Subject: Re: NetBSD TCP performance (was: Yet more fun)
To: Michael Lyle <mlyle@recourse.net>
From: Jason R Thorpe <thorpej@zembu.com>
List: port-i386
Date: 03/30/2001 15:59:23
On Fri, Mar 30, 2001 at 03:42:20PM -0800, Michael Lyle wrote:

 > 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.

You might try updating to the latest netbsd-1-5 branch kernel sources
(you'll be able to do this w/ anoncvs).  Frank van der Linden committed
a change to that branch which correct some of this -- the in4_cksum()
routine wasn't an optimized version, but is what is used by the code,
but now it is.

This was an oversight that happened when IPv6 was integrated into the
system.

-- 
        -- Jason R. Thorpe <thorpej@zembu.com>