Thor Lancelot Simon writes:
> I have a few systems with quite a bit more memory than they really need.
> 
> I'd like to use it for the buffer cache.

I know that feeling. I've put in a PR (1903 I think) which supports a
BUFCACHE option which sets the % of memory that you want to allocate
as buffer cache. I have my 24MB systems with 15-20% buffercache.
Whilst this is a hack an unnecessary in a unified buffer cache
environment, until we have it, it's a useful hack (IMHO)


> Why is it that setting BUFPAGES > 1536 (actually, perhaps it's a bit higher;
> I know that 2048 definitely does it) causes a ptdi panic early in the
> autoconfig process?

(See other comments re bumping NKPDE. It may be that even with the
 BUFCACHE hack you'll need to bump NKPDE, but I haven't got 64MB in a
 PC to test on, and I don't think that the 5000/240 with 480MB of RAM
 we had running NetBSD/pmax had the same problem ;-)