V_dctcp_shift_g
dctcp_data->alpha = ulmin(alpha_prev - (alpha_prev >> V_dctcp_shift_g) +
((uint64_t)dctcp_data->bytes_ecn << (DCTCP_SHIFT - V_dctcp_shift_g)) /
new = V_dctcp_shift_g;
V_dctcp_shift_g = new;