Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261869AbTEYL0b (ORCPT ); Sun, 25 May 2003 07:26:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261932AbTEYL0b (ORCPT ); Sun, 25 May 2003 07:26:31 -0400 Received: from modemcable204.207-203-24.mtl.mc.videotron.ca ([24.203.207.204]:57729 "EHLO montezuma.mastecende.com") by vger.kernel.org with ESMTP id S261869AbTEYL03 (ORCPT ); Sun, 25 May 2003 07:26:29 -0400 Date: Sun, 25 May 2003 07:29:25 -0400 (EDT) From: Zwane Mwaikambo X-X-Sender: zwane@montezuma.mastecende.com To: Manfred Spraul cc: =?ISO-8859-1?Q?Mika_Penttil=E4?= , Ingo Molnar , Linux Kernel , William Lee Irwin III Subject: Re: [RFC][PATCH][2.5] Possible race in wait_task_zombie and finish_task_switch In-Reply-To: <3ED0A7CF.9040803@colorfullife.com> Message-ID: References: <3ED0A248.10308@kolumbus.fi> <3ED0A7CF.9040803@colorfullife.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1268 Lines: 36 On Sun, 25 May 2003, Manfred Spraul wrote: > - the reference for the stack itself, acquired by setting usage to 2, > dropped by schedule_tail. > - the reference for wait4, acquired by setting usage to 2, dropped by > wait_task_zombie. > - references for the pid structures, maintained by pid.c > - temporary references for looking at tsk->{fs,mm,files,tty}, used by > /proc, ptrace, tty. it's the one dropped by wait_task_zombie, the task coming out from schedule_tail is fine. > > >kernel BUG at kernel/sched.c:746! > > > > > Hmm. What is schedule.c:746? There is no BUG in that area in the bk tree. It's in finish_arch_switch at the put_task_struct() > Zwane, is it easy to reproduce the crash? I could write a patch that > adds 4 refcounters, then we could find out in which area we must look. I haven't found a direct way of triggering it, so far it's just been cropping up ~6 times over a period of 2days with the box normally taking a fatal one and dying completely. Zwane -- function.linuxpower.ca - 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/