Hello Eric, > Also make sure you have commit a181ceb501b31b4bf8812a5c84c716cc31d82c2d > ("tcp: autocork should not hold first packet in write queue") > in your tree. confirmed: (node-62) [~/work/linux-2.6] git show a181ceb501b31b4bf8812a5c84c716cc31d82c2d | head commit a181ceb501b31b4bf8812a5c84c716cc31d82c2d Author: Eric Dumazet <edumazet@xxxxxxxxxx> Date: Tue Dec 17 09:58:30 2013 -0800 tcp: autocork should not hold first packet in write queue Willem noticed a TCP_RR regression caused by TCP autocorking on a Mellanox test bed. MLX4_EN_TX_COAL_TIME is 16 us, which can be right above RTT between hosts. Cheers, Thomas -- To unsubscribe from this list: send the line "unsubscribe target-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html