From: "JP Kobryn (Meta)" <jp.kobryn@linux.dev>
To: Hui Zhu <hui.zhu@linux.dev>, 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>,
Roman Gushchin <roman.gushchin@linux.dev>,
bpf@vger.kernel.org, linux-kselftest@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: Hui Zhu <zhuhui@kylinos.cn>
Subject: Re: [PATCH bpf-next v4 1/3] selftests/bpf: Remove kmem subtest from cgroup_iter_memcg
Date: Mon, 2 Mar 2026 10:08:12 -0800 [thread overview]
Message-ID: <c28a79b5-2d9c-4ba9-8d78-384bbc0c05de@linux.dev> (raw)
In-Reply-To: <bb9c8fe74aba9dc8c3d803ea6caf6610e981d79a.1772270591.git.zhuhui@kylinos.cn>
On 2/28/26 1:25 AM, Hui Zhu wrote:
> From: Hui Zhu <zhuhui@kylinos.cn>
>
> When cgroup.memory=nokmem is set in the kernel command line, kmem
> accounting is disabled. This causes the test_kmem subtest in
> cgroup_iter_memcg to fail because it expects non-zero kmem values.
>
> Remove the kmem subtest altogether since the remaining subtests
> (shmem, file, pgfault) already provide sufficient coverage for
> the cgroup iter memcg functionality.
>
> Signed-off-by: Hui Zhu <zhuhui@kylinos.cn>
> ---
> .../testing/selftests/bpf/cgroup_iter_memcg.h | 2 --
> .../bpf/prog_tests/cgroup_iter_memcg.c | 28 -------------------
> .../selftests/bpf/progs/cgroup_iter_memcg.c | 1 -
> 3 files changed, 31 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/cgroup_iter_memcg.h b/tools/testing/selftests/bpf/cgroup_iter_memcg.h
> index 3f59b127943b..ff20ec537164 100644
> --- a/tools/testing/selftests/bpf/cgroup_iter_memcg.h
> +++ b/tools/testing/selftests/bpf/cgroup_iter_memcg.h
> @@ -9,8 +9,6 @@ struct memcg_query {
> unsigned long nr_shmem;
> unsigned long nr_file_pages;
> unsigned long nr_file_mapped;
> - /* some memcg_stat_item */
> - unsigned long memcg_kmem;
> /* some vm_event_item */
> unsigned long pgfault;
> };
> 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..88fc3e83d2b7 100644
> --- a/tools/testing/selftests/bpf/prog_tests/cgroup_iter_memcg.c
> +++ b/tools/testing/selftests/bpf/prog_tests/cgroup_iter_memcg.c
> @@ -126,32 +126,6 @@ static void test_shmem(struct bpf_link *link, struct memcg_query *memcg_query)
> shm_unlink("/tmp_shmem");
> }
>
> -#define NR_PIPES 64
> -static void test_kmem(struct bpf_link *link, struct memcg_query *memcg_query)
> -{
> - int fds[NR_PIPES][2], i;
> -
> - /*
> - * Increase kmem value by creating pipes which will allocate some
> - * kernel buffers.
> - */
> - for (i = 0; i < NR_PIPES; i++) {
> - if (!ASSERT_OK(pipe(fds[i]), "pipe"))
> - goto cleanup;
> - }
> -
> - if (!ASSERT_OK(read_stats(link), "read stats"))
> - goto cleanup;
> -
> - ASSERT_GT(memcg_query->memcg_kmem, 0, "kmem value");
> -
> -cleanup:
> - for (i = i - 1; i >= 0; i--) {
> - close(fds[i][0]);
> - close(fds[i][1]);
> - }
> -}
> -
> static void test_pgfault(struct bpf_link *link, struct memcg_query *memcg_query)
> {
> void *map;
> @@ -209,8 +183,6 @@ void test_cgroup_iter_memcg(void)
> test_shmem(link, &skel->data_query->memcg_query);
> if (test__start_subtest("cgroup_iter_memcg__file"))
> test_file(link, &skel->data_query->memcg_query);
> - if (test__start_subtest("cgroup_iter_memcg__kmem"))
> - test_kmem(link, &skel->data_query->memcg_query);
> if (test__start_subtest("cgroup_iter_memcg__pgfault"))
> test_pgfault(link, &skel->data_query->memcg_query);
>
> diff --git a/tools/testing/selftests/bpf/progs/cgroup_iter_memcg.c b/tools/testing/selftests/bpf/progs/cgroup_iter_memcg.c
> index 59fb70a3cc50..12f79a44133e 100644
> --- a/tools/testing/selftests/bpf/progs/cgroup_iter_memcg.c
> +++ b/tools/testing/selftests/bpf/progs/cgroup_iter_memcg.c
> @@ -30,7 +30,6 @@ int cgroup_memcg_query(struct bpf_iter__cgroup *ctx)
> memcg_query.nr_shmem = bpf_mem_cgroup_page_state(memcg, NR_SHMEM);
> memcg_query.nr_file_pages = bpf_mem_cgroup_page_state(memcg, NR_FILE_PAGES);
> memcg_query.nr_file_mapped = bpf_mem_cgroup_page_state(memcg, NR_FILE_MAPPED);
> - memcg_query.memcg_kmem = bpf_mem_cgroup_page_state(memcg, MEMCG_KMEM);
> memcg_query.pgfault = bpf_mem_cgroup_vm_events(memcg, PGFAULT);
>
> bpf_put_mem_cgroup(memcg);
Reviewed-by: JP Kobryn <jp.kobryn@linux.dev>
next prev parent reply other threads:[~2026-03-02 18:08 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-28 9:25 [PATCH bpf-next v4 0/3] Fix test_cgroup_iter_memcg issues found during back-porting Hui Zhu
2026-02-28 9:25 ` [PATCH bpf-next v4 1/3] selftests/bpf: Remove kmem subtest from cgroup_iter_memcg Hui Zhu
2026-03-02 18:08 ` JP Kobryn (Meta) [this message]
2026-02-28 9:25 ` [PATCH bpf-next v4 2/3] bpf: Use bpf_core_enum_value for stats in cgroup_iter_memcg Hui Zhu
2026-03-02 18:10 ` JP Kobryn (Meta)
2026-02-28 9:25 ` [PATCH bpf-next v4 3/3] selftests/bpf: Check bpf_mem_cgroup_page_state return value Hui Zhu
2026-03-02 18:27 ` JP Kobryn (Meta)
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