netdev - [PATCH v2 1/1] tcp: fixing TLP's FIN recovery

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Date:	Thu, 12 Jun 2014 17:08:32 +0200
From:	Per Hurtig <per.hurtig@....se>
To:	eric.dumazet@...il.com
Cc:	Per Hurtig <per.hurtig@....se>, panweiping3@...il.com,
	nanditad@...gle.com, netdev@...r.kernel.org, anna.brunstrom@....se,
	mohammad.rajiullah@....se, ncardwell@...gle.com,
	sergei.shtylyov@...entembedded.com
Subject: [PATCH v2 1/1] tcp: fixing TLP's FIN recovery

Fix to a problem observed when losing a FIN segment that does not
contain data.  In such situations, TLP is unable to recover from
*any* tail loss and instead adds at least PTO ms to the
retransmission process, i.e., RTO = RTO + PTO.

Signed-off-by: Per Hurtig <per.hurtig@....se>
---
 net/ipv4/tcp_output.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index ad7549f..819bf0c 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2131,9 +2131,7 @@ void tcp_send_loss_probe(struct sock *sk)
 	if (WARN_ON(!skb || !tcp_skb_pcount(skb)))
 		goto rearm_timer;
 
-	/* Probe with zero data doesn't trigger fast recovery. */
-	if (skb->len > 0)
-		err = __tcp_retransmit_skb(sk, skb);
+	err = __tcp_retransmit_skb(sk, skb);
 
 	/* Record snd_nxt for loss detection. */
 	if (likely(!err))
-- 
1.9.1


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