From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757451AbYAVVH0 (ORCPT ); Tue, 22 Jan 2008 16:07:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753940AbYAVVHL (ORCPT ); Tue, 22 Jan 2008 16:07:11 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:52561 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752642AbYAVVHJ (ORCPT ); Tue, 22 Jan 2008 16:07:09 -0500 Date: Tue, 22 Jan 2008 22:06:59 +0100 From: Ingo Molnar To: Arjan van de Ven Cc: linux-kernel@vger.kernel.org Subject: Re: [patch] sched: Keep total / count stats in addition to the max for wait time Message-ID: <20080122210659.GA26764@elte.hu> References: <20080121110809.1b584998@laptopd505.fenrus.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080121110809.1b584998@laptopd505.fenrus.org> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0008] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Arjan van de Ven wrote: > From: Arjan van de Ven > Subject: sched: Keep total / count stats in addition to the max for wait time > > Right now, the linux kernel (with scheduler statistics enabled) keeps > track of the maximum time a process is waiting to be scheduled. While > the maximum is a very useful metric, tracking average and total is > equally useful (at least for latencytop) to figure out the accumulated > effect of scheduler delays. The accumulated effect is important to > judge the performance impact of scheduler tuning/behavior. thanks, applied to sched-devel.git. Ingo