mem_cgroup_usage() reports usage in pages for non-root cgroup, and in bytes
otherwise. Make it always in pages and update mem_cgroup_read() caller
which wants result in bytes.
https://jira.sw.ru/browse/PSBM-58993
Fixes: 1af99077c135 ("ms/mm: memcontrol: revert use of root_mem_cgroup
res_counter")
The commit is pushed to "branch-rh7-3.10.0-514.6.1.vz7.28.x-ovz" and will
appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-514.6.1.vz7.28.2
-->
commit 7e9a740f1e974b0a5d8236824c060ece43a59865
Author: Andrey Ryabinin
Date: Mon Jan 23 14:47:55 2017 +0400
mm/memcontr
uncharge_batch_list() doesn't know anything about shmem pages.
As a result shmem stat is constantly growing.
Teach uncharge_batch_list() to deal with shmem pages to fix that.
https://jira.sw.ru/browse/PSBM-58984
Fixes: 35e719e7f63d("ms/mm: memcontrol: use page lists for uncharge batching")
Signed-