[PATCH 1/4] kselftests: memcg: update the oom group leaf events test

From: Roman Gushchin
Date: Thu Apr 14 2022 - 20:01:57 EST


Commit 9852ae3fe529 ("mm, memcg: consider subtrees in memory.events") made
memory.events recursive: all events are propagated upwards by the
tree. It was a change in semantics.

It broke the oom group leaf events test: it assumes that after
an OOM the oom_kill counter is zero on parent's level.

Let's adjust the test: it should have similar expectations
for the child and parent levels.

The test passes after this fix.

Signed-off-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Cc: Chris Down <chris@xxxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
---
tools/testing/selftests/cgroup/test_memcontrol.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
index 36ccf2322e21..00b430e7f2a2 100644
--- a/tools/testing/selftests/cgroup/test_memcontrol.c
+++ b/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -1079,7 +1079,8 @@ static int test_memcg_sock(const char *root)
/*
* This test disables swapping and tries to allocate anonymous memory
* up to OOM with memory.group.oom set. Then it checks that all
- * processes in the leaf (but not the parent) were killed.
+ * processes in the leaf were killed. It also checks that oom_events
+ * were propagated to the parent level.
*/
static int test_memcg_oom_group_leaf_events(const char *root)
{
@@ -1122,7 +1123,7 @@ static int test_memcg_oom_group_leaf_events(const char *root)
if (cg_read_key_long(child, "memory.events", "oom_kill ") <= 0)
goto cleanup;

- if (cg_read_key_long(parent, "memory.events", "oom_kill ") != 0)
+ if (cg_read_key_long(parent, "memory.events", "oom_kill ") <= 0)
goto cleanup;

ret = KSFT_PASS;
--
2.35.1