Cake - FQ_codel the next generation
 help / color / mirror / Atom feed
From: Stephen Hemminger <stephen@networkplumber.org>
To: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: cake@lists.bufferbloat.net
Subject: Re: [Cake] the meta problem of memory, locks, and multiple cpus
Date: Mon, 2 Nov 2015 16:55:32 -0800	[thread overview]
Message-ID: <20151102165532.2e714f77@xeon-e3> (raw)
In-Reply-To: <20151029120038.03f09749@redhat.com>

On Thu, 29 Oct 2015 12:00:38 +0100
Jesper Dangaard Brouer <brouer@redhat.com> wrote:

> On Thu, 29 Oct 2015 10:08:34 +0100
> Dave Taht <dave.taht@gmail.com> wrote:
> 
> > The real problem A) that I wish we could solve at the qdisc layer
> > 
> > is that we could size everything more appropriately if we actually
> > *knew* the physical link rate in many cases. It is *right there* in
> > the sys filesystem for ethernet devices, if only there was some way to
> > get at it, and get notifications if it changed.... or merely to know
> > the underlying operating range of the device at qdisc init time. It is
> > dumb to allow 50MB of memory for a 10mbit device just to make the
> > 10GigE folk happy.  
> 
> Well, do you really need to know the link rate?  One of the lessons
> learned from codel (by Kathleen/Van) is that we should not trie to
> measure the link rate, but instead simply look at the time spend in
> queue.

Why not measure the egress rate like PIE?
It is right there in the same code.

Also many devices (like wifi) can't report real link rate.

  reply	other threads:[~2015-11-03  0:55 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-29  9:08 Dave Taht
2015-10-29 11:00 ` Jesper Dangaard Brouer
2015-11-03  0:55   ` Stephen Hemminger [this message]
2015-11-03  1:32     ` Jonathan Morton

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/cake.lists.bufferbloat.net/

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

  git send-email \
    --in-reply-to=20151102165532.2e714f77@xeon-e3 \
    --to=stephen@networkplumber.org \
    --cc=brouer@redhat.com \
    --cc=cake@lists.bufferbloat.net \
    /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