tcp: Refactor pingpong code

Instead of using pingpong as a single bit information, we refactor the
code to treat it as a counter. When interactive session is detected,
we set pingpong count to TCP_PINGPONG_THRESH. And when pingpong count
is >= TCP_PINGPONG_THRESH, we consider the session in pingpong mode.

This patch is a pure refactor and sets foundation for the next patch.
This patch itself does not change any pingpong logic.

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 26a2948dca95..06228e2d010e 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -171,7 +171,7 @@ static void tcp_event_data_sent(struct tcp_sock *tp,
          * packet, enter pingpong mode.
          */
         if ((u32)(now - icsk->icsk_ack.lrcvtime) < icsk->icsk_ack.ato)
-                icsk->icsk_ack.pingpong = 1;
+                inet_csk_enter_pingpong_mode(sk);
 }
 
 /* Account for an ACK we sent. */
@@ -3569,7 +3569,7 @@ void tcp_send_delayed_ack(struct sock *sk)
                 const struct tcp_sock *tp = tcp_sk(sk);
                 int max_ato = HZ / 2;
 
-                if (icsk->icsk_ack.pingpong ||
+                if (inet_csk_in_pingpong_mode(sk) ||
                     (icsk->icsk_ack.pending & ICSK_ACK_PUSHED))
                         max_ato = TCP_DELACK_MAX;