tree f270436ae91d6a472efc425c256f487460e9b108
parent ec13b1d6f0a0457312e615335ce8ceb07da50a11
author Tejun Heo <tj@kernel.org> 1432329200 -0400
committer Jens Axboe <axboe@fb.com> 1433255613 -0600

memcg: add mem_cgroup_root_css

Add global mem_cgroup_root_css which points to the root memcg css.
This will be used by cgroup writeback support.  If memcg is disabled,
it's defined as ERR_PTR(-EINVAL).

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
aCc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>