From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id 9479E6B0082 for ; Thu, 17 Sep 2009 17:12:11 -0400 (EDT) Date: Thu, 17 Sep 2009 23:08:06 +0200 From: Oleg Nesterov Subject: Re: cgrooups && 2.6.32 -mm merge plans Message-ID: <20090917210806.GA31441@redhat.com> References: <20090915161535.db0a6904.akpm@linux-foundation.org> <20090917201516.GA29346@redhat.com> <20090917133846.a00daece.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090917133846.a00daece.akpm@linux-foundation.org> Sender: owner-linux-mm@kvack.org To: Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, menage@google.com, bblum@google.com, ebiederm@xmission.com, lizf@cn.fujitsu.com, matthltc@us.ibm.com List-ID: On 09/17, Andrew Morton wrote: > > On Thu, 17 Sep 2009 22:15:16 +0200 > Oleg Nesterov wrote: > > > On 09/15, Andrew Morton wrote: > > > > > > #cgroups-add-functionality-to-read-write-lock-clone_thread-forking-per-threadgroup.patch: Oleg conniptions > > > cgroups-add-functionality-to-read-write-lock-clone_thread-forking-per-threadgroup.patch > > > cgroups-add-functionality-to-read-write-lock-clone_thread-forking-per-threadgroup-fix.patch > > > cgroups-add-ability-to-move-all-threads-in-a-process-to-a-new-cgroup-atomically.patch > > > > > > Merge after checking with Oleg. > > > > Well. I think these patches are buggy :/ > > > > Well that's never prevented us from merging stuff before. > > Thanks, I'll disable the patches for now. Do we have a grip on what's > wrong and what needs to be done to fix things? Afaics, ->threadgroup_fork_lock doesn't really work, we can race with exec. list_for_each_entry_rcu() loops in these patches are not safe. And in fact, personally I dislike even atomic_inc(&sighand->count). Just consider sys_unshare(CLONE_SIGHAND). Yes, this code is a joke, but still. Sadly, I don't have any ideas how to fix this... I'd wish I had a time to at least try to find the solution ;) Oleg. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org