4.19-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ 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 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: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/tcp_output.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2338,8 +2338,11 @@ static bool tcp_write_xmit(struct sock * } 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;