NIC with polling support

NIC with polling support

[Florian Weimer]

Dear all,

I guess I'm severe need of a 100BaseTX NIC with polling support in the
driver.

A special application requires processing of 40,000 packets/second or
more, and the interrupt load currently kills the machine (i.e. no
scheduling during peak load).

Any suggestions which card I should use?  The driver has to be open
source, and the card shouldn't be too expensive (i.e. in the usual
price range of brand 100BaseTX NICs).

Thanks,
-- 
Florian Weimer 	                  Weimer@CERT.Uni-Stuttgart.DE
University of Stuttgart           http://CERT.Uni-Stuttgart.DE/people/fw/
RUS-CERT                          fax +49-711-685-5898

Re: NIC with polling support

[Ion Badulescu]

On Tue, 31 Dec 2002 17:35:19 +0100, Florian Weimer <Weimer@cert.uni-stuttgart.de> wrote:
> Dear all,
> 
> I guess I'm severe need of a 100BaseTX NIC with polling support in the
> driver.
> 
> A special application requires processing of 40,000 packets/second or
> more, and the interrupt load currently kills the machine (i.e. no
> scheduling during peak load).
> 
> Any suggestions which card I should use?  The driver has to be open
> source, and the card shouldn't be too expensive (i.e. in the usual
> price range of brand 100BaseTX NICs).

As far as I can tell, no driver in 2.4 supports NAPI (aka polling support)
with the exception of the tg3 driver -- but that's a GigE card.

The Adapter DuraLAN/Starfire driver (which I maintain) has been modified to
support NAPI, but those changes have not yet been included in the official
kernel. I can mail you the patch, if you want to give it a try. The cards
are on the expensive side, but not overly so (about $100/port).

Ion

-- 
  It is better to keep your mouth shut and be thought a fool,
            than to open it and remove all doubt.

Re: NIC with polling support

[Jason Lunz]

Weimer@CERT.Uni-Stuttgart.DE said:
> Any suggestions which card I should use?  The driver has to be open
> source, and the card shouldn't be too expensive (i.e. in the usual
> price range of brand 100BaseTX NICs).

linux 2.4.20 supports NAPI for tg3 only. I have patches for e1000,
3c59x, tulip, and eepro100 at:

	http://gtf.org/lunz/linux/net/

The tulip patch might be a bit outdated. The only one of these patches
that I've personally tested extensively is e1000, and it works well
under extremely high interrupt load. e1000 cards are getting cheap
enough to be considered as 100BaseTX NICs, and they perform well doing
that.

Napi patches also exist for dl2k and a few other drivers, but I'm not
sure where.

Jason

Re: NIC with polling support

[Florian Weimer]

Jason Lunz <lunz@falooley.org> writes:

> Weimer@CERT.Uni-Stuttgart.DE said:
>> Any suggestions which card I should use?  The driver has to be open
>> source, and the card shouldn't be too expensive (i.e. in the usual
>> price range of brand 100BaseTX NICs).
>
> linux 2.4.20 supports NAPI for tg3 only. I have patches for e1000,
> 3c59x, tulip, and eepro100 at:

Thanks, the 3c59x patches are interesting, but they contain a few
_very_ discouraging comments. :-(

I might give the e100 patches a try, or borrow/buy an e1000 card--does
a "PRO/1000 MT Desktop Adapter" do it?

If I go the e100 route, does it matter much which chip the card is
built around?  (The CPU Saver feature seems to be available only on
82558/9, and I haven't found those yet.)

-- 
Florian Weimer 	                  Weimer@CERT.Uni-Stuttgart.DE
University of Stuttgart           http://CERT.Uni-Stuttgart.DE/people/fw/
RUS-CERT                          fax +49-711-685-5898

Re: NIC with polling support

[Florian Weimer]

Jason Lunz <lunz@falooley.org> writes:

[snip]

Sorry for writing this publicly, but maybe Jason can read it this way:

  lunz@falooley.org
    SMTP error from remote mailer after RCPT TO:<lunz@falooley.org>:
    host temp123.org [128.61.35.118]: 554 <lunz@falooley.org>:
    Recipient address rejected: Relay access denied


Jason, you might want to fix this...

-- 
Florian Weimer 	                  Weimer@CERT.Uni-Stuttgart.DE
University of Stuttgart           http://CERT.Uni-Stuttgart.DE/people/fw/
RUS-CERT                          fax +49-711-685-5898