It is possible to boot a Unisys ES7000 with CPUs from multiple cells, and not
also include the memory from those cells. This can create a scenario where
node 0 has cpus, but no associated memory. The system will boot fine in a
configuration where node 0 has memory, but nodes 2 and 3 do not.
[AK: I rechecked the code and generic code seems to indeed handle that already.
Dan's original patch had a change for mm/slab.c that seems to be already in now.]