Intelligent cache management

• US 8,127,088 B2
• Filed: 01/27/2005
• Issued: 02/28/2012
• Est. Priority Date: 01/27/2005
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Kolovson, Curt
• Primary Examiner(s): Ellis, Kevin
• Assistant Examiner(s): Cygiel, Gary W
• Application Number:
  US11/044,962
• Publication Number:
  US 20060168403A1
• Time in Patent Office: 2,588 Days
• Field of Search: 711/141
• US Class Current: 711/154
• CPC Class Codes: G06F 12/0804 with main memory updating G06F12/0806 takes precedence
• CPC Class Codes: G06F 12/0862 with prefetch
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 12/126 with special data handling, e.g. priority of data or instructions, handling errors or pinning
• CPC Class Codes: G06F 2212/6028 Prefetching based on hints or prefetch instructions
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

An exemplary storage network, storage controller, and methods of operation are disclosed. In one embodiment, a method of managing cache memory in a storage controller comprises receiving, at the storage controller, a cache hint generated by an application executing on a remote processor, wherein the cache hint identifies a memory block managed by the storage controller, and managing a cache memory operation for data associated with the memory block in response to the cache hint received by the storage controller.

Claims

1. A method of managing cache memory in a storage controller, comprising:

receiving, at the storage controller, a data operation request;

parsing the data operation request to extract a cache hint from a header in the data operation request, wherein the cache hint is generated by one of a plurality of modules in a software stack executing on a remote processor, and the cache hint identifies a memory block managed by the storage controller;

wherein the cache hint generated by the one of the plurality of modules is selected from a group comprising a Write Through cache hint, a Pin cache hint, an Unpin cache hint, a Sequential scan cache hint, a Priority Cache hint, and a Working Set cache hint; and

managing a cache memory operation for data associated with the memory block in response to the cache hint received by the storage controller;

wherein the cache hint generated by a first module in the software stack is analyzed by a second module in the software stack to determine whether the cache hint conflicts with the second module.

2. The method of claim 1, wherein:

the cache hint comprises the Write Through cache hint; and

managing the cache memory operation comprises executing a fast de-stage operation on one or more data blocks identified in the cache hint.

3. The method of claim 1, wherein:

the cache hint comprises the Pin cache hint; and

managing a cache memory operation comprises holding one or more data blocks identified in the Pin cache hint until an Unpin cache hint identifying the one or more data blocks is received by the controller.

4. The method of claim 1, wherein:

the cache hint comprises the Pin cache hint; and

managing a cache memory operation comprises holding one or more data blocks identified in the Pin cache hint until a time threshold expires.

5. The method of claim 1, wherein:

the cache hint comprises the Pin cache hint; and

managing a cache memory operation comprises holding one or more data blocks identified in the Pin cache hint until a capacity threshold is reached.

6. The method of claim 1, wherein:

the cache hint comprises the Sequential Scan cache hint; and

managing a cache memory operation comprises pre-fetching from a permanent storage medium one or more data blocks identified in the Sequential Scan cache hint.

7. The method of claim 1, wherein:

the storage controller maintains a queue of data blocks for executing cache operations;

the cache hint comprises the Priority cache hint, wherein the Priority cache hint associates a priority level for cache operations associated with one or more data blocks identified in the cache hint; and

the storage controller organizes data blocks in the queue in accordance with the priority level.

8. The method of claim 1, wherein:

the storage controller maintains logical associations for working sets of data blocks for executing cache operations;

the cache hint comprises the Working Set cache hint, wherein the Working Set cache hint identifies a working set for cache operations associated with one or more data blocks identified in the cache hint; and

the storage controller manages the data blocks identified in the cache hint as part of the working set identified in the cache hint.

9. The method of claim 1, wherein the plurality of modules of the software stack comprise at least two of an application software, a database management software, a file management system, and an operating system.

10. A storage controller, comprising:

an input port to receive a data operation request from a remote computing device;

a processor; and

a memory module,

wherein the memory module comprises logic instructions which, when executed, configure the processor to;

parse the data operation request to extract a cache hint from a header in the data operation request, wherein the cache hint is generated by one of a plurality of modules in a software stack executing on a remote computing device, and the cache hint identifies a memory block managed by the storage controller;

wherein the cache hint generated by the one of the plurality of modules is selected from a group comprising a Write Through cache hint, a Pin cache hint, an Unpin cache hint, a Sequential scan cache hint, a Priority Cache hint, and a Working Set cache hint; and

manage a cache memory operation for data associated with the memory block in response to the cache hint received by the storage controller;

wherein the cache hint generated by a first module in the software stack is analyzed by a second module in the software stack to determine whether the cache hint conflicts with the second module.

