diff options
Diffstat (limited to 'net/ipv4/tcp_output.c')
| -rw-r--r-- | net/ipv4/tcp_output.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index a3d453b94747..eb73a1dccf56 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -333,10 +333,19 @@ static void tcp_ecn_send_synack(struct sock *sk, struct sk_buff *skb) static void tcp_ecn_send_syn(struct sock *sk, struct sk_buff *skb) { struct tcp_sock *tp = tcp_sk(sk); + bool use_ecn = sock_net(sk)->ipv4.sysctl_tcp_ecn == 1 || + tcp_ca_needs_ecn(sk); + + if (!use_ecn) { + const struct dst_entry *dst = __sk_dst_get(sk); + + if (dst && dst_feature(dst, RTAX_FEATURE_ECN)) + use_ecn = true; + } tp->ecn_flags = 0; - if (sock_net(sk)->ipv4.sysctl_tcp_ecn == 1 || - tcp_ca_needs_ecn(sk)) { + + if (use_ecn) { TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_ECE | TCPHDR_CWR; tp->ecn_flags = TCP_ECN_OK; if (tcp_ca_needs_ecn(sk)) @@ -1553,7 +1562,7 @@ static unsigned int tcp_mss_split_point(const struct sock *sk, static inline unsigned int tcp_cwnd_test(const struct tcp_sock *tp, const struct sk_buff *skb) { - u32 in_flight, cwnd; + u32 in_flight, cwnd, halfcwnd; /* Don't be strict about the congestion window for the final FIN. */ if ((TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) && @@ -1562,10 +1571,14 @@ static inline unsigned int tcp_cwnd_test(const struct tcp_sock *tp, in_flight = tcp_packets_in_flight(tp); cwnd = tp->snd_cwnd; - if (in_flight < cwnd) - return (cwnd - in_flight); + if (in_flight >= cwnd) + return 0; - return 0; + /* For better scheduling, ensure we have at least + * 2 GSO packets in flight. + */ + halfcwnd = max(cwnd >> 1, 1U); + return min(halfcwnd, cwnd - in_flight); } /* Initialize TSO state of a skb. |