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From: Neal Cardwell <ncardwell@google.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jonathan Morton <chromatix99@gmail.com>,
	Michael Welzl <michawe@ifi.uio.no>, David Ros <dros@simula.no>,
	bloat <bloat@lists.bufferbloat.net>,
	 Yuchung Cheng <ycheng@google.com>, Wei Wang <weiwan@google.com>
Subject: Re: [Bloat] benefits of ack filtering
Date: Thu, 30 Nov 2017 10:57:07 -0500	[thread overview]
Message-ID: <CADVnQymON1wQ=-i2W1ooqZ41Hyez03i1tUYb_qE-bdTFcMPpiQ@mail.gmail.com> (raw)
In-Reply-To: <1512057319.19682.16.camel@gmail.com>

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On Thu, Nov 30, 2017 at 10:55 AM, Eric Dumazet <eric.dumazet@gmail.com>
wrote:

> On Thu, 2017-11-30 at 09:51 -0500, Neal Cardwell wrote:
> > On Thu, Nov 30, 2017 at 5:24 AM, Eric Dumazet <eric.dumazet@gmail.com
> > > wrote:
> > > I agree that TCP itself should generate ACK smarter, on receivers
> > > that
> > > are lacking GRO. (TCP sends at most one ACK per GRO packets, that
> > > is
> > > why we did not feel an urgent need for better ACK generation)
> > >
> > > It is actually difficult task, because it might need an additional
> > > timer, and we were reluctant adding extra complexity for that.
> >
> > How about just using the existing delayed ACK timer, and just making
> > the delayed ACK logic a bit smarter? We could try using the existing
> > logic and timers, but using something adaptive instead of the magic
> > "2" MSS received to force an ACK.
>
> Keep in mind some distros have HZ=250 or even HZ=100
>
> So even a 'one jiffie' timer could add 10ms delay.
>

Right, good point. I forgot about those cases. :-)

neal

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  reply	other threads:[~2017-11-30 15:57 UTC|newest]

Thread overview: 76+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-28 21:48 Dave Taht
2017-11-29  6:09 ` Mikael Abrahamsson
2017-11-29  9:34   ` Sebastian Moeller
2017-11-29 12:49     ` Mikael Abrahamsson
2017-11-29 13:13       ` Luca Muscariello
2017-11-29 14:31         ` Mikael Abrahamsson
2017-11-29 14:36           ` Jonathan Morton
2017-11-29 15:24             ` Andrés Arcia-Moret
2017-11-29 15:53           ` Luca Muscariello
     [not found]             ` <CAJq5cE3qsmy8EFYZmQsLL_frm8Tty9Gkm92MQPZ649+kpM1oMw@mail.gmail.com>
2017-11-29 16:13               ` Jonathan Morton
2017-11-30  7:03             ` Michael Welzl
2017-11-30  7:24               ` Dave Taht
2017-11-30  7:45               ` Dave Taht
2017-11-30  7:48               ` Jonathan Morton
2017-11-30  8:00                 ` Luca Muscariello
2017-11-30 10:24                 ` Eric Dumazet
2017-11-30 13:04                   ` Mikael Abrahamsson
2017-11-30 15:51                     ` Eric Dumazet
2017-12-01  0:28                     ` David Lang
2017-12-01  7:09                       ` Jan Ceuleers
2017-12-01 12:53                         ` Toke Høiland-Jørgensen
2017-12-01 13:13                           ` [Bloat] [Make-wifi-fast] " Кирилл Луконин
2017-12-01 13:22                             ` Luca Muscariello
2017-12-11 17:42                             ` Simon Barber
2017-12-01 13:17                           ` [Bloat] " Luca Muscariello
2017-12-01 13:40                             ` Toke Høiland-Jørgensen
2017-12-01 17:42                               ` Dave Taht
2017-12-01 20:39                                 ` Juliusz Chroboczek
2017-12-03  5:20                                   ` [Bloat] [Make-wifi-fast] " Bob McMahon
2017-12-03 10:35                                     ` Juliusz Chroboczek
2017-12-03 11:40                                       ` Jan Ceuleers
2017-12-03 13:57                                         ` Juliusz Chroboczek
2017-12-03 14:07                                           ` Mikael Abrahamsson
2017-12-03 19:53                                             ` Juliusz Chroboczek
2017-12-03 14:09                                           ` Ryan Mounce
2017-12-03 19:54                                             ` Juliusz Chroboczek
2017-12-03 20:14                                               ` Sebastian Moeller
2017-12-03 22:27                                                 ` Dave Taht
2017-12-03 15:25                                           ` Robert Bradley
2017-12-04  3:44                                         ` Dave Taht
2017-12-04 14:38                                           ` David Collier-Brown
2017-12-04 15:44                                             ` Juliusz Chroboczek
2017-12-04 17:17                                               ` David Collier-Brown
2017-12-03 19:04                                       ` Bob McMahon
2017-12-01 21:17                                 ` Bob McMahon
2017-12-01  8:45                       ` [Bloat] " Sebastian Moeller
2017-12-01 10:45                         ` Luca Muscariello
2017-12-01 18:43                           ` Dave Taht
2017-12-01 18:57                             ` Luca Muscariello
2017-12-01 19:36                               ` Dave Taht
2017-11-30 14:51                   ` Neal Cardwell
2017-11-30 15:55                     ` Eric Dumazet
2017-11-30 15:57                       ` Neal Cardwell [this message]
2017-11-29 16:50       ` Sebastian Moeller
2017-12-12 19:27         ` Benjamin Cronce
2017-12-12 20:04           ` Dave Taht
2017-12-12 21:03           ` David Lang
2017-12-12 21:29             ` Jonathan Morton
2017-12-12 22:03           ` Jonathan Morton
2017-12-12 22:21             ` David Lang
     [not found]               ` <CAJq5cE3nfSQP0GCLjp=X0T-iHHgAs=YUCcr34e3ARgkrGZe-wg@mail.gmail.com>
2017-12-12 22:41                 ` Jonathan Morton
2017-12-13  9:46                   ` Mikael Abrahamsson
2017-12-13 10:03                     ` Jonathan Morton
2017-12-13 12:11                       ` Sebastian Moeller
2017-12-13 12:18                         ` Jonathan Morton
2017-12-13 12:36                     ` Sebastian Moeller
2017-12-13 12:39             ` Luca Muscariello
2017-11-29 18:21   ` Juliusz Chroboczek
2017-11-29 18:41     ` Dave Taht
2017-11-29 23:29       ` Steinar H. Gunderson
2017-11-29 23:59       ` Stephen Hemminger
2017-11-30  0:21         ` Eric Dumazet
2017-12-11 20:15   ` Benjamin Cronce
2017-11-29 18:28 ` Juliusz Chroboczek
2017-11-29 18:48   ` Dave Taht
2017-12-11 18:30   ` Jonathan Morton

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