Messages in this thread |  | | Date | Wed, 2 Jan 2013 15:37:18 -0500 | From | Tejun Heo <> | Subject | Re: [PATCH 17/24] blkcg: implement blkcg_policy->on/offline_pd_fn() and blkcg_gq->online |
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On Wed, Jan 02, 2013 at 02:38:28PM -0500, Vivek Goyal wrote: > 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.
Needs both locks to modify, so either lock is enough for checking.
-- tejun
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