A computer implemented method, apparatus, and computer usable program code
for managing real memory. In response to a request for a page to be moved
into real memory, a contiguous range of real memory is reserved for the
page corresponding to a contiguous virtual memory range to form a
reservation within a plurality of reservations for the real memory. This
reservation enables efficient promotion of pages to a larger page size.
The page only occupies a portion of the contiguous range of real memory
for the reservation. In response to a need for real memory, a selected
reservation is released within the plurality of reservations based on an
age of the selected reservation within the plurality of reservations.