Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261847AbTEYLLX (ORCPT ); Sun, 25 May 2003 07:11:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261932AbTEYLLX (ORCPT ); Sun, 25 May 2003 07:11:23 -0400 Received: from dbl.q-ag.de ([80.146.160.66]:33171 "EHLO dbl.q-ag.de") by vger.kernel.org with ESMTP id S261847AbTEYLLQ (ORCPT ); Sun, 25 May 2003 07:11:16 -0400 Message-ID: <3ED0A7CF.9040803@colorfullife.com> Date: Sun, 25 May 2003 13:23:59 +0200 From: Manfred Spraul User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.3) Gecko/20030312 X-Accept-Language: en-us, en MIME-Version: 1.0 To: =?ISO-8859-1?Q?Mika_Penttil=E4?= CC: Zwane Mwaikambo , Ingo Molnar , Linux Kernel , William Lee Irwin III Subject: Re: [RFC][PATCH][2.5] Possible race in wait_task_zombie and finish_task_switch References: <3ED0A248.10308@kolumbus.fi> In-Reply-To: <3ED0A248.10308@kolumbus.fi> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 982 Lines: 27 Do we have an idea which reference is miscounted? It seems that there are 4 different kinds of references to a task structure: - 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. >kernel BUG at kernel/sched.c:746! > > Hmm. What is schedule.c:746? There is no BUG in that area in the bk tree. 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. -- Manfred - 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/