METHOD FOR PRIORITIZING VIRTUAL REAL MEMORY PAGING BASED ON DISK CAPABILITIES

• US 20110153975A1
• Filed: 12/17/2009
• Published: 06/23/2011
• Est. Priority Date: 12/17/2009
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Olszewski, Bret R., Michel, Dirk, Accapadi, Mathew
• Granted Patent: US 8,359,449 B2
• Time in Patent Office: Days
• US Class Current: 711/170
• CPC Class Codes: G06F 12/023 Free address space management
• CPC Class Codes: G06F 12/08 in hierarchically structured memory systems, e.g. virtual memory systems
• CPC Class Codes: G06F 2212/152 Virtualized environment, e.g. logically partitioned system

Abstract

A method manages memory paging operations. Responsive to a request to page out a memory page from a shared memory pool, the method identifies whether a physical space within one of a number of paging space devices has been allocated for the memory page. If physical space within the paging space device has not been allocated for the memory page, a page priority indicator for the memory page is identified. The memory page is then allocated to one of a number of memory pools within one of the number of paging space devices. The memory page is allocated one of the memory pools according to the page priority indicator of the memory page. The memory page is then written to the allocated memory pools.

Claims

1. A computer implemented method for managing memory paging operations, the computer implemented method comprising:

responsive to a request to page out a memory page from a shared memory pool identifying whether a physical space within one of a number of paging space devices has been allocated for the memory page;

responsive to determining that the physical space within the paging space device has not been allocated for the memory page, identifying a page priority indicator for the memory page;

responsive to identifying a page priority indicator for the memory page, allocating the memory page to one of a number of memory pools within one of the number of paging space devices, wherein the memory page is allocated to the one of the number of memory pools according to the page priority indicator of the memory page; and

responsive to allocating the memory page to one of a number of memory pools within one of the number of paging space devices, writing the memory page to the one of the number of memory pools.

2. The computer implemented method of claim 1, wherein the number of paging space devices is selected from the group consisting of physical memory, disk based memory, and combinations thereof, and wherein the step of allocating the memory page to one of the number of memory pools further comprises:

allocating the memory page to one of the number of memory pools according to the page priority indicator of the memory page and according to access times for the number of memory pools.

3. The computer implemented method of claim 1, further comprising:

responsive to identifying that the physical space within the paging space device has been allocated for the memory page, identifying the page priority indicator for the memory page and the physical space;

identifying whether the page priority indicator for the memory page is consistent with the physical space within the paging space device that has been allocated for the memory page;

responsive to identifying that the page priority indicator for the memory page is not consistent with the physical space within the paging space device that has been allocated for the memory page, deallocating the physical space within the paging space device that has been allocated for the memory page;

allocating the memory page to a second one of the number of memory pools within one of the number of paging space devices, wherein the memory page is allocated to the second one of the number of memory pools according to the page priority indicator of the memory page; and

responsive to allocating the memory page to the second one of the number of memory pools within one of the number of paging space devices, writing the memory page to the second one of the number of memory pools.

4. The computer implemented method of claim 1, wherein the step of allocating the memory page to one of the number of memory pools within one of the number of paging space devices further comprises:

allocating the memory page to one of the number of memory pools within a faster-accessing one of the number of paging space devices if the page priority indicator indicates the memory page is a high priority memory page; and

allocating the memory page to one of the number of memory pools within a slower-accessing one of the number of paging space devices if the page priority indicator indicates the memory page is a low priority memory page.

5. The computer implemented method of claim 1, wherein the step of identifying whether the physical space within one of the number of paging space devices has been allocated for the memory page further comprises:

responsive to receiving a request to page out a memory page from the shared memory pool of a logically partitioned platform, identifying whether the physical space within one of the number of paging space devices has been allocated for the memory page, wherein each of the number of shared memory partitions within the logically partitioned platform can access only a portion of the shared memory pool that is allocated to that one of the number of shared memory partitions.

6. The computer implemented method of claim 1, wherein the memory page is a first memory page, the method further comprising:

receiving a request to access a second memory page;

responsive to receiving the request to access the second memory page, requesting to page out the first memory page from the shared memory pool.

