From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759358AbXGZIQn (ORCPT ); Thu, 26 Jul 2007 04:16:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753442AbXGZIQY (ORCPT ); Thu, 26 Jul 2007 04:16:24 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:60337 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752574AbXGZIQW (ORCPT ); Thu, 26 Jul 2007 04:16:22 -0400 Date: Thu, 26 Jul 2007 10:16:09 +0200 From: Ingo Molnar To: Marcin =?utf-8?Q?=C5=9Alusarz?= Cc: Thomas Gleixner , Linus Torvalds , Jarek Poplawski , Jean-Baptiste Vignaud , linux-kernel , shemminger , linux-net , netdev , Andrew Morton Subject: Re: 2.6.20->2.6.21 - networking dies after random time Message-ID: <20070726081609.GA24377@elte.hu> References: <20070629150759.GC2771@ff.dom.local> <4bacf17f0707222244p664e7a6ap850b3357a57d73c@mail.gmail.com> <20070724080534.GC18740@elte.hu> <20070724094202.GA11610@elte.hu> <20070724200431.GA22190@elte.hu> <1185322771.4175.102.camel@chaos> <4bacf17f0707260016x14fc1c92s628ae64353663833@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4bacf17f0707260016x14fc1c92s628ae64353663833@mail.gmail.com> User-Agent: Mutt/1.5.14 (2007-02-12) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.1.7-deb -1.0 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 * Marcin Ślusarz wrote: > 2007/7/25, Thomas Gleixner : > >(...) > > I've tested Jarek's patch, 2 Ingo's patches (2nd and 3rd) and Thomas' > patch (one patch at time of course) - all of them fixed the problem, > but the last one flooded my logs with "Skip resend for irq 17". All > tests were done on 2.6.21.3. that's great! I think we have two good theories about what might be going on: - the driver might be buggy in that it gets confused by the 'resent' irq. - or the chipset/cpu has a bug where it might get confused about the resent APIC vector getting mixed up with the same vector coming externally too. (Now, it makes little sense to 'resend' a level-triggered interrupt on x86 platforms that have flat PIC hierarchies (other architectures might need more than that to retrigger an interrupt) - but there's nothing wrong about it in theory and it needs fixing for edge irqs anyway.) in any case, the problem was triggered by our change generating much more resent irqs than before. Nevertheless we'd like to fix that resend bug (and if the driver is buggy, the driver bug too). It's really good progress so far - we are working on doing the real fix now. Ingo