On Wed, Dec 5, 2018 at 2:28 PM Soheil Hassas Yeganeh <soh...@google.com> wrote:
>
> On Wed, Dec 5, 2018 at 5:24 PM Eric Dumazet <eduma...@google.com> wrote:
> >
> > 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 <eduma...@google.com>
>
> Acked-by: Soheil Hassas Yeganeh <soh...@google.com>
Reviewed-by: Yuchung Cheng <ych...@google.com>
>
> Excellent catch! Thank you for the fix, Eric!
>
> > ---
> > 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
> > 68b5326f73212ffe7111dd0f91e0a1246fb0ae25..3186902347584090256467d8679320666aa0257e
> > 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;
> > --
> > 2.20.0.rc2.403.gdbc3b29805-goog
> >
