From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935345AbXGRRYX (ORCPT ); Wed, 18 Jul 2007 13:24:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752918AbXGRRYP (ORCPT ); Wed, 18 Jul 2007 13:24:15 -0400 Received: from smtp2.linux-foundation.org ([207.189.120.14]:42461 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752682AbXGRRYO (ORCPT ); Wed, 18 Jul 2007 13:24:14 -0400 Date: Wed, 18 Jul 2007 10:23:17 -0700 (PDT) From: Linus Torvalds To: Ingo Molnar cc: Ian Kent , davids@webmaster.com, "Linux-Kernel@Vger. Kernel. Org" , Chuck Ebbert , Bill Davidsen , Thomas Gleixner Subject: Re: [patch] CFS scheduler, -v19 In-Reply-To: <20070718075417.GA7895@elte.hu> Message-ID: References: <1184738344.4178.18.camel@raven.themaw.net> <20070718075417.GA7895@elte.hu> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 18 Jul 2007, Ingo Molnar wrote: > > Linus, Thomas, what do you think, should we keep the time.c change? No, not if it's off by the second field. That 30% CPU usage indicates that there's some nasty bug there somewhere, and that's just not worth it. If time() cannot get the second field right, it's bogus. I'm ok with us not *guaranteeing* monotonicity of the second field when you compare gettimeofday() with time(), but the 30% thing implies that it's much worse than that, and that "time()" will likely report the previous second (when compared to hrtimers) roughly a quarter of the time. And that isn't acceptable. So either it should be fixed, or reverted. Linus