On 2/26/25 01:39, Sinadin Shan wrote:
> For kernels with CONFIG_SCHED_CORE=n, the sched selftest cs_prctl_test
> fails with "Not a core sched system" error. Change this to gracefully
> skip the test for systems with core scheduling disabled. Exiting early
> would also ensure failures reported in obtaining cookie are valid
> failures and not because core scheduling isn't supported.
>
> Skip cs_prctl_test for systems with CONFIG_SCHED_CORE=n
>
> Signed-off-by: Sinadin Shan <sinadin.shan@xxxxxxxxxx>
> ---
> tools/testing/selftests/sched/cs_prctl_test.c | 34 ++++++++++++++++++-
> 1 file changed, 33 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/sched/cs_prctl_test.c b/tools/testing/selftests/sched/cs_prctl_test.c
> index 52d97fae4dbd8..5b0047b50e640 100644
> --- a/tools/testing/selftests/sched/cs_prctl_test.c
> +++ b/tools/testing/selftests/sched/cs_prctl_test.c
> @@ -109,6 +109,36 @@ static void handle_usage(int rc, char *msg)
> exit(rc);
> }
>
> +static void check_core_sched(void)
> +{
> + unsigned long long cookie;
> + int ret, num_max_process;
> + char buffer[32];
> +
> + FILE *fp = fopen("/proc/sys/kernel/pid_max", "r");
> +
> + if (fp == NULL) {
> + perror("Failed to obtain max process number");
> + exit(EXIT_FAILURE);
> + }
> +
> + if (fgets(buffer, sizeof(buffer), fp) == NULL) {
> + fclose(fp);
> + exit(EXIT_FAILURE);
> + }
> +
> + num_max_process = atoi(buffer);
> + fclose(fp);
> +
> + ret = prctl(PR_SCHED_CORE, PR_SCHED_CORE_GET, num_max_process+1, PIDTYPE_PID,
> + (unsigned long)&cookie);
> + if (ret == -1 && errno != ESRCH) {
> + perror("prctl failed");
> + printf("Core sched not supported, hence skipping tests\n");
> + exit(4);
> + }
> +}
> +
> static unsigned long get_cs_cookie(int pid)
> {
> unsigned long long cookie;
> @@ -117,7 +147,7 @@ static unsigned long get_cs_cookie(int pid)
> ret = prctl(PR_SCHED_CORE, PR_SCHED_CORE_GET, pid, PIDTYPE_PID,
> (unsigned long)&cookie);
> if (ret) {
> - printf("Not a core sched system\n");
> + printf("Failed to get cookie\n");
> return -1UL;
> }
>
> @@ -270,6 +300,8 @@ int main(int argc, char *argv[])
> if (keypress)
> delay = -1;
>
> + check_core_sched();
> +
> srand(time(NULL));
>
> /* put into separate process group */
> --
> 2.43.5
So assuming a return code of 4 means skip (and I believe you stated that affirmatively before), then this
should solve the problem. Thanks for fixing this.
Reviewed-by: Chris Hyser <chris.hyser@xxxxxxxxxx>
-chrish
