>Is using pmap_page_protect() on a wired page legal?  The daemon book it
>says that pmap_page_protect() is used to manage pageable pages, but if a
>page is wired then it's not pageable, is it?  Is this a bug in UVM?

that's a good question.  looking over my notes, it is possible to have 
pmap_page_protect() called on a wired page in both old VM and UVM.  so
it should "work" ... as to if that should be "legal" ... that's another 
question.   there are some issues relating to how wired memory should
work when it is shared or flushed to backing store that were not addessed
in the old VM system and i didn't do much about them in UVM.

chuck