From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751789AbXLDSln (ORCPT ); Tue, 4 Dec 2007 13:41:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750885AbXLDSlf (ORCPT ); Tue, 4 Dec 2007 13:41:35 -0500 Received: from perninha.conectiva.com.br ([200.140.247.100]:37908 "EHLO perninha.conectiva.com.br" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750813AbXLDSle (ORCPT ); Tue, 4 Dec 2007 13:41:34 -0500 Date: Tue, 4 Dec 2007 16:41:24 -0200 From: "Luiz Fernando N. Capitulino" To: Greg KH Cc: Ingo Molnar , Linus Torvalds , Linux Kernel Mailing List , herton@mandriva.com.br, dvgevers@xs4all.nl Subject: Re: [git pull] scheduler fixes Message-ID: <20071204164124.447a5c36@mandriva.com.br> In-Reply-To: <20071204182851.GA18208@kroah.com> References: <20071204120715.4ea204a8@mandriva.com.br> <20071204160005.GA29783@elte.hu> <20071204161827.GA491@elte.hu> <20071204182851.GA18208@kroah.com> Organization: Mandriva X-Mailer: Claws Mail 3.1.0 (GTK+ 2.12.2; i586-mandriva-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Tue, 4 Dec 2007 10:28:51 -0800 Greg KH escreveu: | On Tue, Dec 04, 2007 at 05:18:27PM +0100, Ingo Molnar wrote: | > | > * Ingo Molnar wrote: | > | > > The problem is on SMP: if sched_rr_get_interval() gets a task from an | > > otherwise idle runqueue, then rq->load.weight is 0. Normally | > > sched_slice() is only used on a busy runqueue. So the correct fixup | > > site is not in sched_slice() but in sys_sched_rr_get_interval() - i'm | > > working on the right fix, i hope to be able to send a pull request in | > > a few minutes. | > | > the problem is on UP too - if there are no SCHED_OTHER tasks. I've | > tested the fix and it solves the problem for various combinations of | > crash.c. I've updated sched.git, please pull it from: | > | > git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched.git | > | > It has another commit besides this fix. Thanks, | | Can you make up something that I can apply for 2.6.23-stable? or is | this not an issue on that tree? FWIW I couldn't reproduce the problem with 2.6.23.9. sched_slice() is quite different on that kernel and _maybe_ it won't never divide by zero. My original report on vendor-sec was wrong. I've said that 2.6.23.9 had the same bug but turns out the kernel I tested had the Ingo's CFS backport patch applied. I didn't know that, I thought it was a vanilla kernel. Btw, I think it's important to release a new CFS backport patch because maybe some distro is using it (Mandriva stable kernel is using the CFS backport patch, but we didn't update to latest version yet). -- Luiz Fernando N. Capitulino