v5:
 - Use mem_cgroup_usage() as originally suggested by Johannes.

v4:
 - Add "#ifdef CONFIG_MEMCG" directives around shrink_node_memcgs() to
   avoid compilation problem with !CONFIG_MEMCG configs.

The test_memcontrol selftest consistently fails its test_memcg_low
sub-test and sporadically fails its test_memcg_min sub-test. This
patchset fixes the test_memcg_min and test_memcg_low failures by
skipping the !usage case in shrink_node_memcgs() and adjust the
test_memcontrol selftest to fix other causes of the test failures.

Waiman Long (2):
  mm/vmscan: Skip memcg with !usage in shrink_node_memcgs()
  selftests: memcg: Increase error tolerance of child memory.current
    check in test_memcg_protection()

 mm/internal.h                                    |  9 +++++++++
 mm/memcontrol-v1.h                               |  2 --
 mm/vmscan.c                                      |  4 ++++
 tools/testing/selftests/cgroup/test_memcontrol.c | 11 ++++++++---
 4 files changed, 21 insertions(+), 5 deletions(-)

-- 
2.48.1