Re: wm(4) performance issues

[Thor Lancelot Simon <tls%rek.tjls.com@localhost>]

On Wed, Mar 05, 2008 at 03:46:06PM -0600, Jonathan A. Kollasch wrote:
> Hi,
> 
> I recently picked up a Intel Pro/1000 PT Desktop wm(4).
> (Because nfe(4) was rather unhappy for me. But that's another
> story.)
> 
> I was surprised to find it has performance issues under NetBSD.
> 
> On a amd64 4.99.54 box (Socket 754, nforce4) I couldn't get it to source
> or sink much more than 25 Mbyte/s.  On another instance of the same model
> of motherboard running 4.99.31, 57 Mbyte/s was obtainable.  Both of these

This is a single-stream test?  What are your send and receive socket buffer
sizes at each end?

Tuning the driver (almost any driver, really) for 1Gbit/sec throughput with
our tiny default socket buffer sizes requires an unacceptably high interrupt
rate limit and CPU consumption.  With reasonable socket buffer sizes for
gigabit networking, the driver seems to perform quite well for me (though
I think Simon is going to check in some more adjustments to the interrupt
timer code soon).

Thor