7. The computer implemented method of claim 1, further comprising:

responsive to the request to page out the memory page from the shared memory pool, identifying whether the physical space within one of the number of paging space devices has been allocated for the memory page, wherein the memory page has been allocated the physical space if the memory page is mapped to the physical space within a paging data structure;

responsive to determining that the physical space within the paging space device has not been allocated for the memory page, identifying the page priority indicator for the memory page from the paging data structure;

responsive to identifying the page priority indicator for the memory page, allocating the memory page to one of the number of memory pools within one of the number of paging space devices, wherein the memory page is allocated to the one of the number of memory pools according to the page priority indicator of the memory page; and

mapping the memory page to the physical space within the paging data structure.

8. A tangible computer storage medium having a computer program product encoded thereon for managing memory paging operations, the computer program product comprising:

instructions, responsive to a request to page out a memory page from a shared memory pool, for identifying whether a physical space within one of a number of paging space devices has been allocated for the memory page;

instructions, responsive to determining that the physical space within the paging space device has not been allocated for the memory page, for identifying a page priority indicator for the memory page;

instructions, responsive to identifying a page priority indicator for the memory page, for allocating the memory page to one of a number of memory pools within one of the number of paging space devices, wherein the memory page is allocated to the one of the number of memory pools according to the page priority indicator of the memory page; and

instructions, responsive to allocating the memory page to one of a number of memory pools within one of the number of paging space devices, for writing the memory page to the one of the number of memory pools.

9. The tangible computer storage medium of claim 8, wherein the number of paging space devices is selected from the group consisting of physical memory, disk based memory, and combinations thereof, and wherein the instructions for allocating the memory page to one of the number of memory pools further comprises:

instructions for allocating the memory page to one of the number of memory pools according to the page priority indicator of the memory page and according to access times for the number of memory pools.

10. The tangible computer storage medium of claim 8, further comprising:

instructions, responsive to identifying that the physical space within the paging space device has been allocated for the memory page, for identifying the page priority indicator for the memory page and the physical space;

instructions for identifying whether the page priority indicator for the memory page is consistent with the physical space within the paging space device that has been allocated for the memory page;

instructions, responsive to identifying that the page priority indicator for the memory page is not consistent with the physical space within the paging space device that has been allocated for the memory page, for deallocating the physical space within the paging space device that has been allocated for the memory page;

instructions for allocating the memory page to a second one of the number of memory pools within one of the number of paging space devices, wherein the memory page is allocated to the second one of the number of memory pools according to the page priority indicator of the memory page; and

instructions, responsive to allocating the memory page to the second one of the number of memory pools within one of the number of paging space devices, for writing the memory page to the second one of the number of memory pools.

11. The tangible computer storage medium of claim 8, wherein the instructions for allocating the memory page to one of the number of memory pools within one of the number of paging space devices further comprises:

instructions for allocating the memory page to one of the number of memory pools within a faster-accessing one of the number of paging space devices if the page priority indicator indicates the memory page is a high priority memory page; and

instructions for allocating the memory page to one of the number of memory pools within a slower-accessing one of the number of paging space devices if the page priority indicator indicates the memory page is a low priority memory page.

12. The tangible computer storage medium of claim 8, wherein the instructions for identifying whether the physical space within one of the number of paging space devices has been allocated for the memory page further comprises:

instructions, responsive to receiving a request to page out a memory page from the shared memory pool of a logically partitioned platform, for identifying whether the physical space within one of the number of paging space devices has been allocated for the memory page, wherein each of the number of shared memory partitions within the logically partitioned platform can access only a portion of the shared memory pool that is allocated to that one of the number of shared memory partitions.

13. The tangible computer storage medium of claim 8, wherein the memory page is a first memory page, the method further comprising:

instructions for receiving a request to access a second memory page;

instructions, responsive to receiving the request to access the second memory page, for requesting to page out the first memory page from the shared memory pool.

14. The tangible computer storage medium of claim 8, further comprising:

instructions, responsive to the request to page out the memory page from the shared memory pool, for identifying whether the physical space within one of the number of paging space devices has been allocated for the memory page, wherein the memory page has been allocated the physical space if the memory page is mapped to the physical space within a paging data structure;

instructions, responsive to determining that the physical space within the paging space device has not been allocated for the memory page, for identifying the page priority indicator for the memory page from the paging data structure;

instructions, responsive to identifying the page priority indicator for the memory page, for allocating the memory page to one of the number of memory pools within one of the number of paging space devices, wherein the memory page is allocated to the one of the number of memory pools according to the page priority indicator of the memory page; and

instructions for mapping the memory page to the physical space within the paging data structure.

