diff options
Diffstat (limited to 'net/ipv4/tcp_output.c')
-rw-r--r-- | net/ipv4/tcp_output.c | 45 |
1 files changed, 32 insertions, 13 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index d3b691f3a9e8..c31badfee806 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1904,7 +1904,9 @@ static int tso_fragment(struct sock *sk, enum tcp_queue tcp_queue, * This algorithm is from John Heffner. */ static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb, - bool *is_cwnd_limited, u32 max_segs) + bool *is_cwnd_limited, + bool *is_rwnd_limited, + u32 max_segs) { const struct inet_connection_sock *icsk = inet_csk(sk); u32 send_win, cong_win, limit, in_flight; @@ -1913,9 +1915,6 @@ static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb, int win_divisor; s64 delta; - if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) - goto send_now; - if (icsk->icsk_ca_state >= TCP_CA_Recovery) goto send_now; @@ -1981,10 +1980,27 @@ static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb, if ((s64)(delta - (u64)NSEC_PER_USEC * (tp->srtt_us >> 4)) < 0) goto send_now; - /* Ok, it looks like it is advisable to defer. */ + /* Ok, it looks like it is advisable to defer. + * Three cases are tracked : + * 1) We are cwnd-limited + * 2) We are rwnd-limited + * 3) We are application limited. + */ + if (cong_win < send_win) { + if (cong_win <= skb->len) { + *is_cwnd_limited = true; + return true; + } + } else { + if (send_win <= skb->len) { + *is_rwnd_limited = true; + return true; + } + } - if (cong_win < send_win && cong_win <= skb->len) - *is_cwnd_limited = true; + /* If this packet won't get more data, do not wait. */ + if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) + goto send_now; return true; @@ -2365,7 +2381,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, } else { if (!push_one && tcp_tso_should_defer(sk, skb, &is_cwnd_limited, - max_segs)) + &is_rwnd_limited, max_segs)) break; } @@ -2503,15 +2519,18 @@ void tcp_send_loss_probe(struct sock *sk) goto rearm_timer; } skb = skb_rb_last(&sk->tcp_rtx_queue); + if (unlikely(!skb)) { + WARN_ONCE(tp->packets_out, + "invalid inflight: %u state %u cwnd %u mss %d\n", + tp->packets_out, sk->sk_state, tp->snd_cwnd, mss); + inet_csk(sk)->icsk_pending = 0; + return; + } /* At most one outstanding TLP retransmission. */ if (tp->tlp_high_seq) goto rearm_timer; - /* Retransmit last segment. */ - if (WARN_ON(!skb)) - goto rearm_timer; - if (skb_still_in_host_queue(sk, skb)) goto rearm_timer; @@ -2929,7 +2948,7 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs) TCP_SKB_CB(skb)->sacked |= TCPCB_EVER_RETRANS; trace_tcp_retransmit_skb(sk, skb); } else if (err != -EBUSY) { - NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRETRANSFAIL); + NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPRETRANSFAIL, segs); } return err; } |