Muhammad,
I am sorry, but... are you aware that this patch was applied over a year ago,
and then this code was updated to use the ksft_API?
Oleg.
On 04/07, Muhammad Usama Anjum wrote:
>
> On 3/16/23 5:30 PM, Marco Elver wrote:
> > From: Dmitry Vyukov <dvyu...@google.com>
> >
> > Test that POSIX timers using CLOCK_PROCESS_CPUTIME_ID eventually deliver
> > a signal to all running threads. This effectively tests that the kernel
> > doesn't prefer any one thread (or subset of threads) for signal delivery.
> >
> > Signed-off-by: Dmitry Vyukov <dvyu...@google.com>
> > Signed-off-by: Marco Elver <el...@google.com>
> > ---
> > v6:
> > - Update wording on what the test aims to test.
> > - Fix formatting per checkpatch.pl.
> > ---
> > tools/testing/selftests/timers/posix_timers.c | 77 +++++++++++++++++++
> > 1 file changed, 77 insertions(+)
> >
> > diff --git a/tools/testing/selftests/timers/posix_timers.c
> > b/tools/testing/selftests/timers/posix_timers.c
> > index 0ba500056e63..8a17c0e8d82b 100644
> > --- a/tools/testing/selftests/timers/posix_timers.c
> > +++ b/tools/testing/selftests/timers/posix_timers.c
> > @@ -188,6 +188,80 @@ static int check_timer_create(int which)
> > return 0;
> > }
> >
> > +int remain;
> > +__thread int got_signal;
> > +
> > +static void *distribution_thread(void *arg)
> > +{
> > + while (__atomic_load_n(&remain, __ATOMIC_RELAXED));
> > + return NULL;
> > +}
> > +
> > +static void distribution_handler(int nr)
> > +{
> > + if (!__atomic_exchange_n(&got_signal, 1, __ATOMIC_RELAXED))
> > + __atomic_fetch_sub(&remain, 1, __ATOMIC_RELAXED);
> > +}
> > +
> > +/*
> > + * Test that all running threads _eventually_ receive
> > CLOCK_PROCESS_CPUTIME_ID
> > + * timer signals. This primarily tests that the kernel does not favour any
> > one.
> > + */
> > +static int check_timer_distribution(void)
> > +{
> > + int err, i;
> > + timer_t id;
> > + const int nthreads = 10;
> > + pthread_t threads[nthreads];
> > + 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,
> > + };
> > +
> > + printf("Check timer_create() per process signal distribution... ");
> Use APIs from kselftest.h. Use ksft_print_msg() here.
>
> > + fflush(stdout);
> > +
> > + remain = nthreads + 1; /* worker threads + this thread */
> > + signal(SIGALRM, distribution_handler);
> > + err = timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &id);
> > + if (err < 0) {
> > + perror("Can't create timer\n");
> ksft_perror() here
>
> > + return -1;
> > + }
> > + err = timer_settime(id, 0, &val, NULL);
> > + if (err < 0) {
> > + perror("Can't set timer\n");
> > + return -1;
> > + }
> > +
> > + for (i = 0; i < nthreads; i++) {
> > + if (pthread_create(&threads[i], NULL, distribution_thread,
> > NULL)) {
> > + perror("Can't create thread\n");
> > + return -1;
> > + }
> > + }
> > +
> > + /* Wait for all threads to receive the signal. */
> > + while (__atomic_load_n(&remain, __ATOMIC_RELAXED));
> > +
> > + for (i = 0; i < nthreads; i++) {
> > + if (pthread_join(threads[i], NULL)) {
> > + perror("Can't join thread\n");
> > + return -1;
> > + }
> > + }
> > +
> > + if (timer_delete(id)) {
> > + perror("Can't delete timer\n");
> > + return -1;
> > + }
> > +
> > + printf("[OK]\n");
> ksft_test_result or _pass variant as needed?
>
> > + return 0;
> > +}
> > +
> > int main(int argc, char **argv)
> > {
> > printf("Testing posix timers. False negative may happen on CPU
> > execution \n");
> > @@ -217,5 +291,8 @@ int main(int argc, char **argv)
> > if (check_timer_create(CLOCK_PROCESS_CPUTIME_ID) < 0)
> > return ksft_exit_fail();
> >
> > + if (check_timer_distribution() < 0)
> > + return ksft_exit_fail();
> > +
> > return ksft_exit_pass();
> > }
>
> --
> BR,
> Muhammad Usama Anjum
>
