From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755534AbaCCWde (ORCPT ); Mon, 3 Mar 2014 17:33:34 -0500 Received: from mail-qa0-f44.google.com ([209.85.216.44]:57600 "EHLO mail-qa0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755241AbaCCWdc (ORCPT ); Mon, 3 Mar 2014 17:33:32 -0500 Date: Mon, 3 Mar 2014 17:33:27 -0500 From: Tejun Heo To: Sasha Levin Cc: lizefan@huawei.com, containers@lists.linux-foundation.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] cgroup: missing rcu read lock around task_css_set Message-ID: <20140303223327.GB26523@mtj.dyndns.org> References: <1393729211-937-1-git-send-email-sasha.levin@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1393729211-937-1-git-send-email-sasha.levin@oracle.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Mar 01, 2014 at 10:00:11PM -0500, Sasha Levin wrote: > rcu read lock should be held when calling and working with task_css_set. > > This patch also fixes a related lockdep warning. Hmmm... PF_EXITING should be visible at that point and cset can't change anymore. We prolly need to update lockdep annotation rather than adding spurious rcu locking around it. Against which branch is it? Can you please post the lockdep warning? Thanks. -- tejun