do_measure
old_tsc1 = do_measure(timer_latency, &start_lat1, &start1,
old_tsc2 = do_measure(timer_latency, &start_lat2, &start2,
new_tsc1 = do_measure(timer_latency, &end_lat1, &end1,
new_tsc2 = do_measure(timer_latency, &end_lat2, &end2,