Well, I spoke too soon saying that my p133 is copying fine with UVM. I just
had the same panic (at least, ted mentioned to me that he saw a "ptdi"
panic), after doing a make build and several kernel compiles.

I got a crashdump, only my sources are now more recent than my kernel.

The panic originates from a pagefault, where the i386 pmap runs out
of kernel PT pages. In this case, I know that I have enough PT pages
for the kernel, so I suspect that something is leaking kmem pages,
but I haven't really looked further yet.

- Frank