Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161730Ab3DENjM (ORCPT ); Fri, 5 Apr 2013 09:39:12 -0400 Received: from cantor2.suse.de ([195.135.220.15]:59392 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161548Ab3DENjK (ORCPT ); Fri, 5 Apr 2013 09:39:10 -0400 Date: Fri, 5 Apr 2013 15:39:09 +0200 From: Michal Hocko To: Li Zefan Cc: linux-mm@kvack.org, LKML , Cgroups , Tejun Heo , Glauber Costa , KAMEZAWA Hiroyuki , Johannes Weiner Subject: Re: [RFC][PATCH 1/7] memcg: use css_get in sock_update_memcg() Message-ID: <20130405133909.GF31132@dhcp22.suse.cz> References: <515BF233.6070308@huawei.com> <515BF249.50607@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <515BF249.50607@huawei.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 Content-Length: 1769 Lines: 58 On Wed 03-04-13 17:11:37, Li Zefan wrote: > Use css_get/css_put instead of mem_cgroup_get/put. > > Note, if at the same time someone is moving @current to a different > cgroup and removing the old cgroup, css_tryget() may return false, > and sock->sk_cgrp won't be initialized. > > Signed-off-by: Li Zefan Acked-by: Michal Hocko > --- > mm/memcontrol.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 23d0f6e..43ca91d 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -536,15 +536,15 @@ void sock_update_memcg(struct sock *sk) > */ > if (sk->sk_cgrp) { > BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg)); > - mem_cgroup_get(sk->sk_cgrp->memcg); > + css_get(&sk->sk_cgrp->memcg->css); > return; > } > > rcu_read_lock(); > memcg = mem_cgroup_from_task(current); > cg_proto = sk->sk_prot->proto_cgroup(memcg); > - if (!mem_cgroup_is_root(memcg) && memcg_proto_active(cg_proto)) { > - mem_cgroup_get(memcg); > + if (!mem_cgroup_is_root(memcg) && > + memcg_proto_active(cg_proto) && css_tryget(&memcg->css)) { > sk->sk_cgrp = cg_proto; > } > rcu_read_unlock(); > @@ -558,7 +558,7 @@ void sock_release_memcg(struct sock *sk) > struct mem_cgroup *memcg; > WARN_ON(!sk->sk_cgrp->memcg); > memcg = sk->sk_cgrp->memcg; > - mem_cgroup_put(memcg); > + css_put(&sk->sk_cgrp->memcg->css); > } > } > > -- > 1.8.0.2 -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/