diff options
| author | Tejun Heo <tj@kernel.org> | 2014-05-04 21:09:13 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2014-05-04 21:09:13 +0200 |
| commit | 7d699ddb2b181a2c76e5ea18b1bdf102c4bebe4b (patch) | |
| tree | 0811810b37ff735921b689aa1ca273ecf253e29c /mm | |
| parent | cgroup: make flags and subsys_masks unsigned int (diff) | |
| download | linux-7d699ddb2b181a2c76e5ea18b1bdf102c4bebe4b.tar.xz linux-7d699ddb2b181a2c76e5ea18b1bdf102c4bebe4b.zip | |
cgroup, memcg: allocate cgroup ID from 1
Currently, cgroup->id is allocated from 0, which is always assigned to
the root cgroup; unfortunately, memcg wants to use ID 0 to indicate
invalid IDs and ends up incrementing all IDs by one.
It's reasonable to reserve 0 for special purposes. This patch updates
cgroup core so that ID 0 is not used and the root cgroups get ID 1.
The ID incrementing is removed form memcg.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memcontrol.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 29501f040568..1d0b29715b73 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -527,18 +527,14 @@ static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg) { - /* - * The ID of the root cgroup is 0, but memcg treat 0 as an - * invalid ID, so we return (cgroup_id + 1). - */ - return memcg->css.cgroup->id + 1; + return memcg->css.cgroup->id; } static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id) { struct cgroup_subsys_state *css; - css = css_from_id(id - 1, &memory_cgrp_subsys); + css = css_from_id(id, &memory_cgrp_subsys); return mem_cgroup_from_css(css); } |