From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965069AbXCQH41 (ORCPT ); Sat, 17 Mar 2007 03:56:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965105AbXCQH41 (ORCPT ); Sat, 17 Mar 2007 03:56:27 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:47386 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965069AbXCQH40 (ORCPT ); Sat, 17 Mar 2007 03:56:26 -0400 Date: Sat, 17 Mar 2007 08:56:15 +0100 From: Ingo Molnar To: Nicholas Miell Cc: Mike Galbraith , Con Kolivas , ck@vds.kolivas.org, Al Boldi , Andrew Morton , Linus Torvalds , linux-kernel@vger.kernel.org Subject: Re: RSDL v0.31 Message-ID: <20070317075615.GC13685@elte.hu> References: <200703042335.26785.a1426z@gawab.com> <200703170040.48316.kernel@kolivas.org> <1174059299.7886.25.camel@Homer.simpson.net> <200703170813.32594.kernel@kolivas.org> <1174084207.7009.9.camel@Homer.simpson.net> <1174105443.3144.4.camel@entropy> <1174110965.7911.44.camel@Homer.simpson.net> <1174112768.3144.8.camel@entropy> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1174112768.3144.8.camel@entropy> User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.1.7 -2.0 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 * Nicholas Miell wrote: > > I'm saying that the current scheduler adjusts for interactive loads, > > this new one doesn't. I'm seeing interactivity regressions, and > > they are not fixed with nice unless nice is used to maximum effect. > > I'm saying yes, I can lower my expectations, but no I don't want to. > > Uh, no. Essentially, the current scheduler works around X's > brokenness, in an often unpredictable manner. No. The two schedulers simply use different heuristics. RSDL uses _less_ heuristics, and thus gets some workloads right that the heuristics in the current scheduler got wrong. But it also gets some other workloads wrong. so basically, the current scheduler has a built-in "auto-nice" feature, while RSDL relies more on manual assignment of nice values. if you want no heuristics at all you can do it in the current scheduler: use SCHED_BATCH on your shell and start up X with that. I'd not mind tweaking SCHED_BATCH with an RSDL-alike timeslice quota system. so it is not at all clear to me that RSDL is indeed an improvement, if it does not have comparable auto-nice properties. Ingo