From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756182Ab2CLSEc (ORCPT ); Mon, 12 Mar 2012 14:04:32 -0400 Received: from mail-gx0-f174.google.com ([209.85.161.174]:48893 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756027Ab2CLSE3 (ORCPT ); Mon, 12 Mar 2012 14:04:29 -0400 Date: Mon, 12 Mar 2012 11:04:23 -0700 From: Tejun Heo To: Sasha Levin Cc: axboe@kernel.dk, linux-kernel@vger.kernel.org, Vivek Goyal Subject: Re: [PATCH] blk-cgroup: Call cgroup_path only under cgroup lock Message-ID: <20120312180423.GC23255@google.com> References: <1331582478-2259-1-git-send-email-levinsasha928@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1331582478-2259-1-git-send-email-levinsasha928@gmail.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Sasha. On Mon, Mar 12, 2012 at 04:01:18PM -0400, Sasha Levin wrote: > Since we can't keep rcu read lock during blkg_alloc(), we currently > call cgroup_path() without any locks at all. > > This patch adds cgroup locking before calling cgroup_path. > > This also fixes a lockdep warning on boot. > > Signed-off-by: Sasha Levin Which branch is this against? There's already pending stat update patch from Vivek which fix this problem along with the percpu allocation problem. Thanks. -- tejun