From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751206Ab1IEEEY (ORCPT ); Mon, 5 Sep 2011 00:04:24 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:38573 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750706Ab1IEEEU (ORCPT ); Mon, 5 Sep 2011 00:04:20 -0400 From: "Rafael J. Wysocki" To: Tejun Heo Subject: Re: [PATCHSET cgroup] extend threadgroup locking Date: Mon, 5 Sep 2011 06:05:57 +0200 User-Agent: KMail/1.13.6 (Linux/3.1.0-rc4+; KDE/4.6.0; x86_64; ; ) Cc: paul@paulmenage.org, lizf@cn.fujitsu.com, linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, fweisbec@gmail.com, matthltc@us.ibm.com, akpm@linux-foundation.org References: <1315159280-25032-1-git-send-email-htejun@gmail.com> In-Reply-To: <1315159280-25032-1-git-send-email-htejun@gmail.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-2" Content-Transfer-Encoding: 7bit Message-Id: <201109050605.57360.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Sunday, September 04, 2011, Tejun Heo wrote: > Hello, > > cgroup currently only blocks new threads from joining the target > threadgroup during migration, and on-going migration could race > against exec and exit leading to interesting problems - the symmetry > between various attach methods, task exiting during method execution, > ->exit() racing against attach methods, migrating task switching basic > properties during exec and so on. > > This patchset extends threadgroup locking such that it covers all > operations which can alter the threadgroup - fork, exit and exec, and > update cgroup to take advantage of it. rwsem read ops are added to > exit path but exec is excluded by grabbing the existing > cred_guard_mutex from threadgroup locking helper. > > This makes threadgroup locking complete and resolves cgroup issues > stemming from the target taskset being unstable. > > This patchset is on top of the current pm-freezer + "freezer: fixes & > simplifications" patchset and contains the following four patches. > Patch list and diffstat follow. OK I'm assuming that there will be a branch for me to pull from when kernel.org starts to work again, right? Rafael