> The place where we get severe inefficiencies here is the process of
> walking the active and inactive lists.  Due to the high-level
> operations done on physical pages, the pmap module is forced to keep a
> list of virtual mappings (the pv_list) for each physical page, and to
> walk that list when these operations are done.  There are some
> problems with this:

On Sparc, and smaller mips systems, the cache is virtually indexed, so
the pmap module needs this information to enforce cache coherency.
Routines like pmap_copy_page() currently receive only physical addresses,
and so they use the pv_list to flush the correct cache lines.

Just thought I should bring up another requirement before people try to
engineer them away.

	-castor