kern_clock_getcpuclockid2
error = kern_clock_getcpuclockid2(td, PAIR32TO64(id_t, uap->id),
error = kern_clock_getcpuclockid2(td, uap->id, uap->which, &clk_id);
int kern_clock_getcpuclockid2(struct thread *td, id_t id, int which,