Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761375AbXHEVJS (ORCPT ); Sun, 5 Aug 2007 17:09:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752394AbXHEVJE (ORCPT ); Sun, 5 Aug 2007 17:09:04 -0400 Received: from mail.screens.ru ([213.234.233.54]:58943 "EHLO mail.screens.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751888AbXHEVJD (ORCPT ); Sun, 5 Aug 2007 17:09:03 -0400 Date: Mon, 6 Aug 2007 01:09:21 +0400 From: Oleg Nesterov To: Roland McGrath Cc: Andrew Morton , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] wait_task_zombie: remove unneeded child->signal check Message-ID: <20070805210921.GA270@tv-sign.ru> References: <20070805150041.GA2016@tv-sign.ru> <20070805205144.314B04D04C4@magilla.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070805205144.314B04D04C4@magilla.localdomain> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 736 Lines: 20 On 08/05, Roland McGrath wrote: > > > A zombie must have a valid ->signal, we are going to release it and > > __exit_signal() starts with BUG_ON(!sig). > > Yes, this is safe because it's after the EXIT_DEAD check under tasklist_lock. Yes thanks, the changelog could be better. We "own" this child (it was us sho set EXIT_DEAD), nobody can release it including the child itself (it already passed exit_notify()). We could even drop tasklist, but we need ->parent->sighand->siglock. Oleg. - 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/