tcp: use TCP_DEFAULT_INIT_RCVWND in tcp_fixup_rcvbuf() (e9266a02) · Commits · 戴 / test

Since commit (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 limited default window to maximum of 10*1460 and 2*MSS, we use same heuristic in this patch. Signed-off-by:

Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/ipv4/tcp_input.c

+15 −8

Original line number	Diff line number	Diff line
		@@ -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

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