From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755441AbZBDJQv (ORCPT ); Wed, 4 Feb 2009 04:16:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752287AbZBDJQI (ORCPT ); Wed, 4 Feb 2009 04:16:08 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:63022 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754862AbZBDJQG (ORCPT ); Wed, 4 Feb 2009 04:16:06 -0500 Message-ID: <49895CAD.1020008@cn.fujitsu.com> Date: Wed, 04 Feb 2009 17:15:25 +0800 From: Li Zefan User-Agent: Thunderbird 2.0.0.9 (X11/20071115) MIME-Version: 1.0 To: Andrew Morton CC: Paul Menage , LKML , Linux Containers Subject: Re: [PATCH] cgroups: fix lockdep subclasses overflow References: <49895BD7.8090405@cn.fujitsu.com> In-Reply-To: <49895BD7.8090405@cn.fujitsu.com> 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 Li Zefan wrote: > I enabled all cgroup subsystems when compiling kernel, and then: > # mount -t cgroup -o net_cls xxx /mnt > # mkdir /mnt/0 > > This showed up immediately: > BUG: MAX_LOCKDEP_SUBCLASSES too low! > turning off the locking correctness validator. > > It's caused by the cgroup hierarchy lock: > for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { > struct cgroup_subsys *ss = subsys[i]; > if (ss->root == root) > mutex_lock_nested(&ss->hierarchy_mutex, i); > } > > Now we have 9 cgroup subsystems, and the above 'i' for net_cls is 9, but sorry, a typo here: the above 'i' for net_cls is 8. > MAX_LOCKDEP_SUBCLASSES is 8. > > This patch uses different lockdep keys for different subsystems. > > Signed-off-by: Li Zefan > ---