From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762185Ab2DLIKA (ORCPT ); Thu, 12 Apr 2012 04:10:00 -0400 Received: from mail-lpp01m010-f46.google.com ([209.85.215.46]:44101 "EHLO mail-lpp01m010-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756515Ab2DLIJ4 (ORCPT ); Thu, 12 Apr 2012 04:09:56 -0400 Subject: [PATCH 2/2] mm: call complete_vfork_done() after clearing child_tid and flushing rss-counters To: Andrew Morton From: Konstantin Khlebnikov Cc: Hugh Dickins , Oleg Nesterov , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Markus Trippelsdorf , KAMEZAWA Hiroyuki Date: Thu, 12 Apr 2012 12:09:53 +0400 Message-ID: <20120412080952.26401.2025.stgit@zurg> In-Reply-To: <20120409200336.8368.63793.stgit@zurg> References: <20120409200336.8368.63793.stgit@zurg> User-Agent: StGit/0.15 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Child should wake ups parent from vfork() only after finishing all operations with shared mm. There is no sense to use CLONE_CHILD_CLEARTID together with CLONE_VFORK, but it looks more accurate now. Signed-off-by: Konstantin Khlebnikov Cc: Oleg Nesterov --- kernel/fork.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/kernel/fork.c b/kernel/fork.c index 326bb5b..f10ac1d 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -728,9 +728,6 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm) /* Get rid of any cached register state */ deactivate_mm(tsk, mm); - if (tsk->vfork_done) - complete_vfork_done(tsk); - /* * If we're exiting normally, clear a user-space tid field if * requested. We leave this alone when dying by signal, to leave @@ -759,6 +756,13 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm) */ if (mm) sync_mm_rss(mm); + + /* + * All done, finally we can wake up parent and return this mm to him. + * Also kthread_stop() uses this completion for synchronization. + */ + if (tsk->vfork_done) + complete_vfork_done(tsk); } /*