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Commit 0e1c54c2 authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by David S. Miller
Browse files

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: default avatarIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 08ebd172

include/linux/tcp.h

+0 −1
Original line number Original line Diff line number Diff line
@@ -342,7 +342,6 @@ struct tcp_sock { 
	struct sk_buff* lost_skb_hint;

	struct sk_buff* lost_skb_hint;

	struct sk_buff *scoreboard_skb_hint;

	struct sk_buff *scoreboard_skb_hint;

	struct sk_buff *retransmit_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 */

	struct sk_buff_head	out_of_order_queue; /* Out of order segments go here */

include/net/tcp.h

+0 −1
Original line number Original line Diff line number Diff line
@@ -1042,7 +1042,6 @@ static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) 
	tp->lost_skb_hint = NULL;

	tp->lost_skb_hint = NULL;

	tp->scoreboard_skb_hint = NULL;

	tp->scoreboard_skb_hint = NULL;

	tp->retransmit_skb_hint = NULL;

	tp->retransmit_skb_hint = NULL;

	tp->forward_skb_hint = NULL;

}

}





/* MD5 Signature */

/* MD5 Signature */

net/ipv4/tcp_output.c

+33 −46
Original line number Original line Diff line number Diff line
@@ -2032,7 +2032,9 @@ void tcp_xmit_retransmit_queue(struct sock *sk) 
	const struct inet_connection_sock *icsk = inet_csk(sk);

	const struct inet_connection_sock *icsk = inet_csk(sk);

	struct tcp_sock *tp = tcp_sk(sk);

	struct tcp_sock *tp = tcp_sk(sk);

	struct sk_buff *skb;

	struct sk_buff *skb;

	struct sk_buff *hole = NULL;

	int mib_idx;

	int mib_idx;

	int fwd_rexmitting = 0;





	if (!tp->lost_out)

	if (!tp->lost_out)

		tp->retransmit_high = tp->snd_una;

		tp->retransmit_high = tp->snd_una;
@@ -2049,6 +2051,7 @@ void tcp_xmit_retransmit_queue(struct sock *sk) 
		if (skb == tcp_send_head(sk))

		if (skb == tcp_send_head(sk))

			break;

			break;

		/* we could do better than to assign each time */

		/* we could do better than to assign each time */

		if (hole == NULL)

			tp->retransmit_skb_hint = skb;

			tp->retransmit_skb_hint = skb;





		/* Assume this retransmit will generate

		/* Assume this retransmit will generate
@@ -2060,65 +2063,49 @@ void tcp_xmit_retransmit_queue(struct sock *sk) 
		 */

		 */

		if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)

		if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)

			return;

			return;

		if (!before(TCP_SKB_CB(skb)->seq, tp->retransmit_high))



		if (fwd_rexmitting) {

begin_fwd:

			if (!before(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp)))

				break;

				break;

		if (sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))

			mib_idx = LINUX_MIB_TCPFORWARDRETRANS;

			continue;





		if (!(sacked & TCPCB_LOST))

		} 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;



		} else if (!(sacked & TCPCB_LOST)) {

			if (hole == NULL && !(sacked & TCPCB_SACKED_RETRANS))

				hole = skb;

			continue;

			continue;





		if (tcp_retransmit_skb(sk, skb)) {

		} else {

			tp->retransmit_skb_hint = NULL;

			return;

		}

			if (icsk->icsk_ca_state != TCP_CA_Loss)

			if (icsk->icsk_ca_state != TCP_CA_Loss)

				mib_idx = LINUX_MIB_TCPFASTRETRANS;

				mib_idx = LINUX_MIB_TCPFASTRETRANS;

			else

			else

				mib_idx = LINUX_MIB_TCPSLOWSTARTRETRANS;

				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 (sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))

	if (!tcp_can_forward_retransmit(sk))

		return;



	if (tp->forward_skb_hint)

		skb = tp->forward_skb_hint;

	else

		skb = tcp_write_queue_head(sk);



	tcp_for_write_queue_from(skb, sk) {

		if (skb == tcp_send_head(sk))

			break;

		tp->forward_skb_hint = skb;



		if (!before(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp)))

			break;



		if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)

			break;



		if (TCP_SKB_CB(skb)->sacked & TCPCB_TAGBITS)

			continue;

			continue;





		/* Ok, retransmit it. */

		if (tcp_retransmit_skb(sk, skb)) {

		if (tcp_retransmit_skb(sk, skb)) {

			tp->forward_skb_hint = NULL;

			tp->retransmit_skb_hint = NULL;

			break;

			return;

		}

		}

		NET_INC_STATS_BH(sock_net(sk), mib_idx);





		if (skb == tcp_write_queue_head(sk))

		if (skb == tcp_write_queue_head(sk))

			inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,

			inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,

						  inet_csk(sk)->icsk_rto,

						  inet_csk(sk)->icsk_rto,

						  TCP_RTO_MAX);

						  TCP_RTO_MAX);



		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFORWARDRETRANS);

	}

	}

}

}