From: Hui Zhu <hui.zhu@linux.dev>
To: Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Roman Gushchin <roman.gushchin@linux.dev>,
Shakeel Butt <shakeel.butt@linux.dev>,
Muchun Song <muchun.song@linux.dev>,
Andrew Morton <akpm@linux-foundation.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>,
Eduard Zingerman <eddyz87@gmail.com>, Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>,
Stanislav Fomichev <sdf@fomichev.me>, Hao Luo <haoluo@google.com>,
Jiri Olsa <jolsa@kernel.org>, Shuah Khan <shuah@kernel.org>,
Hui Zhu <zhuhui@kylinos.cn>, JP Kobryn <inwardvessel@gmail.com>,
cgroups@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
linux-kselftest@vger.kernel.org
Subject: [PATCH bpf-next v2 2/3] selftests/bpf: Check bpf_mem_cgroup_page_state return value
Date: Fri, 13 Feb 2026 15:23:40 +0800 [thread overview]
Message-ID: <ba61b77c71b6285eefa022a84bf80c5913b313de.1770965805.git.zhuhui@kylinos.cn> (raw)
In-Reply-To: <cover.1770965805.git.zhuhui@kylinos.cn>
From: Hui Zhu <zhuhui@kylinos.cn>
When back-porting test_progs to different kernel versions, I encountered
an issue where the test_cgroup_iter_memcg test would falsely pass even
when bpf_mem_cgroup_page_state() failed.
This patch adds explicit checks to ensure bpf_mem_cgroup_page_state()
doesn't return -1 before validating the actual statistics values.
Signed-off-by: Hui Zhu <zhuhui@kylinos.cn>
---
.../selftests/bpf/prog_tests/cgroup_iter_memcg.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_iter_memcg.c b/tools/testing/selftests/bpf/prog_tests/cgroup_iter_memcg.c
index a5afd16705f0..897b17b58df3 100644
--- a/tools/testing/selftests/bpf/prog_tests/cgroup_iter_memcg.c
+++ b/tools/testing/selftests/bpf/prog_tests/cgroup_iter_memcg.c
@@ -53,6 +53,8 @@ static void test_anon(struct bpf_link *link, struct memcg_query *memcg_query)
if (!ASSERT_OK(read_stats(link), "read stats"))
goto cleanup;
+ ASSERT_NEQ(memcg_query->nr_anon_mapped, (unsigned long)-1,
+ "bpf_mem_cgroup_page_state NR_ANON_MAPPED");
ASSERT_GT(memcg_query->nr_anon_mapped, 0, "final anon mapped val");
cleanup:
@@ -88,6 +90,10 @@ static void test_file(struct bpf_link *link, struct memcg_query *memcg_query)
if (!ASSERT_OK(read_stats(link), "read stats"))
goto cleanup_map;
+ ASSERT_NEQ(memcg_query->nr_file_pages, (unsigned long)-1,
+ "bpf_mem_cgroup_page_state NR_FILE_PAGES");
+ ASSERT_NEQ(memcg_query->nr_file_mapped, (unsigned long)-1,
+ "bpf_mem_cgroup_page_state NR_FILE_MAPPED");
ASSERT_GT(memcg_query->nr_file_pages, 0, "final file value");
ASSERT_GT(memcg_query->nr_file_mapped, 0, "final file mapped value");
@@ -119,6 +125,8 @@ static void test_shmem(struct bpf_link *link, struct memcg_query *memcg_query)
if (!ASSERT_OK(read_stats(link), "read stats"))
goto cleanup;
+ ASSERT_NEQ(memcg_query->nr_shmem, (unsigned long)-1,
+ "bpf_mem_cgroup_page_state NR_SHMEM");
ASSERT_GT(memcg_query->nr_shmem, 0, "final shmem value");
cleanup:
@@ -143,6 +151,8 @@ static void test_kmem(struct bpf_link *link, struct memcg_query *memcg_query)
if (!ASSERT_OK(read_stats(link), "read stats"))
goto cleanup;
+ ASSERT_NEQ(memcg_query->memcg_kmem, (unsigned long)-1,
+ "bpf_mem_cgroup_vm_events MEMCG_KMEM");
ASSERT_GT(memcg_query->memcg_kmem, 0, "kmem value");
cleanup:
@@ -170,6 +180,8 @@ static void test_pgfault(struct bpf_link *link, struct memcg_query *memcg_query)
if (!ASSERT_OK(read_stats(link), "read stats"))
goto cleanup;
+ ASSERT_NEQ(memcg_query->pgfault, (unsigned long)-1,
+ "bpf_mem_cgroup_page_state PGFAULT");
ASSERT_GT(memcg_query->pgfault, 0, "final pgfault val");
cleanup:
--
2.43.0
next prev parent reply other threads:[~2026-02-13 7:24 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-13 7:23 [PATCH bpf-next v2 0/3] Fix test_cgroup_iter_memcg issues found during back-porting Hui Zhu
2026-02-13 7:23 ` [PATCH bpf-next v2 1/3] bpf: Use bpf_core_enum_value for stats in cgroup_iter_memcg Hui Zhu
2026-02-16 18:30 ` JP Kobryn (Meta)
2026-02-13 7:23 ` Hui Zhu [this message]
2026-02-13 7:56 ` [PATCH bpf-next v2 2/3] selftests/bpf: Check bpf_mem_cgroup_page_state return value bot+bpf-ci
2026-02-13 7:23 ` [PATCH bpf-next v2 3/3] bpf: selftests: Skip kmem test when cgroup.memory=nokmem is set Hui Zhu
2026-02-13 7:56 ` bot+bpf-ci
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