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tcp: early retransmit: tcp_enter_recovery()

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This a prepartion patch that refactors the code to enter recovery
into a new function tcp_enter_recovery(). It's needed to implement
the delayed fast retransmit in ER.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Yuchung Cheng 2012-05-02 13:30:02 +00:00 committed by David S. Miller
parent 5c6239c8f8
commit 1fbc340514
1 changed files with 34 additions and 27 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

61
net/ipv4/tcp_input.c
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@ -3022,6 +3022,38 @@ static void tcp_update_cwnd_in_recovery(struct sock *sk, int newly_acked_sacked,
tp->snd_cwnd = tcp_packets_in_flight(tp) + sndcnt;
}
static void tcp_enter_recovery(struct sock *sk, bool ece_ack)
{
struct tcp_sock *tp = tcp_sk(sk);
int mib_idx;
if (tcp_is_reno(tp))
mib_idx = LINUX_MIB_TCPRENORECOVERY;
else
mib_idx = LINUX_MIB_TCPSACKRECOVERY;
NET_INC_STATS_BH(sock_net(sk), mib_idx);
tp->high_seq = tp->snd_nxt;
tp->prior_ssthresh = 0;
tp->undo_marker = tp->snd_una;
tp->undo_retrans = tp->retrans_out;
if (inet_csk(sk)->icsk_ca_state < TCP_CA_CWR) {
if (!ece_ack)
tp->prior_ssthresh = tcp_current_ssthresh(sk);
tp->snd_ssthresh = inet_csk(sk)->icsk_ca_ops->ssthresh(sk);
TCP_ECN_queue_cwr(tp);
}
tp->bytes_acked = 0;
tp->snd_cwnd_cnt = 0;
tp->prior_cwnd = tp->snd_cwnd;
tp->prr_delivered = 0;
tp->prr_out = 0;
tcp_set_ca_state(sk, TCP_CA_Recovery);
}
/* Process an event, which can update packets-in-flight not trivially.
* Main goal of this function is to calculate new estimate for left_out,
* taking into account both packets sitting in receiver's buffer and
@ -3041,7 +3073,7 @@ static void tcp_fastretrans_alert(struct sock *sk, int pkts_acked,
struct tcp_sock *tp = tcp_sk(sk);
int do_lost = is_dupack || ((flag & FLAG_DATA_SACKED) &&
(tcp_fackets_out(tp) > tp->reordering));
int fast_rexmit = 0, mib_idx;
int fast_rexmit = 0;
if (WARN_ON(!tp->packets_out && tp->sacked_out))
tp->sacked_out = 0;
@ -3142,32 +3174,7 @@ static void tcp_fastretrans_alert(struct sock *sk, int pkts_acked,
}
/* Otherwise enter Recovery state */
if (tcp_is_reno(tp))
mib_idx = LINUX_MIB_TCPRENORECOVERY;
else
mib_idx = LINUX_MIB_TCPSACKRECOVERY;
NET_INC_STATS_BH(sock_net(sk), mib_idx);
tp->high_seq = tp->snd_nxt;
tp->prior_ssthresh = 0;
tp->undo_marker = tp->snd_una;
tp->undo_retrans = tp->retrans_out;
if (icsk->icsk_ca_state < TCP_CA_CWR) {
if (!(flag & FLAG_ECE))
tp->prior_ssthresh = tcp_current_ssthresh(sk);
tp->snd_ssthresh = icsk->icsk_ca_ops->ssthresh(sk);
TCP_ECN_queue_cwr(tp);
}
tp->bytes_acked = 0;
tp->snd_cwnd_cnt = 0;
tp->prior_cwnd = tp->snd_cwnd;
tp->prr_delivered = 0;
tp->prr_out = 0;
tcp_set_ca_state(sk, TCP_CA_Recovery);
tcp_enter_recovery(sk, (flag & FLAG_ECE));
fast_rexmit = 1;
}