Selective memory donation in virtual real memory environment

A computer usable program product comprising a computer usable hardware storage device including computer usable code for selective memory donation, the computer usable code comprising

• computer usable code for receiving, in a virtual machine, a request for memory donation;
• computer usable code for selectively determining with an available option to ignore the request, in the virtual machine, whether a size of a portion of a memory space being used for file caching exceeds a threshold size, forming a threshold determination, the portion of the memory space being used for file caching forming a file cache;
• computer usable code for releasing, responsive to the threshold determination being true, a part of the file cache that exceeds the threshold size, the part forming a released file cache;
• and
• computer usable code for making available, responsive to the request, the released file cache to a requestor of the request by making a set of virtualized real memory addresses corresponding to the released file cache accessible to the requestor, wherein the set of virtualized real memory addresses remains accessible to the virtual machine to reclaim at least a portion of the released file cache.

A data processing system for selective memory donation, the data processing system comprising:

• a storage device including a storage medium, wherein the storage device stores computer usable program code;
• and
• a processor, wherein the processor executes the computer usable program code, and wherein the computer usable program code comprises:
• computer usable code for receiving, in a virtual machine, a request for memory donation;
• computer usable code for selectively determining with an available option to ignore the request, in the virtual machine, whether a size of a portion of a memory space being used for file caching exceeds a threshold size, forming a threshold determination, the portion of the memory space being used for file caching forming a file cache;
• computer usable code for releasing, responsive to the threshold determination being true, a part of the file cache that exceeds the threshold size, the part forming a released file cache;
• and
• computer usable code for making available, responsive to the request, the released file cache to a requestor of the request by making a set of virtualized real memory addresses corresponding to the released file cache accessible to the requestor, wherein the set of virtualized real memory addresses remains accessible to the virtual machine to reclaim at least a portion of the released file cache.