Re: [PATCH bpf-next 3/3] selftests/bpf: Skip test_kmem when cgroup.memory=nokmem

["JP Kobryn (Meta)" <inwardvessel@gmail.com>]

On 2/12/26 12:23 AM, Hui Zhu wrote:
> From: Hui Zhu <zhuhui@kylinos.cn>
> 
> When cgroup.memory=nokmem is set in kernel command line, kmem
> accounting is disabled and the test_kmem subtest will fail.
> 
> Add a check to skip this test when the parameter is present.
> 
> Signed-off-by: Hui Zhu <zhuhui@kylinos.cn>
> ---
>   .../bpf/prog_tests/cgroup_iter_memcg.c        | 28 +++++++++++++++++++
>   1 file changed, 28 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 13b299512429..203e6b091a21 100644
> --- a/tools/testing/selftests/bpf/prog_tests/cgroup_iter_memcg.c
> +++ b/tools/testing/selftests/bpf/prog_tests/cgroup_iter_memcg.c
> @@ -134,11 +134,39 @@ static void test_shmem(struct bpf_link *link, struct memcg_query *memcg_query)
>   	shm_unlink("/tmp_shmem");
>   }
>   
> +static bool cmdline_has(const char *arg)
> +{
> +	char cmdline[4096];
> +	int fd;
> +	ssize_t len;
> +	bool ret = false;
> +
> +	fd = open("/proc/cmdline", O_RDONLY);
> +	if (fd < 0)
> +		return false;
> +
> +	len = read(fd, cmdline, sizeof(cmdline) - 1);
> +	close(fd);
> +	if (len < 0)
> +		return false;
> +
> +	cmdline[len] = '\0';
> +	if (strstr(cmdline, arg))
> +		ret = true;
> +
> +	return ret;
> +}
> +
>   #define NR_PIPES 64
>   static void test_kmem(struct bpf_link *link, struct memcg_query *memcg_query)
>   {
>   	int fds[NR_PIPES][2], i;
>   
> +	if (cmdline_has("cgroup.memory=nokmem")) {
> +		test__skip();
> +		return;
> +	}

Instead of just skipping what if we proceed and then confirm we get a
zero value after the allocations?