When using one page size only, all mappings to the same memory object are done using the same page size. With use of multiple page sizes, it is possible that one mapping may use a small page size to map a small part of a memory object, while a second mapping may use a large page size to map a large part of the same memory object. If the system is not careful, the first mapping (which uses small pages) may preclude using large pages for the second mapping