From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: + cgroup-check-task_lock-in-task_subsys_state.patch added to -mm tree Date: Mon, 26 Apr 2010 12:15:30 -0700 Message-ID: <201004261915.o3QJFUBP014170@imap1.linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:54334 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752589Ab0DZTQK (ORCPT ); Mon, 26 Apr 2010 15:16:10 -0400 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: mm-commits@vger.kernel.org Cc: lizf@cn.fujitsu.com, matthltc@us.ibm.com, menage@google.com, paulmck@linux.vnet.ibm.com The patch titled cgroup: check task_lock in task_subsys_state() has been added to the -mm tree. Its filename is cgroup-check-task_lock-in-task_subsys_state.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: cgroup: check task_lock in task_subsys_state() From: Li Zefan task_subsys_state() is safe under task_lock(). See Documentation/cgroups/cgroups.txt for locking rule. This fixes an RCU warning when resume from suspend. The warning comes from freezer cgroup in cgroup_freezing_or_frozen(). Signed-off-by: Li Zefan Acked-by: Matt Helsley Cc: "Paul E. McKenney" Cc: Paul Menage Signed-off-by: Andrew Morton --- include/linux/cgroup.h | 1 + 1 file changed, 1 insertion(+) diff -puN include/linux/cgroup.h~cgroup-check-task_lock-in-task_subsys_state include/linux/cgroup.h --- a/include/linux/cgroup.h~cgroup-check-task_lock-in-task_subsys_state +++ a/include/linux/cgroup.h @@ -530,6 +530,7 @@ static inline struct cgroup_subsys_state { return rcu_dereference_check(task->cgroups->subsys[subsys_id], rcu_read_lock_held() || + lockdep_is_held(&task->alloc_lock) || cgroup_lock_is_held()); } _ Patches currently in -mm which might be from lizf@cn.fujitsu.com are origin.patch linux-next.patch cgroup-check-task_lock-in-task_subsys_state.patch memcg-rcu-lock-fix-v3.patch