From: Lawrence Brakmo <brakmo@fb.com>
To: Neal Cardwell <ncardwell@google.com>, Yuchung Cheng <ycheng@google.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
Netdev <netdev@vger.kernel.org>, Kernel Team <Kernel-team@fb.com>,
Alexei Starovoitov <ast@fb.com>,
"Eric Dumazet" <eric.dumazet@gmail.com>
Subject: Re: [PATCH net-next] tcp: ack immediately when a cwr packet arrives
Date: Tue, 24 Jul 2018 17:42:46 +0000 [thread overview]
Message-ID: <36385AF4-4EE4-4237-84B8-1978B091E28B@fb.com> (raw)
In-Reply-To: <CADVnQynbJPtHSJuYoS6fEKdo-2Q_P4VXAa=ytz+NHMM+0dcLmA@mail.gmail.com>
Note that without this fix the 99% latencies when doing 10KB RPCs in a congested network using DCTCP are 40ms vs. 190us with the patch. Also note that these 40ms high tail latencies started after commit 3759824da87b30ce7a35b4873b62b0ba38905ef5 in Jul 2015, which triggered the bugs/features we are fixing/adding. I agree it is a debatable whether it is a bug fix or a feature improvement and I am fine either way.
Lawrence
On 7/24/18, 10:13 AM, "Neal Cardwell" <ncardwell@google.com> wrote:
On Tue, Jul 24, 2018 at 1:07 PM Yuchung Cheng <ycheng@google.com> wrote:
>
> On Mon, Jul 23, 2018 at 7:23 PM, Daniel Borkmann <daniel@iogearbox.net> wrote:
> > Should this go to net tree instead where all the other fixes went?
> I am neutral but this feels more like a feature improvement
I agree this feels like a feature improvement rather than a bug fix.
neal
next prev parent reply other threads:[~2018-07-24 18:50 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-24 0:49 [PATCH net-next] tcp: ack immediately when a cwr packet arrives Lawrence Brakmo
2018-07-24 2:15 ` Neal Cardwell
2018-07-24 2:23 ` Daniel Borkmann
2018-07-24 17:06 ` Yuchung Cheng
2018-07-24 17:12 ` Neal Cardwell
2018-07-24 17:26 ` Eric Dumazet
2018-07-24 17:42 ` Lawrence Brakmo [this message]
2018-07-25 1:57 ` Neal Cardwell
2018-07-25 23:21 ` David Miller
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