_HIST_SIZE
static int bytes_avg_history[_HIST_SIZE] = {0};
static int d_avg_history[_HIST_SIZE] = {0};
for (i = 0; i < _HIST_SIZE; i++)
history_idx %= _HIST_SIZE;
for (i = 0; i < _HIST_SIZE; i++) {
bytes_hist /= _HIST_SIZE;
d_hist /= _HIST_SIZE;