From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758862Ab3GaBw6 (ORCPT ); Tue, 30 Jul 2013 21:52:58 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:48488 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751381Ab3GaBwy (ORCPT ); Tue, 30 Jul 2013 21:52:54 -0400 Message-ID: <51F86DDD.3030809@huawei.com> Date: Wed, 31 Jul 2013 09:52:29 +0800 From: Li Zefan User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/20130620 Thunderbird/17.0.7 MIME-Version: 1.0 To: Tejun Heo CC: Andrew Morton , Glauber Costa , KAMEZAWA Hiroyuki , Michal Hocko , Johannes Weiner , LKML , Cgroups , Subject: [PATCH v4 6/8] memcg: fail to create cgroup if the cgroup id is too big References: <51F86D69.2030907@huawei.com> In-Reply-To: <51F86D69.2030907@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 62541f5..ad7d7c9 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -512,6 +512,12 @@ 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) { /* @@ -6248,6 +6254,9 @@ mem_cgroup_css_alloc(struct cgroup *cont) long error = -ENOMEM; int node; + if (cont->id > MEM_CGROUP_ID_MAX) + return ERR_PTR(-ENOSPC); + memcg = mem_cgroup_alloc(); if (!memcg) return ERR_PTR(error); -- 1.8.0.2