Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932853AbWLZXnG (ORCPT ); Tue, 26 Dec 2006 18:43:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932860AbWLZXnF (ORCPT ); Tue, 26 Dec 2006 18:43:05 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:48288 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932853AbWLZXnE (ORCPT ); Tue, 26 Dec 2006 18:43:04 -0500 Date: Wed, 27 Dec 2006 00:40:45 +0100 From: Ingo Molnar To: Steven Rostedt Cc: Robert Crocombe , linux-kernel Subject: Re: 2.6.19.1-rt15: BUG in __tasklet_action at kernel/softirq.c:568 Message-ID: <20061226234045.GC6003@elte.hu> References: <20061219175728.GA20262@elte.hu> <20061220195008.GB14316@elte.hu> <1166671151.852.4.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1166671151.852.4.camel@localhost.localdomain> User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -5.9 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-5.9 required=5.9 tests=ALL_TRUSTED,BAYES_00 autolearn=no SpamAssassin version=3.0.3 -3.3 ALL_TRUSTED Did not pass through any untrusted hosts -2.6 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 Content-Length: 1252 Lines: 33 * Steven Rostedt wrote: > On Wed, 2006-12-20 at 20:50 +0100, Ingo Molnar wrote: > > * Robert Crocombe wrote: > > > > > On 12/19/06, Ingo Molnar wrote: > > > >yeah. This is something that triggers very rarely on certain boxes. Not > > > >fixed yet, and it's been around for some time. > > > > > > Is there anything you would like me to do to help diagnose this? > > > > to figure out what the bug is :-/ Below is the tasklet redesign patch - > > the bug must be in there somewhere. > > > +static inline int tasklet_tryunlock(struct tasklet_struct *t) > > +{ > > + return cmpxchg(&t->state, TASKLET_STATEF_RUN, 0) == TASKLET_STATEF_RUN; > > +} > > + > > This probably isn't it, but is cmpxchg available on all archs now? yeah, it's probably not related, i saw these failures on plain i686 too, which definitely has cmpxchg support. The failures i saw happened on a hyperthreading CPU, so i guess it must be some sort of narrow race. Ingo - 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/