This is not necessary, since userland teams' page directories also
contain the kernel mappings, and avoids unnecessary TLB flushes. To make
that possible the vm_translation_map_arch_info objects are reference
counted now.
This optimization reduces the kernel time of the Haiku build on my
machine with SMP disabled a few percent, but interestingly the total
time decreases only marginally. Haven't tested with SMP yet, but for
full impact CPU affinity would be needed.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28287 a95241bf-73f2-0310-859d-f6bbb57e9c96