From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756499Ab1G2NCr (ORCPT ); Fri, 29 Jul 2011 09:02:47 -0400 Received: from mga11.intel.com ([192.55.52.93]:36933 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755379Ab1G2NCp (ORCPT ); Fri, 29 Jul 2011 09:02:45 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,287,1309762800"; d="scan'208";a="33748046" Subject: Re: [PATCH 4/8] coredump_wait: don't call complete_vfork_done() From: Matt Fleming To: Oleg Nesterov Cc: Linus Torvalds , Roland McGrath , Tejun Heo , Denys Vlasenko , KOSAKI Motohiro , linux-kernel@vger.kernel.org In-Reply-To: <20110727163311.GD23793@redhat.com> References: <20110727163159.GA23785@redhat.com> <20110727163311.GD23793@redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Fri, 29 Jul 2011 14:02:35 +0100 Message-ID: <1311944555.21232.68.camel@mfleming-mobl1.ger.corp.intel.com> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 (2.32.2-1.fc14) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2011-07-27 at 18:33 +0200, Oleg Nesterov wrote: > Now that CLONE_VFORK is killable, coredump_wait() no longer needs > complete_vfork_done(). zap_threads() should find and kill all tasks > with the same ->mm, this includes our parent if ->vfork_done is set. > > mm_release() becomes the only caller, unexport complete_vfork_done(). > > Signed-off-by: Oleg Nesterov Isn't there a subtle change in user-visible behaviour regarding wait() with this patch? Before the patch, if a child dumps its core it will wakeup the parent which can read the status of the child via wait(), whereas with this patch applied the parent will actually be killed along with the child. I'm not trying to say which behaviour I think is the correct one, just that because it is a user-visible change and it is maybe worth a bit more discussion in the changelog?