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From:   Pengcheng Yang <yangpc@wangsu.com>
To:     edumazet@google.com, ncardwell@google.com, davem@davemloft.net
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Pengcheng Yang <yangpc@wangsu.com>
Subject: [PATCH RESEND net-next v2 3/5] tcp: stretch ACK fixes in Veno prep
Date:   Mon, 16 Mar 2020 14:35:09 +0800
Message-Id: <1584340511-9870-4-git-send-email-yangpc@wangsu.com>
In-Reply-To: <1584340511-9870-1-git-send-email-yangpc@wangsu.com>
References: <1584340511-9870-1-git-send-email-yangpc@wangsu.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

No code logic has been changed in this patch.

Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
---
 net/ipv4/tcp_veno.c | 44 +++++++++++++++++++++++---------------------
 1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/net/ipv4/tcp_veno.c b/net/ipv4/tcp_veno.c
index 3b36bb1..857491c 100644
--- a/net/ipv4/tcp_veno.c
+++ b/net/ipv4/tcp_veno.c
@@ -153,31 +153,33 @@ static void tcp_veno_cong_avoid(struct sock *sk, u32 ack, u32 acked)
 		veno->diff = (tp->snd_cwnd << V_PARAM_SHIFT) - target_cwnd;
 
 		if (tcp_in_slow_start(tp)) {
-			/* Slow start.  */
+			/* Slow start. */
 			tcp_slow_start(tp, acked);
+			goto done;
+		}
+
+		/* Congestion avoidance. */
+		if (veno->diff < beta) {
+			/* In the "non-congestive state", increase cwnd
+			 * every rtt.
+			 */
+			tcp_cong_avoid_ai(tp, tp->snd_cwnd, 1);
 		} else {
-			/* Congestion avoidance. */
-			if (veno->diff < beta) {
-				/* In the "non-congestive state", increase cwnd
-				 *  every rtt.
-				 */
-				tcp_cong_avoid_ai(tp, tp->snd_cwnd, 1);
-			} else {
-				/* In the "congestive state", increase cwnd
-				 * every other rtt.
-				 */
-				if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
-					if (veno->inc &&
-					    tp->snd_cwnd < tp->snd_cwnd_clamp) {
-						tp->snd_cwnd++;
-						veno->inc = 0;
-					} else
-						veno->inc = 1;
-					tp->snd_cwnd_cnt = 0;
+			/* In the "congestive state", increase cwnd
+			 * every other rtt.
+			 */
+			if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
+				if (veno->inc &&
+				    tp->snd_cwnd < tp->snd_cwnd_clamp) {
+					tp->snd_cwnd++;
+					veno->inc = 0;
 				} else
-					tp->snd_cwnd_cnt++;
-			}
+					veno->inc = 1;
+				tp->snd_cwnd_cnt = 0;
+			} else
+				tp->snd_cwnd_cnt++;
 		}
+done:
 		if (tp->snd_cwnd < 2)
 			tp->snd_cwnd = 2;
 		else if (tp->snd_cwnd > tp->snd_cwnd_clamp)
-- 
1.8.3.1