diff options
| author | Li Zefan <lizefan@huawei.com> | 2013-07-31 09:51:06 +0800 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2013-07-31 07:47:34 -0400 |
| commit | b414dc09a31d41d696093a4cce9fb2853a5ecd4e (patch) | |
| tree | 63cf081d600fff0d271130b8578f17d4fb90fe49 | |
| parent | 4e96ee8e981b5140a2bcc5fff0d5c0eef39a62ee (diff) | |
cgroup: document how cgroup IDs are assigned
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 <lizefan@huwei.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
| -rw-r--r-- | include/linux/cgroup.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index cca570e188f..4dfcd0e1b73 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'. |