mm, hugetlb_cgroup: align hugetlb cgroup limit to hugepage size

mm, hugetlb_cgroup: align hugetlb cgroup limit to hugepage size

Memcg aligns memory.limit_in_bytes to PAGE_SIZE as part of the resource
counter since it makes no sense to allow a partial page to be charged.

As a result of the hugetlb cgroup using the resource counter, it is also
aligned to PAGE_SIZE but makes no sense unless aligned to the size of
the hugepage being limited.

Align hugetlb cgroup limit to hugepage size.

Signed-off-by: David Rientjes <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: "Aneesh Kumar K.V" <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Li Zefan <[email protected]>
Cc: Michal Hocko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>