From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763724AbXHARs4 (ORCPT ); Wed, 1 Aug 2007 13:48:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757405AbXHARss (ORCPT ); Wed, 1 Aug 2007 13:48:48 -0400 Received: from one.firstfloor.org ([213.235.205.2]:34187 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752197AbXHARsr (ORCPT ); Wed, 1 Aug 2007 13:48:47 -0400 Date: Wed, 1 Aug 2007 19:48:44 +0200 From: Andi Kleen To: Linus Torvalds Cc: Andi Kleen , Ingo Molnar , Roman Zippel , Mike Galbraith , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: CFS review Message-ID: <20070801174844.GA20713@one.firstfloor.org> 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/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > 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*. It might just have been cpufreq. That nearly hits everybody with cpufreq unless you have a pstate invariant TSC; and that's pretty much always the case on older laptops. It used to not be that drastic, but since i386 switched to the generic clock frame work it is like that :/ > These days, of course, we should notice it on our own, and just switch > away from the TSC as a reliable clock-source, but still allow it to be > used for the cases where absolute accuracy is not a big issue. The rewritten sched_clock() i still have queued does just that. I planned to submit it for .23, but then during later in deepth testing on my machine park I found a show stopper that I couldn't fix on time. Hopefully for .24 -Andi