All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Mariusz Janiak" <mariuszjaniak@wp.pl>
To: Norbert Lange <nolange79@gmail.com>
Cc: Xenomai <xenomai@xenomai.org>
Subject: [Xenomai] Odp:  RtNet and Interrupts
Date: Fri, 17 Feb 2017 11:45:54 +0100	[thread overview]
Message-ID: <58a6d462bfc384.64095769@wp.pl> (raw)

Dnia Piątek, 17 Lutego 2017 11:18 Norbert Lange <nolange79@gmail.com> napisał(a) 
> Hello,
> 
> I wonder if the Rtnet Stack is driven at packet level, ie. if after
> every one received packet( or even buffer) an IRQ is received.
> I worked on a Project where a similar Problem with Ethernet
> communication had to be solved, and I just queued up enough receive
> buffers and just picked up anything that arrived at the start of a
> timeslot.
> 
> On 100Mbit and a 1ms timeslot, I calculated a max. of 150 received
> pakets. Not that realtime communication can get anywhere close to
> that, but you have to deal with worst cases and guarantee that your
> system aint missing the cpu time spend in IRQs for other things - even
> if you just decide to drop all those packets, the IRQ overhead would
> be there.
> 
> So is Rtnet using "polling" at timeslots, or irqs?

Hi,

As far as I know, RTnet is interrupt driven stack, it means that after reception of each packet the interrupt is generated and handled by the NIC driver. This is one of the reasons why porting of the RT driver  to new NICs is so problematic, especially now when new drivers support NAPI.

> Kind Regards,
> Norbert
> 
> PS.
> Complete unrelated, but are there any big companies using Xenomai /
> Rtnet that can be named?

I know that Universities use it a lot in the field of robotics (eg. SOEM + OROCOS). There is a port of the RTnet stack for microcontrolers if you are interested (RTnet Embedded)

https://bitbucket.org/mariuszjaniak/rtnet-embedded

Best regards,
Mariusz



> _______________________________________________
> Xenomai mailing list
> Xenomai@xenomai.org
> https://xenomai.org/mailman/listinfo/xenomai





             reply	other threads:[~2017-02-17 10:45 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-17 10:45 Mariusz Janiak [this message]
2017-02-17 11:19 ` [Xenomai] RtNet and Interrupts Norbert Lange

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

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

  git send-email \
    --in-reply-to=58a6d462bfc384.64095769@wp.pl \
    --to=mariuszjaniak@wp.pl \
    --cc=nolange79@gmail.com \
    --cc=xenomai@xenomai.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.