From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267594AbUH2CVS (ORCPT ); Sat, 28 Aug 2004 22:21:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267596AbUH2CVS (ORCPT ); Sat, 28 Aug 2004 22:21:18 -0400 Received: from mustang.oldcity.dca.net ([216.158.38.3]:60373 "HELO mustang.oldcity.dca.net") by vger.kernel.org with SMTP id S267594AbUH2CUp (ORCPT ); Sat, 28 Aug 2004 22:20:45 -0400 Subject: Re: Scheduler fairness problem on 2.6 series (Attn: Nick Piggin and others) From: Lee Revell To: spaminos-ker@yahoo.com Cc: Peter Williams , linux-kernel In-Reply-To: <20040829011936.39122.qmail@web13907.mail.yahoo.com> References: <20040829011936.39122.qmail@web13907.mail.yahoo.com> Content-Type: text/plain Message-Id: <1093746044.7078.29.camel@krustophenia.net> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Sat, 28 Aug 2004 22:20:45 -0400 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 2004-08-28 at 21:19, spaminos-ker@yahoo.com wrote: > --- Lee Revell wrote: > > Is this an SMP machine? There were problems with that version of the > > voluntary preemption patches on SMP. The latest version, Q3, should fix > > these. > > > No, it's a single CPU Athlon 1800+, the kernel is compiled in with support for > SMP system, but that should not have any impact. > It shouldn't, but it can. For example taking a spinlock just disables preemption with a UP kernel, but with an SMP kernel I believe you can actually end up spinning. You would have to have hit a locking bug or race condition for this to happen. Just to be certain, can you reproduce the problem with a UP kernel? Lee