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authorIlpo Järvinen <ilpo.jarvinen@helsinki.fi>2008-09-20 21:24:21 -0700
committerDavid S. Miller <davem@davemloft.net>2008-09-20 21:24:21 -0700
commit0e1c54c2a405494281e0639aacc90db03b50ae77 (patch)
treeba5098bdf80603d4b5aa74af11738620f2ea7681
parent08ebd1721ab8fd362e90ae17b461c07b23fa2824 (diff)
tcp: reorganize retransmit code loops
Both loops are quite similar, so they can be combined with little effort. As a result, forward_skb_hint becomes obsolete as well. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/tcp.h1
-rw-r--r--include/net/tcp.h1
-rw-r--r--net/ipv4/tcp_output.c79
3 files changed, 33 insertions, 48 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index d7637c4b284..76729062829 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -342,7 +342,6 @@ struct tcp_sock {
struct sk_buff* lost_skb_hint;
struct sk_buff *scoreboard_skb_hint;
struct sk_buff *retransmit_skb_hint;
- struct sk_buff *forward_skb_hint;
struct sk_buff_head out_of_order_queue; /* Out of order segments go here */
diff --git a/include/net/tcp.h b/include/net/tcp.h
index d0e90c50722..220f54cf42e 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1042,7 +1042,6 @@ static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp)
tp->lost_skb_hint = NULL;
tp->scoreboard_skb_hint = NULL;
tp->retransmit_skb_hint = NULL;
- tp->forward_skb_hint = NULL;
}
/* MD5 Signature */
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 9f44be633ef..b5b4ddcdda4 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2032,7 +2032,9 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
const struct inet_connection_sock *icsk = inet_csk(sk);
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb;
+ struct sk_buff *hole = NULL;
int mib_idx;
+ int fwd_rexmitting = 0;
if (!tp->lost_out)
tp->retransmit_high = tp->snd_una;
@@ -2049,7 +2051,8 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
if (skb == tcp_send_head(sk))
break;
/* we could do better than to assign each time */
- tp->retransmit_skb_hint = skb;
+ if (hole == NULL)
+ tp->retransmit_skb_hint = skb;
/* Assume this retransmit will generate
* only one packet for congestion window
@@ -2060,65 +2063,49 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
*/
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 (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. */
- if (!tcp_can_forward_retransmit(sk))
- return;
- if (tp->forward_skb_hint)
- skb = tp->forward_skb_hint;
- else
- skb = tcp_write_queue_head(sk);
+ if (fwd_rexmitting) {
+begin_fwd:
+ if (!before(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp)))
+ break;
+ mib_idx = LINUX_MIB_TCPFORWARDRETRANS;
- tcp_for_write_queue_from(skb, sk) {
- if (skb == tcp_send_head(sk))
- break;
- tp->forward_skb_hint = skb;
+ } else if (!before(TCP_SKB_CB(skb)->seq, tp->retransmit_high)) {
+ if (!tcp_can_forward_retransmit(sk))
+ break;
+ /* Backtrack if necessary to non-L'ed skb */
+ if (hole != NULL) {
+ skb = hole;
+ hole = NULL;
+ }
+ fwd_rexmitting = 1;
+ goto begin_fwd;
- if (!before(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp)))
- break;
+ } else if (!(sacked & TCPCB_LOST)) {
+ if (hole == NULL && !(sacked & TCPCB_SACKED_RETRANS))
+ hole = skb;
+ continue;
- if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)
- break;
+ } else {
+ if (icsk->icsk_ca_state != TCP_CA_Loss)
+ mib_idx = LINUX_MIB_TCPFASTRETRANS;
+ else
+ mib_idx = LINUX_MIB_TCPSLOWSTARTRETRANS;
+ }
- if (TCP_SKB_CB(skb)->sacked & TCPCB_TAGBITS)
+ if (sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))
continue;
- /* Ok, retransmit it. */
if (tcp_retransmit_skb(sk, skb)) {
- tp->forward_skb_hint = NULL;
- break;
+ tp->retransmit_skb_hint = NULL;
+ return;
}
+ 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);
-
- NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFORWARDRETRANS);
}
}