Sluggishness on a 6 CPU HP-6000 Netserver

[David Landgren]

Hello,

I have just installed an HP-6000r Netserver with 2Gb RAM and 6 P-III 
700MHz processors.

I cvsupped src (4.10-STABLE) yesterday and built the world and kernel. 
I've stripped out just about everything else I can from the kernel: usb, 
firewire, apm, serial port, //l port, PCMCIA, other RAID/SCSI/network 
drivers.

The kernel has dummynet support. I have tried option HZ=x, for x=1000, 
200, 100 but network response is sluggish. I haven't specifically 
referred to any dummynet features in my ipfw ruleset.

When I type quickly I can run several characters ahead of the display, 
which jerks along behind. Display output, e.g. when compiling the 
kernel, is also jerky. From the console the response is crisp.

Both the switch to which the box is connected (a Cisco Catalyst) and the 
fxp network driver are hard-coded to 100baseTX full-duplex.

netstat -m:
70/480/26624 mbufs in use (current/peak/max):
         66 mbufs allocated to data
         4 mbufs allocated to packet headers
64/128/6656 mbuf clusters in use (current/peak/max)
376 Kbytes allocated to network (1% of mb_map in use)
0 requests for memory denied
0 requests for memory delayed
0 calls to protocol drain routines

It must be something, but I have no idea what to look {at,for}/what to 
tune. It's the first time I've built dummynet, first time I've used a 
box with more than two CPUs and I wonder if there might be some sort of 
contention happening.

Thanks for any clues I can use.

David