On Mar 8, 2005, at 5:01 PM, Toru Nishimura wrote:

> VPT for 40bit address space is considered less practical.  NetBSD/alpha
> takes a mixed strategy, doesn't it?

VPT is used by the PALcode to service TLB misses.  It is very 
efficient, and I suggest using it for the TLB miss path with your new 
pmap.

The Alpha pmap does use a 3-level table in the pmap module itself, and 
uses KSEG to access those pages.  That could prove a bad strategy with 
MIPS, since you could end up with incompatible virtual aliases (KSEG 
address vs. VPT address).

-- thorpej