92efaa3886
on the Itanium2 system I have when we use up *all* of the initial 256MB direct mapped region before we are ready to dynamically expand it. The machine that I have has 4 cpus and a very big hole in the middle. This makes the bogus '(last_address - first_address) / PAGE_SIZE' calculations especially dangerous and caused many millions of initial PV/PTE's to be preallocated.