diff options
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 89 |
1 files changed, 78 insertions, 11 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index b5521a9..e08245b 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -71,6 +71,7 @@ #include <net/inet_common.h> #include <linux/ipsec.h> #include <asm/unaligned.h> +#include <net/netdma.h> int sysctl_tcp_timestamps = 1; int sysctl_tcp_window_scaling = 1; @@ -1688,17 +1689,26 @@ static inline void tcp_moderate_cwnd(struct tcp_sock *tp) tp->snd_cwnd_stamp = tcp_time_stamp; } +/* Lower bound on congestion window is slow start threshold + * unless congestion avoidance choice decides to overide it. + */ +static inline u32 tcp_cwnd_min(const struct sock *sk) +{ + const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; + + return ca_ops->min_cwnd ? ca_ops->min_cwnd(sk) : tcp_sk(sk)->snd_ssthresh; +} + /* Decrease cwnd each second ack. */ static void tcp_cwnd_down(struct sock *sk) { - const struct inet_connection_sock *icsk = inet_csk(sk); struct tcp_sock *tp = tcp_sk(sk); int decr = tp->snd_cwnd_cnt + 1; tp->snd_cwnd_cnt = decr&1; decr >>= 1; - if (decr && tp->snd_cwnd > icsk->icsk_ca_ops->min_cwnd(sk)) + if (decr && tp->snd_cwnd > tcp_cwnd_min(sk)) tp->snd_cwnd -= decr; tp->snd_cwnd = min(tp->snd_cwnd, tcp_packets_in_flight(tp)+1); @@ -3785,6 +3795,50 @@ static inline int tcp_checksum_complete_user(struct sock *sk, struct sk_buff *sk __tcp_checksum_complete_user(sk, skb); } +#ifdef CONFIG_NET_DMA +static int tcp_dma_try_early_copy(struct sock *sk, struct sk_buff *skb, int hlen) +{ + struct tcp_sock *tp = tcp_sk(sk); + int chunk = skb->len - hlen; + int dma_cookie; + int copied_early = 0; + + if (tp->ucopy.wakeup) + return 0; + + if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) + tp->ucopy.dma_chan = get_softnet_dma(); + + if (tp->ucopy.dma_chan && skb->ip_summed == CHECKSUM_UNNECESSARY) { + + dma_cookie = dma_skb_copy_datagram_iovec(tp->ucopy.dma_chan, + skb, hlen, tp->ucopy.iov, chunk, tp->ucopy.pinned_list); + + if (dma_cookie < 0) + goto out; + + tp->ucopy.dma_cookie = dma_cookie; + copied_early = 1; + + tp->ucopy.len -= chunk; + tp->copied_seq += chunk; + tcp_rcv_space_adjust(sk); + + if ((tp->ucopy.len == 0) || + (tcp_flag_word(skb->h.th) & TCP_FLAG_PSH) || + (atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1))) { + tp->ucopy.wakeup = 1; + sk->sk_data_ready(sk, 0); + } + } else if (chunk > 0) { + tp->ucopy.wakeup = 1; + sk->sk_data_ready(sk, 0); + } +out: + return copied_early; +} +#endif /* CONFIG_NET_DMA */ + /* * TCP receive function for the ESTABLISHED state. * @@ -3886,8 +3940,6 @@ int tcp_rcv_established(struct sock *sk, struct sk_buff *skb, tp->rcv_nxt == tp->rcv_wup) tcp_store_ts_recent(tp); - tcp_rcv_rtt_measure_ts(sk, skb); - /* We know that such packets are checksummed * on entry. */ @@ -3901,14 +3953,23 @@ int tcp_rcv_established(struct sock *sk, struct sk_buff *skb, } } else { int eaten = 0; + int copied_early = 0; - if (tp->ucopy.task == current && - tp->copied_seq == tp->rcv_nxt && - len - tcp_header_len <= tp->ucopy.len && - sock_owned_by_user(sk)) { - __set_current_state(TASK_RUNNING); + if (tp->copied_seq == tp->rcv_nxt && + len - tcp_header_len <= tp->ucopy.len) { +#ifdef CONFIG_NET_DMA + if (tcp_dma_try_early_copy(sk, skb, tcp_header_len)) { + copied_early = 1; + eaten = 1; + } +#endif + if (tp->ucopy.task == current && sock_owned_by_user(sk) && !copied_early) { + __set_current_state(TASK_RUNNING); - if (!tcp_copy_to_iovec(sk, skb, tcp_header_len)) { + if (!tcp_copy_to_iovec(sk, skb, tcp_header_len)) + eaten = 1; + } + if (eaten) { /* Predicted packet is in window by definition. * seq == rcv_nxt and rcv_wup <= rcv_nxt. * Hence, check seq<=rcv_wup reduces to: @@ -3924,8 +3985,9 @@ int tcp_rcv_established(struct sock *sk, struct sk_buff *skb, __skb_pull(skb, tcp_header_len); tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq; NET_INC_STATS_BH(LINUX_MIB_TCPHPHITSTOUSER); - eaten = 1; } + if (copied_early) + tcp_cleanup_rbuf(sk, skb->len); } if (!eaten) { if (tcp_checksum_complete_user(sk, skb)) @@ -3966,6 +4028,11 @@ int tcp_rcv_established(struct sock *sk, struct sk_buff *skb, __tcp_ack_snd_check(sk, 0); no_ack: +#ifdef CONFIG_NET_DMA + if (copied_early) + __skb_queue_tail(&sk->sk_async_wait_queue, skb); + else +#endif if (eaten) __kfree_skb(skb); else |
