Method and apparatus for managing memory for dynamic promotion of virtual memory page sizes

An apparatus comprising:

• a real memory;
• and
• an operating system, wherein the operating system reserves a contiguous range of real memory to form a reservation within a plurality of reservations for the real memory in response to a request for a page to be moved into the real memory, wherein the page only occupies a portion of the contiguous range of real memory for the reservation;
• monitors the real memory to determine whether an amount of free real memory present is less than a threshold;
• and releases the selected reservation within the plurality of reservations based on an age of the selected reservation within the plurality of reservations in response to the amount of free memory being less than the threshold.

A computer program product comprising:

• a computer usable medium having computer usable program code for managing real memory, the computer implemented method comprising:
• computer usable program code, responsive to a request for a page to be moved into real memory, for reserving a contiguous range of real memory for the page corresponding to a contiguous virtual memory range to form a reservation within a plurality of reservations for the real memory, wherein the page only occupies a portion of the contiguous range of real memory for the reservation;
• and
• computer usable program code, responsive to a need for the real memory, for releasing a selected reservation within the plurality of reservations based on an age of the selected reservation within the plurality of reservations.

A data processing system comprising:

• a bus;
• a communications unit connected to the bus;
• a storage device connected to the bus, wherein the storage device includes computer usable program code;
• and
• a processor unit connected to the bus, wherein the processor unit executes the computer usable program code to reserve a contiguous range of real memory for a page corresponding to a contiguous virtual memory range to form a reservation within a plurality of reservations for the real memory, in which the page only occupies a portion of the contiguous range of the real memory for the reservation in response to a request for the page to be moved into the real memory and release a selected reservation within the plurality of reservations based on an age of the selected reservation within the plurality of reservations in response to a need for the real memory.