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US 7,487,320 B2Granted
Apparatus and system for dynamically allocating main memory among a plurality of applications
AssigneeInternational Business Machines Corporation
InventorsSorav Bansal, Paul Edward McKenney, Dharmendra Shantilal Modha
Life of this patent
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Abstract
An apparatus and system are disclosed for dynamically allocating main memory among applications. The apparatus includes a cache memory module configured to maintain a first list and a second list, each list having a plurality of pages, and a resize module configured to resize the cache by adaptively selecting the first or second list and subtracting pages from or adding pages to the selected list. The system includes the apparatus and a cache replacement module configured to adaptively distribute a workload between the first list and the second list.
Claims13
An apparatus to dynamically allocate main memory among a plurality of virtual operating systems, the apparatus comprising:
- a cache memory module comprising an allocation of very large scale integration random access memory circuits for a virtual operating system, the cache memory module maintaining at least a first list and a second list, each list configured to store a plurality of pages, the first list containing pages requested only once since a last removal of a page from the first list and the second list containing pages requested at least twice since a last removal of pages from the second list, each list having a T portion and a B portion, the cache memory module having an allocation of pages;
- and
- a resize module comprising computer instructions stored in a memory device, executing on a processor, that shrinks the allocation of the cache memory module by setting a size of the T portion of the first list to a new allocation, discarding pages from the T portions of the first and second lists until a sum of sizes of the T portions of the first and second lists is less than the new allocation, and if a sum of sizes of the T and B portions of the first list is greater than the new allocation, removing pages from the B portion of the first list until a sum of sizes of the B portions of the first and second lists is less than the new allocation else removing pages from the B portion of the second list until the sum of the sizes of the B portions of the first and second lists is less than the new allocation.
A system to dynamically allocate main memory among a plurality of virtual operating systems, the apparatus comprising:
- a cache memory module comprising an allocation of very large scale integration random access memory circuits for a virtual operating system, the cache memory module maintaining a first list and a second list, each list configured to store a plurality of pages, the first list containing pages requested only once since a last removal of a page from the first list and the second list containing pages requested at least twice since a last removal of pages from the second list, each list having a T portion and a B portion, the cache memory module having an allocation of pages;
- and
- a cache replacement module comprising very large scale integration circuits and configured to adaptively distribute a workload between the first list and the second list;
- and
- a resize module comprising computer instructions stored in a memory device, executing on a processor, that shrinks the allocation of the cache memory module by setting a size of the T portion of the first list to a new allocation, discarding pages from the T portions of the first and second lists until a sum of sizes of the T portions of the first and second lists is less than the new allocation, and if a sum of sizes of the T and B portions of the first list is greater than the new allocation, removing pages from the B portion of the first list until a sum of sizes of the B portions of the first and second lists is less than the new allocation else removing pages from the B portion of the second list until the sum of the sizes of the B portions of the first and second lists is less than the new allocation.
2 more elements
A program of machine-readable instructions stored in a memory device and executable by a digital processing apparatus to perform an operation to dynamically allocate main memory among a plurality of virtual operating systems, the operation comprising:
- maintaining at least a first list and a second list, each list configured to store a plurality of pages, wherein the first list containing pages requested only once since a last removal of a page from the first list and the second list containing pages requested at least twice since a last removal of pages from the second list and each list comprises a T portion and a B portion;
- maintaining a cache memory module allocated to the virtual operating system and having an allocation of pages;
- and
- shrinking the allocation by setting a size of the T portion of the first list to a new allocation, discarding pages from the T portions of the first and second lists until a sum of sizes of the T portions of the first and second lists is less than the new allocation, and if a sum of sizes of the T and B portions of the first list is greater than the new allocation, removing pages from the B portion of the first list until a sum of sizes of the B portions of the first and second lists is less than the new allocation else removing pages from the B portion of the second list until the sum of the sizes of the B portions of the first and second lists is less than the new allocation.
1 more element
An apparatus to dynamically allocate main memory among a plurality of virtual operating systems, the apparatus comprising:
- means for maintaining at least a first list and a second list, wherein the first list containing pages requested only once since a last removal of a page from the first list and the second list containing pages requested at least twice since a last removal of pages from the second list, the list maintaining means comprising very large scale integration circuits, each list configured to store a plurality of pages and having a T portion and a B portion;
- means for maintaining at least one cache memory module allocated to a virtual operating system and having an allocation of pages, the cache maintaining means comprising very large scale integration circuits;
- and
- means for resizing the allocation by shrinking the allocation of the cache memory module by setting a size of the T portion of the first list to a new allocation, discarding pages from the T portions of the first and second lists until a sum of sizes of the T portions of the first and second lists is less than the new allocation, and if a sum of sizes of the T and B portions of the first list is greater than the new allocation, removing pages from the B portion of the first list until a sum of sizes of the B portions of the first and second lists is less than the new allocation else removing pages from the B portion of the second list until the sum of the sizes of the B portions of the first and second lists is less than the new allocation, the resizing means comprising computer instructions stored in a memory device and executing on a processor.
1 more element
Dependencies are inferred from the claim text.