v3: - Take up Johannes' suggestion of just skip the !usage case and fix test_memcontrol selftest to fix the rests of the min/low failures.
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.
Note that I decide not to use the suggested mem_cgroup_usage() call as it is a real function call defined in mm/memcontrol.c which is not available if CONFIG_MEMCG isn't defined.
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/vmscan.c | 4 ++++ tools/testing/selftests/cgroup/test_memcontrol.c | 11 ++++++++--- 2 files changed, 12 insertions(+), 3 deletions(-)