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Re: wm(4) performance issues



On Sat, Mar 08, 2008 at 09:07:20AM -0500, Thor Lancelot Simon wrote:
> 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?

Single stream I believe.  Defaults.

> 
> 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).

Ah.  I just find it a bit odd that wm(4) is different and possibly
perceived as worse than say, a low-end bge(4) or integrated nfe(4).

I was able to tune the moderation timers (mostly based on the
defaults in FreeBSD's em(4)) to get 950 to 980 mbit/s with
kttcp. However, I didn't bother to get a baseline from
before I adjusted them. :/

BTW,
What are the best ways to test this sort of thing?

        Jonathan Kollasch

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