From mboxrd@z Thu Jan  1 00:00:00 1970
From: Lawrence Brakmo <brakmo@fb.com>
Subject: Re: [PATCH net-next] tcp: ack immediately when a cwr packet arrives
Date: Tue, 24 Jul 2018 17:42:46 +0000
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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>
To: Neal Cardwell <ncardwell@google.com>,
        Yuchung Cheng <ycheng@google.com>
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Note that without this fix the 99+ACU- 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 3759824da87b30ce7a=
35b4873b62b0ba38905ef5 in Jul 2015, which triggered the bugs/features we ar=
e fixing/adding. I agree it is a debatable whether it is a bug fix or a fea=
ture improvement and I am fine either way.

Lawrence

+/v8-On 7/24/18, 10:13 AM, +ACI-Neal Cardwell+ACI- +ADw-ncardwell+AEA-googl=
e.com+AD4- wrote:

    On Tue, Jul 24, 2018 at 1:07 PM Yuchung Cheng +ADw-ycheng+AEA-google.co=
m+AD4- wrote:
    +AD4-
    +AD4- On Mon, Jul 23, 2018 at 7:23 PM, Daniel Borkmann +ADw-daniel+AEA-=
iogearbox.net+AD4- wrote:
    +AD4- +AD4- Should this go to net tree instead where all the other fixe=
s went?
    +AD4- I am neutral but this feels more like a feature improvement
   =20
    I agree this feels like a feature improvement rather than a bug fix.
   =20
    neal
   =20