tcp: add helper for AI algorithm

It seems that implementation in yeah was inconsistent to what
other did as it would increase cwnd one ack earlier than the
others do.

Size benefits:

  bictcp_cong_avoid |  -36
  tcp_cong_avoid_ai |  +52
  bictcp_cong_avoid |  -34
  tcp_scalable_cong_avoid |  -36
  tcp_veno_cong_avoid |  -12
  tcp_yeah_cong_avoid |  -38

= -104 bytes total

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 6 deletions

diff --git a/net/ipv4/tcp_veno.c b/net/ipv4/tcp_veno.c
index d08b2e855c22..e9bbff746488 100644
--- a/net/ipv4/tcp_veno.c
+++ b/net/ipv4/tcp_veno.c
@@ -159,12 +159,7 @@ static void tcp_veno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight)
                                 /* In the "non-congestive state", increase cwnd
                                  *  every rtt.
                                  */
-                                if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
-                                        if (tp->snd_cwnd < tp->snd_cwnd_clamp)
-                                                tp->snd_cwnd++;
-                                        tp->snd_cwnd_cnt = 0;
-                                } else
-                                        tp->snd_cwnd_cnt++;
+                                tcp_cong_avoid_ai(tp, tp->snd_cwnd);
                         } else {
                                 /* In the "congestive state", increase cwnd
                                  * every other rtt.