Subject: Re: NetBSD TCP performance
To: Michael Lyle <mlyle@recourse.net>
From: Manuel Bouyer <bouyer@antioche.lip6.fr>
List: port-i386
Date: 03/31/2001 17:51:27
On Fri, Mar 30, 2001 at 03:42:20PM -0800, Michael Lyle wrote:
> I've been helping out Larry Colen with a lot of the stuff he's been
> mailing the list about.. (Recourse is a network security company and
> we're updating our "traffic generation" setup for testing our 
> intrusion detection engine).  
> 
> Our overall methodology is that we are using thttpd and a program
> that we've developed in-house called "traffique".  Traffique iterates
> a finite automata through the steps of doing a HTTP get to the thttpd
> server. 
> 
> We're using a pair of Dell Poweredge 350's with 2 i82559 onboard NIC's.
> They're set up to be thttpd servers and to retrieve pages from each other.
> 
> On linux, we do about 97mbit/sec (filling up the TX rings on the card,
> so this corresponds to network saturation).  On NetBSD, we can do only
> about 65-70mbit/sec.  I have a feeling this has to do with serialization
> of various TCP/driver operations.  I've experimented lightly with turning
> up window sizes etc and it doesn't seem to have much effect.

Do you notice any disk activity when running this test with NetBSD, that
wouldn't be there with linux ?
linux uses a dynamically-sized buffer cache, where NetBSD uses a static one.
It's possible that files served by thttpd all fits in buffer cache under
linux, and require some disk access under NetBSD.

--
Manuel Bouyer <bouyer@antioche.eu.org>
--