* Re-organise RID allocation so that we don't accidentally give a RID
to two different processes. Also randomise the order to try to reduce
collisions in VHPT and TLB. Don't allocate RIDs for regions which are
unused.
* Allocate space for VHPT based on the size of physical memory. More
tuning is needed here.
* Add sysctl instrumentation for VHPT - see sysctl vm.stats.vhpt
* Fix a bug in pmap_prefault() which prevented it from actually adding
pages to the pmap.
* Remove ancient dead debugging code.
* Add DDB commands for examining translation registers and region
registers.
The first change fixes the 'free/cache page %p was dirty' panic which I
have been seeing when the system is put under moderate load. It also
fixes the negative RSS values in ps which have been confusing me for a
while.
With this set of changes the ia64 port is reliable enough to build its
own kernels, even with a 20-way parallel build. Next stop buildworld.