cake_ewma
q->avg_netoff = cake_ewma(q->avg_netoff, off << 16, 8);
cake_ewma(q->avg_packet_interval,
cake_ewma(q->avg_peak_bandwidth, b,
b->avge_delay = cake_ewma(b->avge_delay, delay, 8);
b->peak_delay = cake_ewma(b->peak_delay, delay,
b->base_delay = cake_ewma(b->base_delay, delay,