From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753630Ab3IWI5F (ORCPT ); Mon, 23 Sep 2013 04:57:05 -0400 Received: from szxga01-in.huawei.com ([119.145.14.64]:3070 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753550Ab3IWI5D (ORCPT ); Mon, 23 Sep 2013 04:57:03 -0400 Message-ID: <5240023D.6040606@huawei.com> Date: Mon, 23 Sep 2013 16:56:29 +0800 From: Li Zefan User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: Andrew Morton CC: Tejun Heo , Michal Hocko , "KAMEZAWA Hiroyuki" , Johannes Weiner , LKML , cgroups , "linux-mm@kvack.org" Subject: [PATCH v6 3/5] memcg: fail to create cgroup if the cgroup id is too big References: <524001F8.6070205@huawei.com> In-Reply-To: <524001F8.6070205@huawei.com> Content-Type: text/plain; charset="GB2312" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.135.68.215] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org memcg requires the cgroup id to be smaller than 65536. This is a preparation to kill css id. Signed-off-by: Li Zefan Acked-by: Michal Hocko --- mm/memcontrol.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 6719e2c..4e40ebe 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -498,6 +498,12 @@ static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) return (memcg == root_mem_cgroup); } +/* + * We restrict the id in the range of [1, 65535], so it can fit into + * an unsigned short. + */ +#define MEM_CGROUP_ID_MAX USHRT_MAX + static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg) { /* @@ -6312,6 +6318,9 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css) struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(css)); int error = 0; + if (css->cgroup->id > MEM_CGROUP_ID_MAX) + return -ENOSPC; + if (!parent) return 0; -- 1.8.0.2