tree bd2132cd966aaeaa91aaa5ca85cfc24f29061375
parent c26251f9f06d27d1941229d237aca44a0e7b4e42
author Michal Hocko <mhocko@suse.cz> 1351251449 +0200
committer Tejun Heo <tj@kernel.org> 1351552941 -0700

memcg: root_cgroup cannot reach mem_cgroup_move_parent

The root cgroup cannot be destroyed so we never hit it down the
mem_cgroup_pre_destroy path and mem_cgroup_force_empty_write shouldn't
even try to do anything if called for the root.

This means that mem_cgroup_move_parent doesn't have to bother with the
root cgroup and it can assume it can always move charges upwards.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Tejun Heo <tj@kernel.org>