From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750771AbWG2Xiv (ORCPT ); Sat, 29 Jul 2006 19:38:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750785AbWG2Xiu (ORCPT ); Sat, 29 Jul 2006 19:38:50 -0400 Received: from nz-out-0102.google.com ([64.233.162.200]:49121 "EHLO nz-out-0102.google.com") by vger.kernel.org with ESMTP id S1750771AbWG2Xiu (ORCPT ); Sat, 29 Jul 2006 19:38:50 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=nw5avyLYrKGMrsuF96RF7NoPXED3h/Kltoq8hdvkLMCAhfa3mf5a+M7c1BQRklR4T8WwTZUP29fecVf4JMA5NORXNSfAsRuSdLAGSebdKAc+zu0CVBuf+/yhAYYnh9gBzaNPfSNcYvUfE1rsbvt/BtdkO3dZ38EdIMydQNusVDg= Message-ID: <6bffcb0e0607291638p49d4190cx6d6a39ae84ecff99@mail.gmail.com> Date: Sun, 30 Jul 2006 01:38:49 +0200 From: "Michal Piotrowski" To: "Shailabh Nagar" Subject: Re: 2.6.18-rc2-mm1 Cc: "Matt Helsley" , "Andrew Morton" , LKML , "Balbir Singh" In-Reply-To: <44CBE26D.5090901@watson.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20060727015639.9c89db57.akpm@osdl.org> <6bffcb0e0607270632i2ae56e21k40fb12c712980de0@mail.gmail.com> <6bffcb0e0607280117k68184559t531b737815b2c6e9@mail.gmail.com> <20060728013442.6fabae54.akpm@osdl.org> <1154112567.21787.2522.camel@stark> <6bffcb0e0607281253j28e04ba2icec85589e9390b3e@mail.gmail.com> <1154119190.21787.2528.camel@stark> <44CBE26D.5090901@watson.ibm.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 30/07/06, Shailabh Nagar wrote: > Matt Helsley wrote: > > On Fri, 2006-07-28 at 21:53 +0200, Michal Piotrowski wrote: > > > >>On 28/07/06, Matt Helsley wrote: > >> > >>>On Fri, 2006-07-28 at 01:34 -0700, Andrew Morton wrote: > >>> > >>>>On Fri, 28 Jul 2006 10:17:44 +0200 > >>>>"Michal Piotrowski" wrote: > >>>> > >>>> > >>>>>Matt, can you look at this? > >>>>> > >>>>>My hunt file shows me, that this patches are causing oops. > >>>>>GOOD > >>>>># > >>>>># > >>>>>task-watchers-task-watchers.patch > >>>>>task-watchers-register-process-events-task-watcher.patch > >>>>>task-watchers-refactor-process-events.patch > >>>>>task-watchers-make-process-events-configurable-as.patch > >>>>>task-watchers-allow-task-watchers-to-block.patch > >>>>>task-watchers-register-audit-task-watcher.patch > >>>>>task-watchers-register-per-task-delay-accounting.patch > >>>>>task-watchers-register-profile-as-a-task-watcher.patch > >>>>>task-watchers-add-support-for-per-task-watchers.patch > >>>>>task-watchers-register-semundo-task-watcher.patch > >>>>>task-watchers-register-per-task-semundo-watcher.patch > >>>>>BAD > >>>> > >>>>Thanks for working that out. > >>> > >>> I noticed the delay accounting functions in the stack trace. Perhaps > >>>task-watchers-register-per-task-delay-accounting.patch is causing the > >>>problem. > >> > >>Confirmed. > > > > > > Excellent, thanks for the rapid confirmation. I'll work with Shailabh > > and Balbir to fix this. In the meantime perhaps > > task-watchers-register-per-task-delay-accounting.patch should be dropped > > from -mm. > > > > Cheers, > > -Matt Helsley > > > > > The error is almost certainly because delayacct_tsk_init is being > called at WATCH_TASK_CLONE (which is triggered after the task has been > added to the tasklist) rather than WATCH_INIT (before). > > __delayacct_tsk_init, which gets notified by WATCH_TASK_* initializes > the spinlock tsk->delays_lock which could get used as soon as task is > present in tasklist. The lockup is very likely due to use of this > uninitialized spinlock. > > So the fix should be to change WATCH_TASK_CLONE to WATCH_TASK_INIT > in the delayacct_watch_task function created by this patch. Problem solved. Thanks. > > --Shailabh > Regards, Michal -- Michal K. K. Piotrowski LTG - Linux Testers Group (http://www.stardust.webpages.pl/ltg/wiki/)