diff options
Diffstat (limited to 'net/ipv4/tcp.c')
| -rw-r--r-- | net/ipv4/tcp.c | 85 |
1 files changed, 65 insertions, 20 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index c4638e6f0238..97c8f5620c43 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -285,6 +285,8 @@ int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT; int sysctl_tcp_min_tso_segs __read_mostly = 2; +int sysctl_tcp_autocorking __read_mostly = 1; + struct percpu_counter tcp_orphan_count; EXPORT_SYMBOL_GPL(tcp_orphan_count); @@ -379,7 +381,7 @@ void tcp_init_sock(struct sock *sk) struct inet_connection_sock *icsk = inet_csk(sk); struct tcp_sock *tp = tcp_sk(sk); - skb_queue_head_init(&tp->out_of_order_queue); + __skb_queue_head_init(&tp->out_of_order_queue); tcp_init_xmit_timers(sk); tcp_prequeue_init(tp); INIT_LIST_HEAD(&tp->tsq_node); @@ -619,19 +621,58 @@ static inline void tcp_mark_urg(struct tcp_sock *tp, int flags) tp->snd_up = tp->write_seq; } -static inline void tcp_push(struct sock *sk, int flags, int mss_now, - int nonagle) +/* If a not yet filled skb is pushed, do not send it if + * we have data packets in Qdisc or NIC queues : + * Because TX completion will happen shortly, it gives a chance + * to coalesce future sendmsg() payload into this skb, without + * need for a timer, and with no latency trade off. + * As packets containing data payload have a bigger truesize + * than pure acks (dataless) packets, the last checks prevent + * autocorking if we only have an ACK in Qdisc/NIC queues, + * or if TX completion was delayed after we processed ACK packet. + */ +static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb, + int size_goal) { - if (tcp_send_head(sk)) { - struct tcp_sock *tp = tcp_sk(sk); + return skb->len < size_goal && + sysctl_tcp_autocorking && + skb != tcp_write_queue_head(sk) && + atomic_read(&sk->sk_wmem_alloc) > skb->truesize; +} + +static void tcp_push(struct sock *sk, int flags, int mss_now, + int nonagle, int size_goal) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *skb; - if (!(flags & MSG_MORE) || forced_push(tp)) - tcp_mark_push(tp, tcp_write_queue_tail(sk)); + if (!tcp_send_head(sk)) + return; + + skb = tcp_write_queue_tail(sk); + if (!(flags & MSG_MORE) || forced_push(tp)) + tcp_mark_push(tp, skb); + + tcp_mark_urg(tp, flags); + + if (tcp_should_autocork(sk, skb, size_goal)) { - tcp_mark_urg(tp, flags); - __tcp_push_pending_frames(sk, mss_now, - (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle); + /* avoid atomic op if TSQ_THROTTLED bit is already set */ + if (!test_bit(TSQ_THROTTLED, &tp->tsq_flags)) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING); + set_bit(TSQ_THROTTLED, &tp->tsq_flags); + } + /* It is possible TX completion already happened + * before we set TSQ_THROTTLED. + */ + if (atomic_read(&sk->sk_wmem_alloc) > skb->truesize) + return; } + + if (flags & MSG_MORE) + nonagle = TCP_NAGLE_CORK; + + __tcp_push_pending_frames(sk, mss_now, nonagle); } static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, @@ -934,7 +975,8 @@ new_segment: wait_for_sndbuf: set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); wait_for_memory: - tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); + tcp_push(sk, flags & ~MSG_MORE, mss_now, + TCP_NAGLE_PUSH, size_goal); if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) goto do_error; @@ -944,7 +986,7 @@ wait_for_memory: out: if (copied && !(flags & MSG_SENDPAGE_NOTLAST)) - tcp_push(sk, flags, mss_now, tp->nonagle); + tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); return copied; do_error: @@ -1002,7 +1044,8 @@ void tcp_free_fastopen_req(struct tcp_sock *tp) } } -static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, int *size) +static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, + int *copied, size_t size) { struct tcp_sock *tp = tcp_sk(sk); int err, flags; @@ -1017,11 +1060,12 @@ static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, int *size) if (unlikely(tp->fastopen_req == NULL)) return -ENOBUFS; tp->fastopen_req->data = msg; + tp->fastopen_req->size = size; flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0; err = __inet_stream_connect(sk->sk_socket, msg->msg_name, msg->msg_namelen, flags); - *size = tp->fastopen_req->copied; + *copied = tp->fastopen_req->copied; tcp_free_fastopen_req(tp); return err; } @@ -1041,7 +1085,7 @@ int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, flags = msg->msg_flags; if (flags & MSG_FASTOPEN) { - err = tcp_sendmsg_fastopen(sk, msg, &copied_syn); + err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size); if (err == -EINPROGRESS && copied_syn > 0) goto out; else if (err) @@ -1225,7 +1269,8 @@ wait_for_sndbuf: set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); wait_for_memory: if (copied) - tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); + tcp_push(sk, flags & ~MSG_MORE, mss_now, + TCP_NAGLE_PUSH, size_goal); if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) goto do_error; @@ -1236,7 +1281,7 @@ wait_for_memory: out: if (copied) - tcp_push(sk, flags, mss_now, tp->nonagle); + tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); release_sock(sk); return copied + copied_syn; @@ -1623,11 +1668,11 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) && !sysctl_tcp_low_latency && net_dma_find_channel()) { - preempt_enable_no_resched(); + preempt_enable(); tp->ucopy.pinned_list = dma_pin_iovec_pages(msg->msg_iov, len); } else { - preempt_enable_no_resched(); + preempt_enable(); } } #endif @@ -2186,7 +2231,7 @@ adjudge_to_death: /* This is a (useful) BSD violating of the RFC. There is a * problem with TCP as specified in that the other end could * keep a socket open forever with no application left this end. - * We use a 3 minute timeout (about the same as BSD) then kill + * We use a 1 minute timeout (about the same as BSD) then kill * our end. If they send after that then tough - BUT: long enough * that we won't make the old 4*rto = almost no time - whoops * reset mistake. |