than ascending order in vm_phys_alloc_contig() so that, for example, a
sequence of contigmalloc(low=0, high=4GB) calls doesn't exhaust the supply
of low physical memory resulting in a later contigmalloc(low=0, high=1MB)
failure.
Reported by: cy
Tested by: cy
Sponsored by: EMC / Isilon Storage Division