From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx183.postini.com [74.125.245.183]) by kanga.kvack.org (Postfix) with SMTP id B8E5B6B0037 for ; Mon, 29 Jul 2013 03:08:44 -0400 (EDT) Message-ID: <51F614D4.6000703@huawei.com> Date: Mon, 29 Jul 2013 15:08:04 +0800 From: Li Zefan MIME-Version: 1.0 Subject: [PATCH v3 2/8] cgroup: document how cgroup IDs are assigned References: <51F614B2.6010503@huawei.com> In-Reply-To: <51F614B2.6010503@huawei.com> Content-Type: text/plain; charset="GB2312" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: Andrew Morton , Glauber Costa , KAMEZAWA Hiroyuki , Michal Hocko , Johannes Weiner , LKML , Cgroups , linux-mm@kvack.org As cgroup id has been used in netprio cgroup and will be used in memcg, it's important to make it clear how a cgroup id is allocated. For example, in netprio cgroup, the id is used as index of anarray. Signed-off-by: Li Zefan Reviewed-by: Michal Hocko --- include/linux/cgroup.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 2bd052d..8c107e9 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -161,7 +161,13 @@ struct cgroup_name { struct cgroup { unsigned long flags; /* "unsigned long" so bitops work */ - int id; /* idr allocated in-hierarchy ID */ + /* + * idr allocated in-hierarchy ID. + * + * The ID of the root cgroup is always 0, and a new cgroup + * will be assigned with a smallest available ID. + */ + int id; /* * We link our 'sibling' struct into our parent's 'children'. -- 1.8.0.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org