In a virtual memory system, address translation information is provided using a cluster that is associated with some range of virtual addresses and that can be used to translate any virtual address in its range to a physical address, where the sizes of the ranges mapped by different clusters may be different....http://www.google.com.au/patents/US7386697?utm_source=gb-gplus-sharePatent US7386697 - Memory management for virtual address space with translation units of variable range size
