pid_t eat_cpu(int (test_function)(void))
{
union pipe read_pipe, write_pipe;
int cpu, rc;
pid_t pid;
cpu = pick_online_cpu();
FAIL_IF(cpu < 0);
FAIL_IF(bind_to_cpu(cpu));
if (pipe(read_pipe.fds) == -1)
return -1;
if (pipe(write_pipe.fds) == -1)
return -1;
pid = fork();
if (pid == 0)
exit(eat_cpu_child(write_pipe, read_pipe));
if (sync_with_child(read_pipe, write_pipe)) {
rc = -1;
goto out;
}
printf("main test running as pid %d\n", getpid());
rc = test_function();
out:
kill(pid, SIGKILL);
return rc;
}
int cpu_event_pinned_vs_ebb(void)
{
union pipe read_pipe, write_pipe;
struct event event;
int cpu, rc;
pid_t pid;
SKIP_IF(!ebb_is_supported());
cpu = pick_online_cpu();
FAIL_IF(cpu < 0);
FAIL_IF(bind_to_cpu(cpu));
FAIL_IF(pipe(read_pipe.fds) == -1);
FAIL_IF(pipe(write_pipe.fds) == -1);
pid = fork();
if (pid == 0) {
/* NB order of pipes looks reversed */
exit(ebb_child(write_pipe, read_pipe));
}
/* We setup the cpu event first */
rc = setup_cpu_event(&event, cpu);
if (rc) {
kill_child_and_wait(pid);
return rc;
}
/* Signal the child to install its EBB event and wait */
if (sync_with_child(read_pipe, write_pipe))
/* If it fails, wait for it to exit */
goto wait;
/* Signal the child to run */
FAIL_IF(sync_with_child(read_pipe, write_pipe));
wait:
/* We expect it to fail to read the event */
FAIL_IF(wait_for_child(pid) != 2);
FAIL_IF(event_disable(&event));
FAIL_IF(event_read(&event));
event_report(&event);
/* The cpu event should have run */
FAIL_IF(event.result.value == 0);
FAIL_IF(event.result.enabled != event.result.running);
return 0;
}
