diff options
| author | Tejun Heo <tj@kernel.org> | 2014-05-04 15:09:14 -0400 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2014-05-04 15:09:14 -0400 |
| commit | 15a4c835e4ed3e60dd68727cd1907e3dd89563f4 (patch) | |
| tree | 849cef1af88267720ec75def1c05ffe0f41e310e /include/linux/cgroup.h | |
| parent | ddfcadab35dda6e5bc23ccf1c3055ecb63a71e49 (diff) | |
cgroup, memcg: implement css->id and convert css_from_id() to use it
Until now, cgroup->id has been used to identify all the associated
csses and css_from_id() takes cgroup ID and returns the matching css
by looking up the cgroup and then dereferencing the css associated
with it; however, now that the lifetimes of cgroup and css are
separate, this is incorrect and breaks on the unified hierarchy when a
controller is disabled and enabled back again before the previous
instance is released.
This patch adds css->id which is a subsystem-unique ID and converts
css_from_id() to look up by the new css->id instead. memcg is the
only user of css_from_id() and also converted to use css->id instead.
For traditional hierarchies, this shouldn't make any functional
difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jianyu Zhan <nasa4836@gmail.com>
Acked-by: Li Zefan <lizefan@huawei.com>
Diffstat (limited to 'include/linux/cgroup.h')
| -rw-r--r-- | include/linux/cgroup.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 793f70a48820..2dfabb3b749a 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -62,6 +62,12 @@ struct cgroup_subsys_state { /* the parent css */ struct cgroup_subsys_state *parent; + /* + * Subsys-unique ID. 0 is unused and root is always 1. The + * matching css can be looked up using css_from_id(). + */ + int id; + unsigned int flags; /* percpu_ref killing and RCU release */ @@ -655,6 +661,9 @@ struct cgroup_subsys { /* link to parent, protected by cgroup_lock() */ struct cgroup_root *root; + /* idr for css->id */ + struct idr css_idr; + /* * List of cftypes. Each entry is the first entry of an array * terminated by zero length name. |