[fedora-arm] smsc95xx performance bug: eth vs usb

[DJ Delorie]

> Can you put the ethernet and storage on different hubs? (it may not be..)

No, it's all on-board.  No other hubs, all board-powered.

> Or do you see similar crappy performance with the nic adapter  
> unplugged and unused?

I see the same crappy performance with the smsc95xx driver unloaded,
net down, cable unplugged.

That gave me an idea, though... I unloaded the smsc95xx driver, and
plugged in a serial port connected to a 9600 baud character generator,
and got good performance.  Likewise with a usb mouse, as long as I
wiggled the mouse during the test.

Note: I get crappy performance with the network *up*, as long as
there's no traffic.

If I plug in *two* usb-storage devices (er, flash stick and sata
dock), I get the same crappy performance for both of them (i.e. same
per-drive throughput as the single-drive crappy performance).