Patchwork [net-next,10/15] tcp: remove tp->lost_out guard to make joining diff nicer

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Submitter Ilpo Järvinen
Date Sept. 20, 2008, 5:52 p.m.
Message ID <1221933153-11874-11-git-send-email-ilpo.jarvinen@helsinki.fi>
Download mbox | patch
Permalink /patch/733/
State Rejected
Headers show

Comments

Ilpo Järvinen - Sept. 20, 2008, 5:52 p.m.
The validity of the retransmit_high must then be ensured
if no L'ed skb exits!

This makes only minor change to behavior, we now have to
iterate the head to find out that the loop terminates.
And it's anyway quite unlikely scenario to have
!tp->lost_out in here...

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
---
 net/ipv4/tcp_output.c |   75 +++++++++++++++++++++++++------------------------
 1 files changed, 38 insertions(+), 37 deletions(-)

Patch

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index d5f53f8..fc7bfd6 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2036,53 +2036,54 @@  void tcp_xmit_retransmit_queue(struct sock *sk)
 	struct sk_buff *skb;
 	int mib_idx;
 
+	if (!tp->lost_out)
+		tp->retransmit_high = tp->snd_una;
+
 	if (tp->retransmit_skb_hint)
 		skb = tp->retransmit_skb_hint;
 	else
 		skb = tcp_write_queue_head(sk);
 
 	/* First pass: retransmit lost packets. */
-	if (tp->lost_out) {
-		tcp_for_write_queue_from(skb, sk) {
-			__u8 sacked = TCP_SKB_CB(skb)->sacked;
+	tcp_for_write_queue_from(skb, sk) {
+		__u8 sacked = TCP_SKB_CB(skb)->sacked;
 
-			if (skb == tcp_send_head(sk))
-				break;
-			/* we could do better than to assign each time */
-			tp->retransmit_skb_hint = skb;
-
-			/* Assume this retransmit will generate
-			 * only one packet for congestion window
-			 * calculation purposes.  This works because
-			 * tcp_retransmit_skb() will chop up the
-			 * packet to be MSS sized and all the
-			 * packet counting works out.
-			 */
-			if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)
-				return;
-			if (!before(TCP_SKB_CB(skb)->seq, tp->retransmit_high))
-				break;
-			if (sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))
-				continue;
+		if (skb == tcp_send_head(sk))
+			break;
+		/* we could do better than to assign each time */
+		tp->retransmit_skb_hint = skb;
+
+		/* Assume this retransmit will generate
+		 * only one packet for congestion window
+		 * calculation purposes.  This works because
+		 * tcp_retransmit_skb() will chop up the
+		 * packet to be MSS sized and all the
+		 * packet counting works out.
+		 */
+		if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)
+			return;
+		if (!before(TCP_SKB_CB(skb)->seq, tp->retransmit_high))
+			break;
+		if (sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))
+			continue;
 
-			if (!(sacked & TCPCB_LOST))
-				continue;
+		if (!(sacked & TCPCB_LOST))
+			continue;
 
-			if (tcp_retransmit_skb(sk, skb)) {
-				tp->retransmit_skb_hint = NULL;
-				return;
-			}
-			if (icsk->icsk_ca_state != TCP_CA_Loss)
-				mib_idx = LINUX_MIB_TCPFASTRETRANS;
-			else
-				mib_idx = LINUX_MIB_TCPSLOWSTARTRETRANS;
-			NET_INC_STATS_BH(sock_net(sk), mib_idx);
-
-			if (skb == tcp_write_queue_head(sk))
-				inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
-							  inet_csk(sk)->icsk_rto,
-							  TCP_RTO_MAX);
+		if (tcp_retransmit_skb(sk, skb)) {
+			tp->retransmit_skb_hint = NULL;
+			return;
 		}
+		if (icsk->icsk_ca_state != TCP_CA_Loss)
+			mib_idx = LINUX_MIB_TCPFASTRETRANS;
+		else
+			mib_idx = LINUX_MIB_TCPSLOWSTARTRETRANS;
+		NET_INC_STATS_BH(sock_net(sk), mib_idx);
+
+		if (skb == tcp_write_queue_head(sk))
+			inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+						  inet_csk(sk)->icsk_rto,
+						  TCP_RTO_MAX);
 	}
 
 	/* OK, demanded retransmission is finished. */