This will allow improvements to the pmaps so that they can more easily defer expensive operations, eg tlb/cache flush, til the last possible moment.
Currently this is a no-op on most platforms, so they should see no difference.
Reviewed by Jason.
which have pmap_steal_memory(). This is to reduce the API differences
between pmaps that implement pmap_steal_memory() and pmaps which do
not.
Note that pmap_steal_memory() needs to adjust *vstartp and/or
*vendp only if it used addresses within the range provided to UVM
via the pmap_virtual_space() call. I.e. it is not necessary to do
so in any current pmap_steal_memory() implementation.
<vm/vm_extern.h> merged into <uvm/uvm_extern.h>
<vm/vm_page.h> merged into <uvm/uvm_page.h>
<vm/pmap.h> has become <uvm/uvm_pmap.h>
this leaves just <vm/vm.h> in NetBSD.
