Development issues regarding the cerowrt test router project
 help / color / mirror / Atom feed
From: Hal Murray <hmurray@megapathdsl.net>
To: Dave Taht <dave.taht@gmail.com>
Cc: codel@lists.bufferbloat.net, hmurray@megapathdsl.net,
	bloat-devel <bloat-devel@lists.bufferbloat.net>,
	cerowrt-devel@lists.bufferbloat.net
Subject: Re: [Cerowrt-devel] hardware hacking on fq_codel in FPGA form at 10GigE
Date: Thu, 20 Dec 2012 00:17:37 -0800	[thread overview]
Message-ID: <20121220081737.1A681800037@ip-64-139-1-69.sjc.megapath.net> (raw)
In-Reply-To: Message from Dave Taht <dave.taht@gmail.com> of "Thu, 20 Dec 2012 02:28:19 EST." <CAA93jw7h8d5Y8r+_DwR_cF9F7TEWzgZuoYvfOWp5B=1=pGx=BQ@mail.gmail.com>


If I was going to do something like that, I'd build a small/simple CPU and do 
the work in microcode.

> implementing {n,e,s}fq_codel onboard looks very feasible

How many lines of assembler code would it take?

How many registers do you need?  Do you need any memory other than queues?  
Maybe counters?


> The only thing that is seriously serial about fq_codel is shooting the
> biggest flow when the queue limit is exceeded, and that could be made
> embarrassingly parallel with enough gates.There are no doubt other tricky
> issues. 

Would it be better to do the fq work in the main CPU and let the FPGA grab 
packets from some shared  data structure in memory?  Can you work out a 
memory structure that doesn't need locks?


-- 
These are my opinions.  I hate spam.




  reply	other threads:[~2012-12-20  8:17 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <dave.taht@gmail.com>
2012-12-20  7:28 ` Dave Taht
2012-12-20  8:17   ` Hal Murray [this message]
2012-12-20  8:27     ` Jonathan Morton
2012-12-20  9:51       ` Hal Murray
2012-12-20  9:13     ` Dave Taht
2012-12-20  9:26       ` Dave Taht
2012-12-20 10:32         ` Hal Murray
2012-12-20 13:53           ` dpreed
2012-12-20 14:18             ` Dave Taht
2012-12-20 15:05               ` Dave Taht
2012-12-21 12:34                 ` Dave Taht
2012-12-21 17:48                   ` dpreed
2012-12-21 18:14                     ` Jim Gettys
2012-12-21 18:25                       ` dpreed
2012-12-21 18:45                         ` Jim Gettys
2012-12-21 19:34                           ` dpreed
2012-12-21 19:42                             ` Jim Gettys
2012-12-21 21:54                           ` [Cerowrt-devel] [Codel] " David Woodhouse
2012-12-21 21:56                             ` John Crispin
2012-12-21 22:08                               ` David Woodhouse

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/cerowrt-devel.lists.bufferbloat.net/

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

  git send-email \
    --in-reply-to=20121220081737.1A681800037@ip-64-139-1-69.sjc.megapath.net \
    --to=hmurray@megapathdsl.net \
    --cc=bloat-devel@lists.bufferbloat.net \
    --cc=cerowrt-devel@lists.bufferbloat.net \
    --cc=codel@lists.bufferbloat.net \
    --cc=dave.taht@gmail.com \
    /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