timespec_diff_us
dbg_timediff = timespec_diff_us(start_time, dbg_time);
dbg_timediff = timespec_diff_us(end_time, dbg_time);
timediff = timespec_diff_us(start_time, end_time);
timediff = timespec_diff_us(start_time, end_time);
timediff = timespec_diff_us(start, end);
extern long long timespec_diff_us(struct timespec start, struct timespec end);
timediff = max_frequency * timespec_diff_us(time_start[cpu], time_end[cpu]);
time_diff = timespec_diff_us(time_start[cpu], time_end[cpu]);