From e9266a02b7e6542355431955075b4e688962fc0a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 20 Oct 2011 16:53:56 -0400 Subject: tcp: use TCP_DEFAULT_INIT_RCVWND in tcp_fixup_rcvbuf() Since commit 356f039822b (TCP: increase default initial receive window.), we allow sender to send 10 (TCP_DEFAULT_INIT_RCVWND) segments. Change tcp_fixup_rcvbuf() to reflect this change, even if no real change is expected, since sysctl_tcp_rmem[1] = 87380 and this value is bigger than tcp_fixup_rcvbuf() computed rcvmem (~23720) Note: Since commit 356f039822b limited default window to maximum of 10*1460 and 2*MSS, we use same heuristic in this patch. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) (limited to 'net') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 1e848b26c2b9..e8e6d492f328 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -345,17 +345,24 @@ static void tcp_grow_window(struct sock *sk, struct sk_buff *skb) static void tcp_fixup_rcvbuf(struct sock *sk) { - struct tcp_sock *tp = tcp_sk(sk); - int rcvmem = SKB_TRUESIZE(tp->advmss + MAX_TCP_HEADER); + u32 mss = tcp_sk(sk)->advmss; + u32 icwnd = TCP_DEFAULT_INIT_RCVWND; + int rcvmem; - /* Try to select rcvbuf so that 4 mss-sized segments - * will fit to window and corresponding skbs will fit to our rcvbuf. - * (was 3; 4 is minimum to allow fast retransmit to work.) + /* Limit to 10 segments if mss <= 1460, + * or 14600/mss segments, with a minimum of two segments. */ - while (tcp_win_from_space(rcvmem) < tp->advmss) + if (mss > 1460) + icwnd = max_t(u32, (1460 * TCP_DEFAULT_INIT_RCVWND) / mss, 2); + + rcvmem = SKB_TRUESIZE(mss + MAX_TCP_HEADER); + while (tcp_win_from_space(rcvmem) < mss) rcvmem += 128; - if (sk->sk_rcvbuf < 4 * rcvmem) - sk->sk_rcvbuf = min(4 * rcvmem, sysctl_tcp_rmem[2]); + + rcvmem *= icwnd; + + if (sk->sk_rcvbuf < rcvmem) + sk->sk_rcvbuf = min(rcvmem, sysctl_tcp_rmem[2]); } /* 4. Try to fixup all. It is made immediately after connection enters -- cgit v1.2.3