Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760002AbXHTTF3 (ORCPT ); Mon, 20 Aug 2007 15:05:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754721AbXHTTFU (ORCPT ); Mon, 20 Aug 2007 15:05:20 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:39974 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754129AbXHTTFS (ORCPT ); Mon, 20 Aug 2007 15:05:18 -0400 Date: Mon, 20 Aug 2007 21:05:09 +0200 From: Ingo Molnar To: Martin Schwidefsky Cc: Christian Borntraeger , Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, Jan Glauber , heiko.carstens@de.ibm.com, Paul Mackerras Subject: Re: [accounting regression since rc1] scheduler updates Message-ID: <20070820190509.GA3714@elte.hu> References: <20070812163225.GA11996@elte.hu> <200708141037.48001.borntraeger@de.ibm.com> <20070820154529.GA300@elte.hu> <1187629438.8541.40.camel@localhost> <20070820180810.GA25160@elte.hu> <1187634782.4028.10.camel@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1187634782.4028.10.camel@localhost> 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=3.0.3 -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 Content-Length: 1623 Lines: 32 * Martin Schwidefsky wrote: > On Mon, 2007-08-20 at 20:08 +0200, Ingo Molnar wrote: > > For sched_clock()'s behavior while the virtual CPU is idle: my current > > idea for that is the patch below (a loosely analoguous problem exists > > with nohz/dynticks): it makes sched_clock() valid across idle periods > > too and uses wall-clock time for that. > > Ok, that would mean that sched_clock can just return the virtual cpu > time and the two hooks starts and stops the idle periods as far as the > scheduler is concerned. In this case we can use the patch from Jan > with the new implementation for sched_clock and add the two hooks to > the places where the cpu-idle notifiers are done (do_monitor_call and > default_idle). In fact this could be an idle-notifier. Hmm, I take a > closer look tomorrow when I'm back at the office. ok. Just to make it sure wrt. release-management: you said s390 sched_clock() is currently at least as precise as stime/utime - so this would suggest that there is no regression over v2.6.22? Regardless of whether it's a live regression or not, i think we want the nohz improvement (and the s390 patch if the callbacks are OK to you) in .23, and we want to migrate all users of "raw" sched_clock() [blktrace, softlockup-detector, print-timestamps, etc.] over to the better cpu_clock() interface. 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/