TOD_REF_FREQ
static long dtick_avg = TOD_REF_FREQ;
dtick_avg = TOD_REF_FREQ;
dtick_delta = (dtick_avg - TOD_REF_FREQ) /
(TOD_REF_FREQ >> 2);
dtick_avg = TOD_REF_FREQ;
#define TOD_STALL_THRESHOLD (TOD_REF_FREQ * 3 / 2)
#define TOD_JUMP_THRESHOLD (TOD_REF_FREQ / 2)