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From:   =?UTF-8?q?Michal=20Koutn=C3=BD?= <mkoutny@suse.com>
To:     cgroups@vger.kernel.org, linux-mm@kvack.org
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Michal Hocko <mhocko@kernel.org>,
        Roman Gushchin <roman.gushchin@linux.dev>,
        Shakeel Butt <shakeelb@google.com>,
        linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
        Richard Palethorpe <rpalethorpe@suse.de>,
        Muhammad Usama Anjum <usama.anjum@collabora.com>
Subject: [PATCH v3 4/5] selftests: memcg: Remove protection from top level memcg
Date:   Tue, 24 May 2022 18:29:54 +0200
Message-Id: <20220524162955.8635-5-mkoutny@suse.com>
In-Reply-To: <20220524162955.8635-1-mkoutny@suse.com>
References: <20220524162955.8635-1-mkoutny@suse.com>
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Precedence: bulk

The reclaim is triggered by memory limit in a subtree, therefore the
testcase does not need configured protection against external reclaim.

Also, correct respective comments

Signed-off-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
---
 tools/testing/selftests/cgroup/test_memcontrol.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
index dc2c7d6e3572..63c6a683a8c1 100644
--- a/tools/testing/selftests/cgroup/test_memcontrol.c
+++ b/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -247,7 +247,7 @@ static int cg_test_proc_killed(const char *cgroup)
 
 /*
  * First, this test creates the following hierarchy:
- * A       memory.min = 50M,  memory.max = 200M
+ * A       memory.min = 0,    memory.max = 200M
  * A/B     memory.min = 50M
  * A/B/C   memory.min = 75M,  memory.current = 50M
  * A/B/D   memory.min = 25M,  memory.current = 50M
@@ -257,7 +257,7 @@ static int cg_test_proc_killed(const char *cgroup)
  * Usages are pagecache, but the test keeps a running
  * process in every leaf cgroup.
  * Then it creates A/G and creates a significant
- * memory pressure in it.
+ * memory pressure in A.
  *
  * Then it checks actual memory usages and expects that:
  * A/B    memory.current ~= 50M
@@ -338,8 +338,6 @@ static int test_memcg_min(const char *root)
 			      (void *)(long)fd);
 	}
 
-	if (cg_write(parent[0], "memory.min", "50M"))
-		goto cleanup;
 	if (cg_write(parent[1], "memory.min", "50M"))
 		goto cleanup;
 	if (cg_write(children[0], "memory.min", "75M"))
@@ -407,7 +405,7 @@ static int test_memcg_min(const char *root)
 
 /*
  * First, this test creates the following hierarchy:
- * A       memory.low = 50M,  memory.max = 200M
+ * A       memory.low = 0,    memory.max = 200M
  * A/B     memory.low = 50M
  * A/B/C   memory.low = 75M,  memory.current = 50M
  * A/B/D   memory.low = 25M,  memory.current = 50M
@@ -495,8 +493,6 @@ static int test_memcg_low(const char *root)
 			goto cleanup;
 	}
 
-	if (cg_write(parent[0], "memory.low", "50M"))
-		goto cleanup;
 	if (cg_write(parent[1], "memory.low", "50M"))
 		goto cleanup;
 	if (cg_write(children[0], "memory.low", "75M"))
-- 
2.35.3