> 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?

did you try bumping up NKPDE (see i386/include/pmap.h)?


The kernel can only map a limited amount of virtual address space,
i believe it's NKPDE * 4M, which in this case would be 28M.

BUFPAGES -> bufpages, and if you don't also set NBUF, bufpages -> nbuf.

The kernel wants to allocate (MAXBSIZE * NBUF) of kv space.

MAXBSIZE is 16k, currently (this is a bug; it should really be
larger!), so that means that you end up wanting to allocate:
	nbuf * MAXBSIZE == 1536 * 16k == 24M
of virtual space for buffers...

Now do you wonder why you panic?  8-)


This is a long-standing and quite serious (and not even that difficult
to fix) bug in the i386 port, that (as far as I'm aware) both FreeBSD
and BSDI have fixed.



chris