From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756321AbYCCMxF (ORCPT ); Mon, 3 Mar 2008 07:53:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756169AbYCCMwr (ORCPT ); Mon, 3 Mar 2008 07:52:47 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:54249 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755016AbYCCMwq (ORCPT ); Mon, 3 Mar 2008 07:52:46 -0500 Date: Mon, 3 Mar 2008 13:52:27 +0100 From: Ingo Molnar To: Michael Kerrisk Cc: Arnd Bergmann , Christoph Hellwig , cbe-oss-dev@ozlabs.org, Jeremy Kerr , linux-kernel@vger.kernel.org Subject: Re: SCHED_IDLE documentation Message-ID: <20080303125227.GA22160@elte.hu> References: <1203376368.275756.252634247263.1.gpush@pokey> <200803030612.28039.arnd@arndb.de> <20080303051719.GA26102@lst.de> <200803030721.52869.arnd@arndb.de> <20080303073311.GB5934@elte.hu> <20080303092422.GA18281@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Michael Kerrisk wrote: > > > * What's the difference between SCHED_IDLE and SCHED_BATCH? > > > > SCHED_BATCH can still have nice levels from -20 to +19, it is a > > modified SCHED_OTHER/SCHED_NORMAL for "throughput oriented" > > workloads. > > So, suppose we have two CPU intensive jobs, one SCHED_OTHER and the > other SCHED_BATCH. If they have the same nice value, will/should the > scheduler favour one over the other? yes - SCHED_BATCH does not modify the CPU usage proportion for CPU-intense tasks, it's their nice value that controls the proportion. What it will influence is wakeup behavior - i.e. wakeup-intense workloads should schedule less with SCHED_BATCH. (but how that is done is really fluid and will probably tweaked in the future.) Ingo