tcp: avoid resetting ACK timer in DCTCP

The recent fix of acking immediately in DCTCP on CE status change
has an undesirable side-effect: it also resets TCP ack timer and
disables pingpong mode (interactive session). But the CE status
change has nothing to do with them. This patch addresses that by
using the new one-time immediate ACK flag instead of calling
tcp_enter_quickack_mode().

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Yuchung Cheng 2018-08-09 09:38:10 -07:00 committed by David S. Miller
parent 466466dc6c
commit d2ccd7bc8a

View File

@ -136,7 +136,7 @@ static void dctcp_ce_state_0_to_1(struct sock *sk)
*/ */
if (inet_csk(sk)->icsk_ack.pending & ICSK_ACK_TIMER) if (inet_csk(sk)->icsk_ack.pending & ICSK_ACK_TIMER)
__tcp_send_ack(sk, ca->prior_rcv_nxt); __tcp_send_ack(sk, ca->prior_rcv_nxt);
tcp_enter_quickack_mode(sk, 1); inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_NOW;
} }
ca->prior_rcv_nxt = tp->rcv_nxt; ca->prior_rcv_nxt = tp->rcv_nxt;
@ -157,7 +157,7 @@ static void dctcp_ce_state_1_to_0(struct sock *sk)
*/ */
if (inet_csk(sk)->icsk_ack.pending & ICSK_ACK_TIMER) if (inet_csk(sk)->icsk_ack.pending & ICSK_ACK_TIMER)
__tcp_send_ack(sk, ca->prior_rcv_nxt); __tcp_send_ack(sk, ca->prior_rcv_nxt);
tcp_enter_quickack_mode(sk, 1); inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_NOW;
} }
ca->prior_rcv_nxt = tp->rcv_nxt; ca->prior_rcv_nxt = tp->rcv_nxt;