Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932341AbWABJu4 (ORCPT ); Mon, 2 Jan 2006 04:50:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932342AbWABJu4 (ORCPT ); Mon, 2 Jan 2006 04:50:56 -0500 Received: from 213-140-2-68.ip.fastwebnet.it ([213.140.2.68]:58262 "EHLO aa001msg.fastwebnet.it") by vger.kernel.org with ESMTP id S932341AbWABJu4 (ORCPT ); Mon, 2 Jan 2006 04:50:56 -0500 Date: Mon, 2 Jan 2006 10:50:56 +0100 From: Paolo Ornati To: Mike Galbraith Cc: Linux Kernel Mailing List , Con Kolivas , Ingo Molnar , Nick Piggin , Peter Williams Subject: Re: [SCHED] wrong priority calc - SIMPLE test case Message-ID: <20060102105056.5e6d5205@localhost> In-Reply-To: <5.2.1.1.2.20060102092903.00bde090@pop.gmx.net> References: <5.2.1.1.2.20051231162352.00bda610@pop.gmx.net> <5.2.1.1.2.20051231090255.00bede00@pop.gmx.net> <200512281027.00252.kernel@kolivas.org> <20051227190918.65c2abac@localhost> <20051227224846.6edcff88@localhost> <200512281027.00252.kernel@kolivas.org> <5.2.1.1.2.20051231090255.00bede00@pop.gmx.net> <5.2.1.1.2.20051231162352.00bda610@pop.gmx.net> <5.2.1.1.2.20060102092903.00bde090@pop.gmx.net> X-Mailer: Sylpheed-Claws 2.0.0-rc1 (GTK+ 2.6.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1365 Lines: 32 On Mon, 02 Jan 2006 10:15:43 +0100 Mike Galbraith wrote: > >This is the bad situation I hate: some cpu-eaters that eat all the CPU > >time BUT have a really good priority only because they sleeps a bit. > > Yup, your proggy fools the interactivity estimator quite well. This > problem was addressed a long time ago, and thought to be more or less > cured. Guess not. In my original real-life test case (transcode) I found that the problem started with the removing of "interactive_credit": http://groups.google.com/group/fa.linux.kernel/browse_thread/thread/6aa5c93c379ae9e1/a9a83db6446edaf7?lnk=st&q=insubject%3Asched+author%3APaolo+author%3AOrnati&rnum=1&hl=en#a9a83db6446edaf7 This is not actually true... in fact that change only unhidden the problem for that particular test-case. With my little proggy I'm now able to reproduce the problem even with "interactive_credit" applied (for example with a 2.6.10 kernel). Said this, and since "nicksched" doesn't have this problem at all, it is an ingosched (and others as well) problem. -- Paolo Ornati Linux 2.6.15-rc7-plugsched on x86_64 - 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/