From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752788Ab3ABTih (ORCPT ); Wed, 2 Jan 2013 14:38:37 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42537 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752426Ab3ABTif (ORCPT ); Wed, 2 Jan 2013 14:38:35 -0500 Date: Wed, 2 Jan 2013 14:38:28 -0500 From: Vivek Goyal To: Tejun Heo Cc: lizefan@huawei.com, axboe@kernel.dk, containers@lists.linux-foundation.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, ctalbott@google.com, rni@google.com Subject: Re: [PATCH 17/24] blkcg: implement blkcg_policy->on/offline_pd_fn() and blkcg_gq->online Message-ID: <20130102193828.GE4306@redhat.com> References: <1356726946-26037-1-git-send-email-tj@kernel.org> <1356726946-26037-18-git-send-email-tj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1356726946-26037-18-git-send-email-tj@kernel.org> 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 Fri, Dec 28, 2012 at 12:35:39PM -0800, Tejun Heo wrote: [..] > diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h > index 40f5b97..678e89e 100644 > --- a/block/blk-cgroup.h > +++ b/block/blk-cgroup.h > @@ -106,12 +106,17 @@ struct blkcg_gq { > /* reference count */ > int refcnt; > > + /* is this blkg online? protected by both blkcg and q locks */ > + bool online; > + Hi Tejun, What does above mean? One needs to take one lock or both the locks to check/modify blkg->online. Thanks Vivek