On Sat, 6 Apr 2024 at 17:12, Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
>
> Dmitry, Thomas,
>
> To simplify the review I've attached the code with this patch applied below.
>
> Yes, this changes the "semantics" of check_timer_distribution(), perhaps it
> should be renamed.
>
> But I do not see a better approach, and in fact I think that
>
> Test that all running threads _eventually_ receive CLOCK_PROCESS_CPUTIME_ID
>
> is the wrong goal.
>
> Do you agree?
>
> Oleg.
> -------------------------------------------------------------------------------
>
> static pthread_t ctd_thread;
> static volatile int ctd_count, ctd_failed;
>
> static void ctd_sighandler(int sig)
> {
> if (pthread_self() != ctd_thread)
> ctd_failed = 1;
> ctd_count--;
> }
>
> static void *ctd_thread_func(void *arg)
> {
> struct itimerspec val = {
> .it_value.tv_sec = 0,
> .it_value.tv_nsec = 1000 * 1000,
> .it_interval.tv_sec = 0,
> .it_interval.tv_nsec = 1000 * 1000,
> };
> timer_t id;
>
> /* 1/10 seconds to ensure the leader sleeps */
> usleep(10000);
>
> ctd_count = 100;
> if (timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &id))
> return "Can't create timer";
> if (timer_settime(id, 0, &val, NULL))
> return "Can't set timer";
>
> while (ctd_count > 0 && !ctd_failed)
> ;
>
> if (timer_delete(id))
> return "Can't delete timer";
>
> return NULL;
> }
>
> /*
> * Test that only the running thread receives the timer signal.
> */
> static int check_timer_distribution(void)
> {
> const char *errmsg;
>
> signal(SIGALRM, ctd_sighandler);
>
> errmsg = "Can't create thread";
> if (pthread_create(&ctd_thread, NULL, ctd_thread_func, NULL))
> goto err;
>
> errmsg = "Can't join thread";
> if (pthread_join(ctd_thread, (void **)&errmsg) || errmsg)
> goto err;
>
> if (ctd_failed)
> ksft_test_result_skip("No signal distribution. Assuming old kernel\n");
Shouldn't the test fail here? The goal of a test is to fail when
things don't work.
I don't see any other ksft_test_result_fail() calls, and it does not
look that the test will hang on incorrect distribution.
> else
> ksft_test_result_pass("check signal distribution\n");
>
> return 0;
> err:
> ksft_print_msg(errmsg);
> return -1;
> }
>
