Any comments? thanks.
Best Regards,
Jiafei.
> -----Original Message-----
> From: Jiafei Pan <jiafei.pan@xxxxxxx>
> Sent: Friday, March 26, 2021 5:44 PM
> To: williams@xxxxxxxxxx; jkacur@xxxxxxxxxx
> Cc: linux-rt-users@xxxxxxxxxxxxxxx; Jiafei Pan <jiafei.pan@xxxxxxx>; Jiafei
> Pan <jiafei.pan@xxxxxxx>
> Subject: [PATCH] rt-tests: pi_stress: fix testing threads' smp affinity
>
> This patch includes the following modification:
> 1. Make sure test threads and admin threads don't run on the same CPU
> Core if uniprocessor is not set or not on single Core platform to
> avoid starve admin threads.
> 2. Force to use SCHED_RR if more than one Groups running one a CPU
> Core to avoid test failure because threads in different Groups
> are using the same priority, SCHED_FIFO which is default policy
> and it maybe trigger deadlock of testing threads.
>
> Signed-off-by: Jiafei Pan <Jiafei.Pan@xxxxxxx>
> ---
> src/pi_tests/pi_stress.c | 23 +++++++++++++++++++----
> 1 file changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/src/pi_tests/pi_stress.c b/src/pi_tests/pi_stress.c index
> 49f89b7..8795908 100644
> --- a/src/pi_tests/pi_stress.c
> +++ b/src/pi_tests/pi_stress.c
> @@ -237,6 +237,13 @@ int main(int argc, char **argv)
> /* process command line arguments */
> process_command_line(argc, argv);
>
> + if (ngroups > (num_processors - 1)) {
> + printf("Warning: One Core will used for administor thread, the other
> CPU Core will run test thread,\n");
> + printf("\t it will running more than one Group on one Core (groups >
> num_of_processors -1),\n");
> + printf("\t it will force to use SCHED_RR, or change groups number to
> be lower than %ld \n", num_processors);
> + policy = SCHED_RR;
> + }
> +
> /* set default sched attributes */
> setup_sched_config(policy);
>
> @@ -285,9 +292,17 @@ int main(int argc, char **argv)
> break;
> for (i = 0; i < ngroups; i++) {
> groups[i].id = i;
> - groups[i].cpu = core++;
> - if (core >= num_processors)
> - core = 0;
> + if (num_processors == 1 || uniprocessor) {
> + groups[i].cpu = 0;
> + } else {
> + groups[i].cpu = core;
> + /* Find next non-admin Core */
> + do {
> + core++;
> + if (core >= num_processors)
> + core = 0;
> + } while (CPU_ISSET(core, &admin_cpu_mask));
> + }
> if (create_group(&groups[i]) != SUCCESS)
> return FAILURE;
> }
> @@ -1143,7 +1158,7 @@ int create_group(struct group_parameters *group)
> CPU_ZERO(&mask);
> CPU_SET(group->cpu, &mask);
>
> - pi_debug("group %d bound to cpu %ld\n", group->id, group->cpu);
> + printf("group %d bound to cpu %ld\n", group->id, group->cpu);
>
> /* start the low priority thread */
> pi_debug("creating low priority thread\n");
> --
> 2.17.1