11. The storage controller of claim 10, wherein:

the cache hint comprises the Write Through cache hint; and

the storage controller executes a fast de-stage operation on one or more data blocks identified in the cache hint.

12. The storage controller of claim 10, wherein:

the cache hint comprises the Pin cache hint; and

the storage controller holds one or more data blocks identified in the Pin cache hint until an Unpin cache hint identifying the one or more data blocks is received by the controller.

13. The storage controller of claim 10, wherein:

the cache hint comprises the Pin cache hint; and

the storage controller holds one or more data blocks identified in the Pin cache hint until a time threshold expires.

14. The storage controller of claim 10, wherein:

the cache hint comprises the Pin cache hint; and

the storage controller holds one or more data blocks identified in the Pin cache hint until a capacity threshold is reached.

15. The storage controller of claim 10, wherein:

the cache hint comprises the Sequential Scan cache hint; and

the storage controller pre-fetches from a permanent storage medium one or more data blocks identified in the Sequential Scan cache hint.

16. The storage controller of claim 10, wherein:

the storage controller maintains a queue of data blocks for executing cache operations;

the cache hint comprises the Priority cache hint, wherein the Priority cache hint associates a priority level for cache operations associated with one or more data blocks identified in the cache hint; and

the storage controller organizes data blocks in the queue in accordance with the priority level.

17. The storage controller of claim 10, wherein:

the storage controller maintains logical associations for working sets of data blocks for executing cache operations;

the cache hint comprises the Working Set cache hint, wherein the Working Set cache hint identifies a working set for cache operations associated with one or more data blocks identified in the cache hint; and

the storage controller manages the data blocks identified in the cache hint as part of the Working Set identified in the cache hint.

18. The storage controller of claim 10, wherein the plurality of modules of the software stack comprise at least two of an application software, a database management software, a file management system, and an operating system.

19. A storage device, comprising:

at least one disk drive;

a controller to manage data input/output operations between the disk drive and a remote processor; and

a cache memory module communicatively connected to the controller,

wherein the controller receives a data operation request and parses the data operation request to extract a cache hint from a header in the data operation request, wherein the cache hint is generated by one of a plurality of modules in a software stack executing on a remote computing device and manages data operations in the cache memory based on the cache hint received by the controller;

wherein the cache hint generated by the one of the plurality of modules is selected from a group comprising a Write Through cache hint, a Pin cache hint, an Unpin cache hint, a Sequential scan cache hint, a Priority Cache hint, and a Working Set cache hint; and

wherein the cache hint generated by a first module in the software stack is analyzed by a second module in the software stack to determine whether the cache hint conflicts with the second module.

20. The storage device of claim 19, wherein:

the cache hint comprises the Write Through cache hint; and

the controller executes a fast de-stage operation on one or more data blocks identified in the cache hint.

21. The storage device of claim 19, wherein:

the cache hint comprises the Pin cache hint; and

the controller holds one or more data blocks identified in the Pin cache hint until a time threshold expires.

22. The storage device of claim 19, wherein:

the cache hint comprises the Pin cache hint; and

the controller holds one or more data blocks identified in the Pin cache hint until a capacity threshold is reached.

23. The storage device of claim 19, wherein:

the cache hint comprises the Sequential Scan cache hint; and

managing a cache memory operation comprises pre-fetching from a permanent storage medium one or more data blocks identified in the Sequential Scan cache hint.

24. The storage device of claim 19, wherein:

the storage controller maintains a queue of data blocks for executing cache operations;

the cache hint comprises the Priority cache hint, wherein the Priority cache hint associates a priority level for cache operations associated with one or more data blocks identified in the cache hint; and

the storage controller organizes data blocks in the queue in accordance with the priority level.

25. The storage device of claim 19, wherein the plurality of modules of the software stack comprise at least two of an application software, a database management software, a file management system, and an operating system.