15. A data processing system comprising:

a storage having a computer program product encoded thereon for managing memory paging operations;

a bus system connecting the memory to a processor; and

a processor, wherein the processor executes the computer usable program code;

responsive to a request to page out a memory page from a shared memory pool, to identify whether a physical space within one of a number of paging space devices has been allocated for the memory page;

responsive to determining that the physical space within the paging space device has not been allocated for the memory page, to identify a page priority indicator for the memory page;

responsive to identifying the page priority indicator for the memory page, to allocate the memory page to one of a number of memory pools within one of the number of paging space devices, wherein the memory page is allocated to the one of the number of memory pools according to the page priority indicator of the memory page; and

responsive to allocating the memory page to one of a number of memory pools within one of the number of paging space devices, to write the memory page to the one of the number of memory pools.

16. The data processing system of claim 15, wherein the number of paging space devices is selected from the group consisting of physical memory, disk based memory, and combinations thereof, and wherein the processor executing the computer usable program code to allocate the memory page to one of the number of memory pools further comprises the processor executing the computer usable program code:

to allocate the memory page to one of the number of memory pools according to the page priority indicator of the memory page and according to access times for the number of memory pools.

17. The data processing system of claim 15, wherein the processor further executes the computer usable program code:

responsive to identifying that the physical space within the paging space device has been allocated for the memory page, to identify the page priority indicator for the memory page and the physical space;

to identifying whether the page priority indicator for the memory page is consistent with the physical space within the paging space device that has been allocated for the memory page;

responsive to identifying that the page priority indicator for the memory page is not consistent with the physical space within the paging space device that has been allocated for the memory page, to deallocate the physical space within the paging space device that has been allocated for the memory page;

to allocate the memory page to a second one of the number of memory pools within one of the number of paging space devices, wherein the memory page is allocated to the second one of the number of memory pools according to the page priority indicator of the memory page; and

responsive to allocating the memory page to the second one of the number of memory pools within one of the number of paging space devices, to write the memory page to the second one of the number of memory pools.

18. The data processing system of claim 15, wherein the processor executing the computer usable program code to allocate the memory page to one of the number of memory pools within one of the number of paging space devices further comprises the processor executing the computer usable program code:

to allocate the memory page to one of the number of memory pools within a faster-accessing one of the number of paging space devices if the page priority indicator indicates the memory page is a high priority memory page; and

to allocate the memory page to one of the number of memory pools within a slower-accessing one of the number of paging space devices if the page priority indicator indicates the memory page is a low priority memory page.

19. The data processing system of claim 15, wherein the processor executing the computer usable program code to identify whether the physical space within one of the number of paging space devices has been allocated for the memory page further comprises the processor executing the computer usable program code:

responsive to receiving a request to page out a memory page from the shared memory pool of the logically partitioned platform, to identify whether the physical space within one of the number of paging space devices has been allocated for the memory page, wherein each of the number of shared memory partitions within the logically partitioned platform can access only a portion of the shared memory pool that is allocated to that one of the number of shared memory partitions.

20. The data processing system of claim 15, wherein the memory page is a first memory page, wherein the processor further executes the computer usable program code:

to receive a request to access a second memory page;

responsive to receiving the request to access the second memory page, to request to page out the first memory page from the shared memory pool.

21. The data processing system of claim 15, wherein the processor further executes the computer usable program code:

responsive to the request to page out the memory page from the shared memory pool, to identify whether the physical space within one of the number of paging space devices has been allocated for the memory page, wherein the memory page has been allocated the physical space if the memory page is mapped to the physical space within a paging data structure;

responsive to determining that the physical space within the paging space device has not been allocated for the memory page, to identify the page priority indicator for the memory page from the paging data structure;

responsive to identifying the page priority indicator for the memory page, to allocate the memory page to one of the number of memory pools within one of the number of paging space devices, wherein the memory page is allocated to the one of the number of memory pools according to the page priority indicator of the memory page; and

to map the memory page to the physical space within the paging data structure.