CoDel AQM discussions
 help / color / mirror / Atom feed
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Jim Gettys <jg@freedesktop.org>
Cc: codel@lists.bufferbloat.net
Subject: Re: [Codel] usage of 'count' in codel
Date: Sun, 06 May 2012 20:15:40 +0200	[thread overview]
Message-ID: <1336328140.3752.2014.camel@edumazet-glaptop> (raw)
In-Reply-To: <4FA6B2FB.2030809@freedesktop.org>

On Sun, 2012-05-06 at 13:20 -0400, Jim Gettys wrote:



> I sort of think that having some upper queue time bound makes sense, if
> only to ensure that TCP's quadratic (un)responsiveness never gets out of
> hand.  But we agreed that having an implementation we could play with to
> observe reality would likely be better than hand-waving with no
> experience about how long the queue should be allowed to grow.

Even with normal tcp flows, codel is not responsive enough and too
conservative as is.

drop_next = control_law(drop_next)   with interval/sqrt(count)
increments ?

Something is _really_ wrong.

Thats few drops per second when we need far more than this.

interval = 100ms so you need count = 10000 to reach the rate of one drop
per ms, regardless of the link capacity.

control loop has no input on time of residence of packets.




  parent reply	other threads:[~2012-05-06 18:15 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CAA93jw7bnQED7QXc_jgsEyf-ydR0Bo-OazBZOTXDQ9nYYCgpJw@mail.gmail.com>
     [not found] ` <1336281092.3752.982.camel@edumazet-glaptop>
     [not found]   ` <1336283203.3752.1032.camel@edumazet-glaptop>
     [not found]     ` <1336315913.3752.1598.camel@edumazet-glaptop>
     [not found]       ` <1336324134.3752.1825.camel@edumazet-glaptop>
2012-05-06 17:20         ` Jim Gettys
2012-05-06 17:58           ` dave taht
2012-05-06 18:25             ` Simon Barber
2012-05-06 18:41               ` Dave Taht
2012-05-06 18:48               ` Eric Dumazet
2012-05-06 18:15           ` Eric Dumazet [this message]
2012-05-06 18:26             ` Dave Taht
2012-05-06 18:49               ` Eric Dumazet
2012-05-06 19:15                 ` Dave Taht
2012-05-06 19:47                   ` Eric Dumazet

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://lists.bufferbloat.net/postorius/lists/codel.lists.bufferbloat.net/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1336328140.3752.2014.camel@edumazet-glaptop \
    --to=eric.dumazet@gmail.com \
    --cc=codel@lists.bufferbloat.net \
    --cc=jg@freedesktop.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox