diff options
| -rw-r--r-- | net/ipv4/tcp_input.c | 38 |
1 files changed, 30 insertions, 8 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index bef2c8b64d83..501d8d4d4ba4 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -454,11 +454,12 @@ static void tcp_sndbuf_expand(struct sock *sk) */ /* Slow part of check#2. */ -static int __tcp_grow_window(const struct sock *sk, const struct sk_buff *skb) +static int __tcp_grow_window(const struct sock *sk, const struct sk_buff *skb, + unsigned int skbtruesize) { struct tcp_sock *tp = tcp_sk(sk); /* Optimize this! */ - int truesize = tcp_win_from_space(sk, skb->truesize) >> 1; + int truesize = tcp_win_from_space(sk, skbtruesize) >> 1; int window = tcp_win_from_space(sk, sock_net(sk)->ipv4.sysctl_tcp_rmem[2]) >> 1; while (tp->rcv_ssthresh <= window) { @@ -471,7 +472,27 @@ static int __tcp_grow_window(const struct sock *sk, const struct sk_buff *skb) return 0; } -static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb) +/* Even if skb appears to have a bad len/truesize ratio, TCP coalescing + * can play nice with us, as sk_buff and skb->head might be either + * freed or shared with up to MAX_SKB_FRAGS segments. + * Only give a boost to drivers using page frag(s) to hold the frame(s), + * and if no payload was pulled in skb->head before reaching us. + */ +static u32 truesize_adjust(bool adjust, const struct sk_buff *skb) +{ + u32 truesize = skb->truesize; + + if (adjust && !skb_headlen(skb)) { + truesize -= SKB_TRUESIZE(skb_end_offset(skb)); + /* paranoid check, some drivers might be buggy */ + if (unlikely((int)truesize < (int)skb->len)) + truesize = skb->truesize; + } + return truesize; +} + +static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb, + bool adjust) { struct tcp_sock *tp = tcp_sk(sk); int room; @@ -480,15 +501,16 @@ static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb) /* Check #1 */ if (room > 0 && !tcp_under_memory_pressure(sk)) { + unsigned int truesize = truesize_adjust(adjust, skb); int incr; /* Check #2. Increase window, if skb with such overhead * will fit to rcvbuf in future. */ - if (tcp_win_from_space(sk, skb->truesize) <= skb->len) + if (tcp_win_from_space(sk, truesize) <= skb->len) incr = 2 * tp->advmss; else - incr = __tcp_grow_window(sk, skb); + incr = __tcp_grow_window(sk, skb, truesize); if (incr) { incr = max_t(int, incr, 2 * skb->len); @@ -782,7 +804,7 @@ static void tcp_event_data_recv(struct sock *sk, struct sk_buff *skb) tcp_ecn_check_ce(sk, skb); if (skb->len >= 128) - tcp_grow_window(sk, skb); + tcp_grow_window(sk, skb, true); } /* Called to compute a smoothed rtt estimate. The data fed to this @@ -4769,7 +4791,7 @@ coalesce_done: * and trigger fast retransmit. */ if (tcp_is_sack(tp)) - tcp_grow_window(sk, skb); + tcp_grow_window(sk, skb, true); kfree_skb_partial(skb, fragstolen); skb = NULL; goto add_sack; @@ -4857,7 +4879,7 @@ end: * and trigger fast retransmit. */ if (tcp_is_sack(tp)) - tcp_grow_window(sk, skb); + tcp_grow_window(sk, skb, false); skb_condense(skb); skb_set_owner_r(skb, sk); } |