tcp: Add snd_wnd to TCP_INFO
authorThomas Higdon <tph@fb.com>
Fri, 13 Sep 2019 23:23:35 +0000 (23:23 +0000)
committerDavid S. Miller <davem@davemloft.net>
Mon, 16 Sep 2019 14:26:11 +0000 (16:26 +0200)
commit8f7baad7f03543451af27f5380fc816b008aa1f2
tree6bf8b48edf5926cfb1b372f611d41fffe872d237
parentf9af2dbbfe01def62765a58af7fbc488351893c3
tcp: Add snd_wnd to TCP_INFO

Neal Cardwell mentioned that snd_wnd would be useful for diagnosing TCP
performance problems --
> (1) Usually when we're diagnosing TCP performance problems, we do so
> from the sender, since the sender makes most of the
> performance-critical decisions (cwnd, pacing, TSO size, TSQ, etc).
> From the sender-side the thing that would be most useful is to see
> tp->snd_wnd, the receive window that the receiver has advertised to
> the sender.

This serves the purpose of adding an additional __u32 to avoid the
would-be hole caused by the addition of the tcpi_rcvi_ooopack field.

Signed-off-by: Thomas Higdon <tph@fb.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/uapi/linux/tcp.h
net/ipv4/tcp.c