cpu_ticks_delta
uint64_t cpu_ticks_delta(kstat_t *old, kstat_t *new);
getime = cpu_ticks_delta(oldks,
ticks = cpu_ticks_delta(old_sys, &c2->cs_sys);
return (cpu_ticks_delta(old, new));
etime = cpu_ticks_delta(oldsys, newsys);