selftests/cgroup: enable memory controller in hugetlb memcg test

test_hugetlb_memcg creates a child cgroup and then writes memory.max and
memory.swap.max. When the test is run standalone, the memory controller
may not be enabled in the test root cgroup's subtree_control.

In that case, the child cgroup is created without the memory control
files, and the test fails during setup before reaching the hugetlb memcg
accounting checks.

Skip the test when the memory controller is unavailable. Otherwise, enable
it in subtree_control before creating the test cgroup.

Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

0 files changed, 0 insertions, 0 deletions