Re: [PATCH v2] selftests/cgroup: add user_usec sanity check in test_cpucg_nice

From: Tao Cui

Date: Thu Jul 30 2026 - 11:12:23 EST




在 2026/7/30 21:07, Shaojie Sun 写道:
> In test_cpucg_nice, after the child process exits, user_usec is
> read from cpu.stat but the value is not checked. Add a sanity check
> to ensure user_usec > 0, analogous to test_cpucg_stats(), so that
> the test fails early if CPU usage wasn't properly accounted.
>
> Signed-off-by: Shaojie Sun <sunshaojie@xxxxxxxxxx>
> ---
> v2: Instead of simply removing the unused user_usec read, add a sanity
> check (if user_usec <= 0, goto cleanup) analogous to test_cpucg_stats(),
> as suggested by Michal.
>
> tools/testing/selftests/cgroup/test_cpu.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/tools/testing/selftests/cgroup/test_cpu.c b/tools/testing/selftests/cgroup/test_cpu.c
> index 7a40d76b9548..5a44705ed3fd 100644
> --- a/tools/testing/selftests/cgroup/test_cpu.c
> +++ b/tools/testing/selftests/cgroup/test_cpu.c
> @@ -291,6 +291,8 @@ static int test_cpucg_nice(const char *root)
>
> user_usec = cg_read_key_long(cpucg, "cpu.stat", "user_usec");
> nice_usec = cg_read_key_long(cpucg, "cpu.stat", "nice_usec");
> + if (user_usec <= 0)
> + goto cleanup;
> if (!values_close_report(nice_usec, expected_nice_usec, 1))
> goto cleanup;
>
Acked-by: Tao Cui <cuitao@xxxxxxxxxx>