Commit 1c09f7d0 authored Nov 11, 2018 by Eric Dumazet Committed by David S. Miller Nov 11, 2018

tcp: do not try to defer skbs with eor mark (MSG_EOR)



Applications using MSG_EOR are giving a strong hint to TCP stack :

Subsequent sendmsg() can not append more bytes to skbs having
the EOR mark.

Do not try to TSO defer suchs skbs, there is really no hope.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 5e13a0d3

net/ipv4/tcp_output.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -1944,6 +1944,10 @@ static bool tcp_tso_should_defer(struct sock sk, struct sk_buff skb,
		if ((skb != tcp_write_queue_tail(sk)) && (limit >= skb->len))
		goto send_now;

		/* If this packet won't get more data, do not wait. */
		if (TCP_SKB_CB(skb)->eor)
		goto send_now;

		win_divisor = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_tso_win_divisor);
		if (win_divisor) {
		u32 chunk = min(tp->snd_wnd, tp->snd_cwnd * tp->mss_cache);