on 10/18/01 1:23 PM, Jason R Thorpe at thorpej@wasabisystems.com wrote:
[info about fixes to make gem ethernet driver work on macppc deleted]

I've been doing a bit of stress-testing with the gem driver on macppc, and
it seems to be cracking under the strain.

I'm using ftp transfers of large files as a simple benchmark/stress test,
and running `netstat -wb 1` in another window to watch throughput on the
interface during the transfer.  My testing setup has two G4 desktops (a dual
450 and a single 466) running NetBSD-current and a G3/400 Powerbook running
Mac OS X, all plugged directly into a 100baseT switch (Netgear FS108).  All
three are 100baseT-capable, and both of the desktops are gigabit-capable.
All of my tests have been at 100Mbit, since gigabit support isn't functional
in either driver.

The gm driver seems to work well in all the tests I've tried.  Transfer
speeds are just shy of 10MB/sec, and I haven't seen any anomolous
behavior.

Transfers _to_ the machine using the gem driver run at close to 10MB/sec.

Transfers _from_ the machine using the gem driver run at widely varying
speed, but usually less than 1MB/sec.  They also cause periodic console
messages which say:

    MAC rx fault, status 5

Continued testing causes the interface to stuff up completely after a few
minutes.  There are no console messages when it reaches this state, but once
it does, absolutely nothing will pass.  I've seen this a couple of times:

    [root@kenny monroe]# ping xxx.xxx.xxx.xx
    PING xxx.xxx.xxx.xx (xxx.xxx.xxx.xx): 56 data bytes
    ping: sendto: No buffer space available
    ping: sendto: No buffer space available
    ^C
    ----xxx.xxx.xxx.xx PING Statistics----
    2 packets transmitted, 0 packets received, 100.0% packet loss
    [root@kenny monroe]#

I've never seen this particular error message before, but it looks ominous.

One of the G4s needs to go into production pretty soon, and I'm planning to
use the gm driver on it unless there's some good news about the gem driver
by early next week.

The other G4 is my regular desktop machine, which usually runs Mac OS X but
can boot into NetBSD for testing new kernel builds before putting them on
the production machine.  This will allow me to continue trying new kernel
builds to see if we can get the gem driver working better, and gigabit
support enabled.

-- monroe
------------------------------------------------------------------------
Monroe Williams                                  monroe@criticalpath.com