decay_load
sa->load_sum = decay_load(sa->load_sum, periods);
decay_load(sa->runnable_sum, periods);
sa->util_sum = decay_load((u64)(sa->util_sum), periods);
c1 = decay_load((u64)d1, periods);
c2 = LOAD_AVG_MAX - decay_load(LOAD_AVG_MAX, periods) - 1024;