[PATCH 6.4 154/800] selftests: cgroup: fix unexpected failure on test_memcg_low

Greg Kroah-Hartman
2023-07-16T20:00:00Z

From: Haifeng Xu <haifeng.xu@shopee.com>

[ Upstream commit 19ab365762c6cc39dfdee9e13ab0d12fe4b5540d ]

Since commit f079a020ba95 ("selftests: memcg: factor out common parts of
memory.{low,min} tests"), the value used in second alloc_anon has changed
from 148M to 170M. Because memory.low allows reclaiming page cache in
child cgroups, so the memory.current is close to 30M instead of 50M.
Therefore, adjust the expected value of parent cgroup.

Link: https://lkml.kernel.org/r/20230522095233.4246-2-haifeng.xu@shopee.com
Fixes: f079a020ba95 ("selftests: memcg: factor out common parts of memory.{low,min} tests")
Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/testing/selftests/cgroup/test_memcontrol.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
index f4f7c0aef702b..a2a90f4bfe9fe 100644
--- a/tools/testing/selftests/cgroup/test_memcontrol.c
+++ b/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -292,6 +292,7 @@ static int test_memcg_protection(const char *root, bool min)
char *children[4] = {NULL};
const char *attribute = min ? "memory.min" : "memory.low";
long c[4];
+ long current;
int i, attempts;
int fd;

@@ -400,7 +401,8 @@ static int test_memcg_protection(const char *root, bool min)
goto cleanup;
}

- if (!values_close(cg_read_long(parent[1], "memory.current"), MB(50), 3))
+ current = min ? MB(50) : MB(30);
+ if (!values_close(cg_read_long(parent[1], "memory.current"), current, 3))
goto cleanup;

if (!reclaim_until(children[0], MB(10)))
--
2.39.2