From: Eric Dumazet <eric.dumazet@gmail.com>
To: renaud sallantin <renaud.sallantin@gmail.com>
Cc: "Steinar H. Gunderson" <sesse@samfundet.no>,
bloat <bloat@lists.bufferbloat.net>
Subject: Re: [Bloat] AQM creeping into L2 equipment
Date: Fri, 21 Mar 2014 08:06:19 -0700 [thread overview]
Message-ID: <1395414379.6441.17.camel@edumazet-glaptop2.roam.corp.google.com> (raw)
In-Reply-To: <CAAvOmMtt1RCpBfT1MPNh-2FRhQ1GN4xYbfNPLYJwfP6CaP5vow@mail.gmail.com>
On Fri, 2014-03-21 at 09:15 +0100, renaud sallantin wrote:
>
> FQ/pacing enables to do a lot of things,
> and as I already said, it could be used to easily implement the
> Initial Spreading.
> (we did it and it' s just a few lines to add, and a couple of
> parameters to change)
>
>
> But for the moment, FQ/Pacing sends the IW in one burst (up to 10
> segments).
>
This is not true. This depends on RTT and your qdisc parameters.
Whole point of TSO autosizing is to make all this stuff automatic.
Here is the tcpdump output for a 10ms RTT, which is quite standard.
You can see 5 packets are sent, with a delay of more than 1 ms.
07:58:52.616379 IP 10.246.11.51.39905 > 10.246.11.52.41276: S 2187811646:2187811646(0) win 29200 <mss 1460,nop,nop,sackOK,nop,wscale 6>
07:58:52.626575 IP 10.246.11.52.41276 > 10.246.11.51.39905: S 81785763:81785763(0) ack 2187811647 win 29200 <mss 1460,nop,nop,sackOK,nop,wscale 7>
07:58:52.626642 IP 10.246.11.51.39905 > 10.246.11.52.41276: . ack 1 win 457
07:58:52.626671 IP 10.246.11.51.39905 > 10.246.11.52.41276: . 1:2921(2920) ack 1 win 457
07:58:52.627740 IP 10.246.11.51.39905 > 10.246.11.52.41276: . 2921:5841(2920) ack 1 win 457
07:58:52.628815 IP 10.246.11.51.39905 > 10.246.11.52.41276: . 5841:8761(2920) ack 1 win 457
07:58:52.629946 IP 10.246.11.51.39905 > 10.246.11.52.41276: . 8761:11681(2920) ack 1 win 457
07:58:52.631054 IP 10.246.11.51.39905 > 10.246.11.52.41276: . 11681:14601(2920) ack 1 win 457
07:58:52.637147 IP 10.246.11.52.41276 > 10.246.11.51.39905: . ack 2921 win 274
07:58:52.637207 IP 10.246.11.51.39905 > 10.246.11.52.41276: . 14601:17521(2920) ack 1 win 457
07:58:52.638117 IP 10.246.11.51.39905 > 10.246.11.52.41276: . 17521:20441(2920) ack 1 win 457
07:58:52.638114 IP 10.246.11.52.41276 > 10.246.11.51.39905: . ack 5841 win 320
07:58:52.639011 IP 10.246.11.51.39905 > 10.246.11.52.41276: . 20441:23361(2920) ack 1 win 457
You also can tune /proc/sys/net/ipv4/tcp_min_tso_segs from 2 to 1 if you
really want...
No kernel patches needed...
next prev parent reply other threads:[~2014-03-21 15:06 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-18 14:52 Steinar H. Gunderson
2014-03-18 17:17 ` Dave Taht
2014-03-18 17:53 ` Steinar H. Gunderson
2014-03-19 22:22 ` Steinar H. Gunderson
2014-03-18 18:05 ` Fred Baker (fred)
2014-03-18 18:54 ` Dave Taht
2014-03-20 16:20 ` Toke Høiland-Jørgensen
2014-03-20 16:29 ` Dave Taht
2014-03-20 16:44 ` Toke Høiland-Jørgensen
2014-03-20 17:14 ` Dave Taht
2014-03-20 19:34 ` Aaron Wood
2014-03-20 20:23 ` Dave Taht
2014-03-20 23:41 ` Eric Dumazet
2014-03-20 23:45 ` Steinar H. Gunderson
2014-03-20 23:54 ` Steinar H. Gunderson
[not found] ` <CAAvOmMtt1RCpBfT1MPNh-2FRhQ1GN4xYbfNPLYJwfP6CaP5vow@mail.gmail.com>
2014-03-21 15:06 ` Eric Dumazet [this message]
[not found] ` <CAAvOmMvPpmuW1chTdX86s5sQv6X_c622k8YrjW+hN8e5JV+dzA@mail.gmail.com>
2014-03-21 17:51 ` Eric Dumazet
2014-03-21 18:08 ` Dave Taht
2014-03-21 22:00 ` Eric Dumazet
2014-03-21 22:13 ` Dave Taht
2014-03-23 19:27 ` Eric Dumazet
2014-03-21 13:41 ` Toke Høiland-Jørgensen
2014-03-21 15:39 ` Dave Taht
2014-03-21 16:42 ` Steinar H. Gunderson
2014-03-21 18:34 ` Toke Høiland-Jørgensen
2014-03-24 23:16 ` David Lang
2014-03-20 18:16 ` [Bloat] AQM creeping into L2 equipment / 10G not-for-profit playground at tetaneutral.net Laurent GUERBY
2014-03-18 18:57 ` [Bloat] AQM creeping into L2 equipment Dave Taht
2014-03-18 21:06 ` Steinar H. Gunderson
2014-03-19 13:11 ` Nikolay Shopik
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