period            123 include/sys/prex.h int	timer_periodic(thread_t t, u_long start, u_long period);
period            240 sys/kern/timer.c timer_periodic(thread_t t, u_long start, u_long period)
period            245 sys/kern/timer.c 	if (start != 0 && period == 0)
period            287 sys/kern/timer.c 		tmr->interval = mstohz(period);