From: Eric Dumazet <edumazet@google.com>
Date: Wed, 5 Dec 2018 14:24:31 -0800
Subject: tcp: Do not underestimate rwnd_limited
Git-commit: 41727549de3e7281feb174d568c6e46823db8684
Patch-mainline: v4.20-rc6
References: networking-stable-18_12_12
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 <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
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 68b5326f7321..318690234758 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2356,8 +2356,11 @@ 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;
--
2.20.1