_sched_getaffinity
return _sched_getaffinity(pid, P_ALL_LWPS, size, cpuset);
if (_sched_getaffinity(getpid(), thread->pt_lid, size, cpuset) < 0)
int _sched_getaffinity(pid_t, lwpid_t, size_t, cpuset_t *);
error = _sched_getaffinity(pid, lid, cpuset_size(cpuset), cpuset);