[PATCH 09/12] cgroup: add css_set->dfl_cgrp

To implement the unified hierarchy behavior, we'll need to be able to determine the associated cgroup on the default hierarchy from css_set. Let's add css_set->dfl_cgrp so that it can be accessed conveniently and efficiently. Signed-off-by: Tejun Heo --- include/linux/cgroup.h | 3 +++ kernel/cg

[PATCH 09/12] cgroup: add css_set->dfl_cgrp

To implement the unified hierarchy behavior, we'll need to be able to determine the associated cgroup on the default hierarchy from css_set. Let's add css_set->dfl_cgrp so that it can be accessed conveniently and efficiently. Signed-off-by: Tejun Heo --- include/linux/cgroup.h | 3 +++ kernel/cg