+ kselftests-memcg-update-the-oom-group-leaf-events-test.patch added to -mm tree

+ kselftests-memcg-update-the-oom-group-leaf-events-test.patch added to -mm tree

[Andrew Morton]

The patch titled
     Subject: kselftests: memcg: update the oom group leaf events test
has been added to the -mm tree.  Its filename is
     kselftests-memcg-update-the-oom-group-leaf-events-test.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/kselftests-memcg-update-the-oom-group-leaf-events-test.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/kselftests-memcg-update-the-oom-group-leaf-events-test.patch

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------------------------------------------------------
From: Roman Gushchin <roman.gushchin@linux.dev>
Subject: kselftests: memcg: update the oom group leaf events test

Patch series "mm: memcg kselftests fixes".


This patch (of 4):

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.

Link: https://lkml.kernel.org/r/20220415000133.3955987-2-roman.gushchin@linux.dev
Link: https://lkml.kernel.org/r/20220415000133.3955987-1-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: David Vernet <void@manifault.com>
Cc: Chris Down <chris@chrisdown.name>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 tools/testing/selftests/cgroup/test_memcontrol.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/tools/testing/selftests/cgroup/test_memcontrol.c~kselftests-memcg-update-the-oom-group-leaf-events-test
+++ a/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -1079,7 +1079,8 @@ cleanup:
 /*
  * 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_eve
 	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;
_

Patches currently in -mm which might be from roman.gushchin@linux.dev are

kselftests-memcg-update-the-oom-group-leaf-events-test.patch
kselftests-memcg-speed-up-the-memoryhigh-test.patch
maintainers-add-corresponding-kselftests-to-cgroup-entry.patch
maintainers-add-corresponding-kselftests-to-memcg-entry.patch
mm-do-not-call-add_nr_deferred-with-zero-deferred.patch