From 03b271cb9175b8fc9d6dfcfb3e87f23a7d6815dc Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 5 Dec 2018 14:24:31 -0800 Subject: [PATCH] tcp: Do not underestimate rwnd_limited [ Upstream commit 41727549de3e7281feb174d568c6e46823db8684 ] If available rwnd is too small, tcp_tso_should_defer() can decide it is worth waiting before splitting a TSO packet. This really means we are rwnd limited. Fixes: 5615f88614a4 ("tcp: instrument how long TCP is limited by receive window") Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Reviewed-by: Yuchung Cheng Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_output.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 68f65ddf9e3c..97e8aea4ac71 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2338,8 +2338,11 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, } else { if (!push_one && tcp_tso_should_defer(sk, skb, &is_cwnd_limited, - max_segs)) + max_segs)) { + if (!is_cwnd_limited) + is_rwnd_limited = true; break; + } } limit = mss_now; -- 2.17.1