Use RCU safe list operations for cgroup->children. This will be used
to implement cgroup children / descendant walking which can be used by
controllers.
Note that cgroup_create() now puts a new cgroup at the end of the
->children list instead of head. This isn't strictly necessary but is
done so that the iteration order is more conventional.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Li Zefan <lizefan@huawei.com>
eb6fd5040e