 2007 04:32:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752014AbXEYIcB (ORCPT ); Fri, 25 May 2007 04:32:01 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:50167 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751860AbXEYIcA (ORCPT ); Fri, 25 May 2007 04:32:00 -0400 Date: Fri, 25 May 2007 10:31:53 +0200 From: Ingo Molnar To: William Lee Irwin III Cc: Andi Kleen , Satyam Sharma , Andrew Morton , linux-kernel@vger.kernel.org, Peter Zijlstra Subject: Re: [patch] i386, numaq: enable TSCs again Message-ID: <20070525083153.GA27236@elte.hu> References: <20070525071005.GA6431@elte.hu> <20070525073158.GB8094@one.firstfloor.org> <20070525073957.GA15207@elte.hu> <20070525074316.GA16821@elte.hu> <20070525074915.GA18400@elte.hu> <20070525075446.GA20140@elte.hu> <20070525080827.GA22399@elte.hu> <20070525081944.GZ31925@holomorphy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070525081944.GZ31925@holomorphy.com> User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.0.3 -2.0 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 Content-Length: 843 Lines: 22 * William Lee Irwin III wrote: > > Andi, Andrew, do you remember why we disabled TSCs on NUMAQ? It was > > slightly async between CPUs, right? In that case we should try the > > patch below. > > I remember. It was far beyond "slightly async;" they would drift > minutes apart during reasonable amounts of uptime, though it would > take at least several days to drift so far (I don't recall how long it > took). yes, that's what i meant under 'slightly async'. Some AMD CPUs are like that too and sched_clock() now handles that fine. So we should try my patch. 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/