From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vivek Goyal Subject: Re: [PATCH 17/24] blkcg: implement blkcg_policy->on/offline_pd_fn() and blkcg_gq->online Date: Wed, 2 Jan 2013 14:38:28 -0500 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 Return-path: Content-Disposition: inline In-Reply-To: <1356726946-26037-18-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tejun Heo Cc: lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, ctalbott-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, rni-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.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