> From: Chris Torek <torek@BSDI.COM>
> The PROM turns all the caches on, and you cannot turn them off
> again because they are write-back.  

What function is then served by the code in cache_enable?  Can I
convince the PROM to never turn the caches on to start with, perhaps?

> (You could, in theory, turn
> them off if you pushed out all dirty cache data first, but why
> bother?)

Research -- to measure the performance improvement the presence of the
caches give you for different types of programs, and to study the
interactions of the VM system with the various caches.  I'm sure there
are more reasons others might want to, but those are mine.

Jeremy