[TCP]: add tcp_slow_start helper

Move all the code that does linear TCP slowstart to one
inline function to ease later patch to add ABC support.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 6 deletions

diff --git a/net/ipv4/tcp_scalable.c b/net/ipv4/tcp_scalable.c
index a2fd25617d24..26d7486ee501 100644
--- a/net/ipv4/tcp_scalable.c
+++ b/net/ipv4/tcp_scalable.c
@@ -24,17 +24,16 @@ static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
         if (!tcp_is_cwnd_limited(sk, in_flight))
                 return;
 
-        if (tp->snd_cwnd <= tp->snd_ssthresh) {
-                tp->snd_cwnd++;
-        } else {
+        if (tp->snd_cwnd <= tp->snd_ssthresh)
+                tcp_slow_start(tp);
+        else {
                 tp->snd_cwnd_cnt++;
                 if (tp->snd_cwnd_cnt > min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT)){
-                        tp->snd_cwnd++;
+                        if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+                                tp->snd_cwnd++;
                         tp->snd_cwnd_cnt = 0;
                 }
         }
-        tp->snd_cwnd = min_t(u32, tp->snd_cwnd, tp->snd_cwnd_clamp);
-        tp->snd_cwnd_stamp = tcp_time_stamp;
 }
 
 static u32 tcp_scalable_ssthresh(struct sock *sk)