On 4/7/24 2:13 AM, Oleg Nesterov wrote:
> 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?
Sorry, didn't realized this is already applied. So this patch is already
applied and it has already been made compliant.
Thanks
>
> 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
>>
>
--
BR,
Muhammad Usama Anjum
