int main(int argc, char** argv)
{
struct timeval start_tv = {0};
struct timeval end_tv = {0};
long usec_diff;
long nr_ctx_switches;
void *join_ret;
if (argc > 1)
nr_switch_loops = strtol(argv[1], 0, 10);
printf("Making 2 threads of %d switches each\n", nr_switch_loops);
pthread_can_vcore_request(FALSE); /* 2LS won't manage vcores */
pthread_need_tls(FALSE);
pthread_lib_init(); /* gives us one vcore */
/* each is passed the other's pthread_t. th1 starts the switching. */
if (pthread_create(&th1, NULL, &switch_thread, &th2))
perror("pth_create 1 failed");
/* thread 2 is created, but not put on the runnable list */
if (__pthread_create(&th2, NULL, &switch_thread, &th1))
perror("pth_create 2 failed");
if (gettimeofday(&start_tv, 0))
perror("Start time error...");
ready = TRUE; /* signal to any spinning uthreads to start */
pthread_join(th1, &join_ret);
pthread_join(th2, &join_ret);
if (gettimeofday(&end_tv, 0))
perror("End time error...");
nr_ctx_switches = 2 * nr_switch_loops;
usec_diff = (end_tv.tv_sec - start_tv.tv_sec) * 1000000 +
(end_tv.tv_usec - start_tv.tv_usec);
printf("Done: %d loops\n", nr_switch_loops);
printf("Nr context switches: %ld\n", nr_ctx_switches);
printf("Time to run: %ld usec\n", usec_diff);
printf("Context switch latency: %d nsec\n",
(int)(1000LL*usec_diff / nr_ctx_switches));
printf("Context switches / sec: %d\n\n",
(int)(1000000LL*nr_ctx_switches / usec_diff));
}
int main(int argc, char** argv)
{
struct timeval start_tv = {0};
struct timeval end_tv = {0};
long usec_diff;
long nr_ctx_switches;
if (argc > 1)
nr_yield_threads = strtol(argv[1], 0, 10);
if (argc > 2)
nr_yield_loops = strtol(argv[2], 0, 10);
if (argc > 3)
nr_vcores = strtol(argv[3], 0, 10);
if (argc > 4)
amt_fake_work = strtol(argv[4], 0, 10);
nr_yield_threads = MIN(nr_yield_threads, MAX_NR_TEST_THREADS);
printf("Making %d threads of %d loops each, on %d vcore(s), %d work\n",
nr_yield_threads, nr_yield_loops, nr_vcores, amt_fake_work);
/* OS dependent prep work */
if (nr_vcores) {
/* Only do the vcore trickery if requested */
pthread_can_vcore_request(FALSE); /* 2LS won't manage vcores */
pthread_need_tls(FALSE);
pthread_lib_init(); /* gives us one vcore */
vcore_request(nr_vcores - 1); /* ghetto incremental interface */
for (int i = 0; i < nr_vcores; i++) {
printd("Vcore %d mapped to pcore %d\n", i,
__procinfo.vcoremap[i].pcoreid);
}
}
/* create and join on yield */
for (int i = 0; i < nr_yield_threads; i++) {
printf_safe("[A] About to create thread %d\n", i);
if (pthread_create(&my_threads[i], NULL, &yield_thread, NULL))
perror("pth_create failed");
}
if (gettimeofday(&start_tv, 0))
perror("Start time error...");
ready = TRUE; /* signal to any spinning uthreads to start */
for (int i = 0; i < nr_yield_threads; i++) {
printf_safe("[A] About to join on thread %d(%p)\n", i, my_threads[i]);
pthread_join(my_threads[i], &my_retvals[i]);
printf_safe("[A] Successfully joined on thread %d (retval: %p)\n", i,
my_retvals[i]);
}
if (gettimeofday(&end_tv, 0))
perror("End time error...");
nr_ctx_switches = nr_yield_threads * nr_yield_loops;
usec_diff = (end_tv.tv_sec - start_tv.tv_sec) * 1000000 +
(end_tv.tv_usec - start_tv.tv_usec);
printf("Done: %d uthreads, %d loops, %d vcores, %d work\n",
nr_yield_threads, nr_yield_loops, nr_vcores, amt_fake_work);
printf("Nr context switches: %d\n", nr_ctx_switches);
printf("Time to run: %d usec\n", usec_diff);
if (nr_vcores == 1)
printf("Context switch latency: %d nsec\n",
(int)(1000LL*usec_diff / nr_ctx_switches));
printf("Context switches / sec: %d\n\n",
(int)(1000000LL*nr_ctx_switches / usec_diff));
}
