From: Neal Cardwell <ncardwell@google.com>
To: Thomas Higdon <tph@fb.com>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
Jonathan Lemon <jonathan.lemon@gmail.com>,
Dave Jones <dsj@fb.com>, Eric Dumazet <edumazet@google.com>,
Dave Taht <dave.taht@gmail.com>,
Yuchung Cheng <ycheng@google.com>,
Soheil Hassas Yeganeh <soheil@google.com>
Subject: Re: [PATCH v5 2/2] tcp: Add snd_wnd to TCP_INFO
Date: Sat, 14 Sep 2019 11:45:05 -0400 [thread overview]
Message-ID: <CADVnQykBFBU5bFLXRr_aRzxNVpNGQRtELG5kd6viGWqO0uyyng@mail.gmail.com> (raw)
In-Reply-To: <20190913232332.44036-2-tph@fb.com>
On Fri, Sep 13, 2019 at 7:23 PM Thomas Higdon <tph@fb.com> wrote:
>
> 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>
> ---
> changes since v4:
> - clarify comment
Acked-by: Neal Cardwell <ncardwell@google.com>
Thanks!
neal
next prev parent reply other threads:[~2019-09-14 15:46 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-13 23:23 [PATCH v5 1/2] tcp: Add TCP_INFO counter for packets received out-of-order Thomas Higdon
2019-09-13 23:23 ` [PATCH v5 2/2] tcp: Add snd_wnd to TCP_INFO Thomas Higdon
2019-09-13 23:36 ` Yuchung Cheng
2019-09-14 15:45 ` Neal Cardwell [this message]
2019-09-14 17:57 ` Soheil Hassas Yeganeh
2019-09-16 14:39 ` David Miller
2019-09-14 15:43 ` [PATCH v5 1/2] tcp: Add TCP_INFO counter for packets received out-of-order Neal Cardwell
2019-09-16 17:42 ` Thomas Higdon
2019-09-16 14:39 ` David Miller
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