From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758474AbZBEQSt (ORCPT ); Thu, 5 Feb 2009 11:18:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754324AbZBEQSk (ORCPT ); Thu, 5 Feb 2009 11:18:40 -0500 Received: from mx2.redhat.com ([66.187.237.31]:56124 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754203AbZBEQSj (ORCPT ); Thu, 5 Feb 2009 11:18:39 -0500 Date: Thu, 5 Feb 2009 17:15:44 +0100 From: Oleg Nesterov To: Kaz Kylheku Cc: Roland McGrath , linux-kernel@vger.kernel.org, Andrew Morton , Ulrich Drepper Subject: Re: main thread pthread_exit/sys_exit bug! Message-ID: <20090205161544.GA24799@redhat.com> References: <3f43f78b0902011432y354c1b35m8f645640433f7b49@mail.gmail.com> <20090201174159.4a52e15c.akpm@linux-foundation.org> <20090202064509.GA20237@redhat.com> <3f43f78b0902012310p46186417m66873f410b948fd3@mail.gmail.com> <20090202165606.GA13346@redhat.com> <20090205030553.49650FC381@magilla.sf.frob.com> <3f43f78b0902042055p37ff9ab2u84840273b34c7373@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3f43f78b0902042055p37ff9ab2u84840273b34c7373@mail.gmail.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/04, Kaz Kylheku wrote: > > On Wed, Feb 4, 2009 at 7:05 PM, Roland McGrath wrote: > > I haven't seen the clear explanation of what specific actual problems there > > are here. But I'm quite sure this is not the right approach to address them. > > > > Kaz has said things that seemed to imply that the behavior is erratic or > > the semantics are somehow ill-defined when the group leader has died with > > other threads living on. In fact, this case is perfectly well-specified > > and there is no mystery about it. > > I haven't observed anything that could be called erratic. The behavior that > occurs, occurs reliably. Yes we have the bug, and wait_task_stopped() should be fixed. But it is buggy anyway, even if we delay the death of the main thread. But I also think we shouldn't. (and I am sorry, I still can't find the time to redo my old patch, will try to do this asap). Oleg.