tech-net archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: wm(4) performance issues

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
> rates are rather disappointing considering the speeds obtained under
> Linux can reach 90+ Mbyte/s.
> The peer machines I've used for testing are either a nforce4 nfe(4)
> or a BCM5705 (32-bit Legacy PCI) bge(4) alone on a Intel 6300ESB's PCI-X
> bus. Both of these boxes run NetBSD-current > 4.99.30.
> Testing consists of my usual sending of /dev/zero via progress(1)
> and pkgsrc/net/netcat6.
> Any ideas how the performance of this wm(4) could be improved?

Well, it appears that the interrupt moderation timers are to
blame.  But that's odd, as the commit that adjusted them recently
claimed that they were changed to improve performance.

It's almost like the chip I have has some sort of
limit as to how many packets it will allow to be
received for a single interrupt (which are already
limited by the moderation timers).

        Jonathan Kollasch

Attachment: pgplk_gthYERW.pgp
Description: PGP signature

Home | Main Index | Thread Index | Old Index