METHOD AND SYSTEM FOR DISTRIBUTING TIERED CACHE PROCESSING ACROSS MULTIPLE PROCESSORS

• US 20130132674A1
• Filed: 11/21/2011
• Published: 05/23/2013
• Est. Priority Date: 11/21/2011
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: LSI Corporation (Broadcom, Inc.)
• Inventors: Sundrani, Kapil
• Granted Patent: US 9,122,606 B2
• Time in Patent Office: Days
• US Class Current: 711/122
• 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 12/0875 with dedicated cache, e.g. instruction or stack
• CPC Class Codes: G06F 2212/214 Solid state disk

Abstract

A data storage system having at least one cache and at least two processors balances the load of data access operations by directing certain processes in each data access operation to one of the processors. Each processor may be optimized for its specific processes. One processor may be dedicated to receiving and servicing data access requests; another processor may be dedicated to background tasks and cache management.

Claims

1. A data storage system comprising:

a first processor;

a second processor connected to the first processor;

a cache connected to the first processor and the second processor; and

a data storage device connected to the first processor and the second processor,

wherein;

the first processor is configured to;

receive a data write request;

write data to the cache; and

send a signal the second processor; and

the second processor is configured to;

receive a signal from the first processor; and

flush data from the cache to the data storage device.

2. The data storage device of claim 1, wherein the second processor is further configured to perform background tasks.

3. The data storage device of claim 1, wherein the second processor is further configured to periodically flush the cache to the data storage device.

4. The data storage device of claim 1, wherein the first processor is further configured to acquire a region lock on a region of the cache to prevent access to data.

5. The data storage device of claim 1, wherein the second processor is further configured to acquire a region lock on a region of the data storage device.

6. The data storage device of claim 1, further comprising a third processor connected to the first processor and the second processor, wherein:

the cache is a tiered cache comprising a first cache tier and a second cache tier; and

the third processor is configured to;

read hot spot metadata; and

transfer data from the first cache tier to the second cache tier.

7. A data storage system comprising:

a first processor;

a second processor connected to the first processor;

a cache connected to the first processor and the second processor; and

a data storage device connected to the first processor and the second processor,

wherein;

the first processor is configured to;

receive a data read request;

update hot spot metadata associated with data referenced by the data read request; and

send a signal the second processor; and

the second processor is configured to;

receive a signal from the first processor;

read the hot spot metadata associated with data referenced by the data read request; and

prefetch data referenced by the data read request from the data storage device to the cache.

8. The data storage device of claim 7, wherein the second processor is further configured to perform background tasks.

9. The data storage device of claim 7, wherein the second processor is further configured to periodically flush the cache to the data storage device.

10. The data storage device of claim 7, wherein the first processor is further configured to acquire a region lock on a region of the cache.

11. The data storage device of claim 7, wherein the second processor is further configured to acquire a region lock on a region of the data storage device.

12. The data storage device of claim 7, wherein the cache is a tiered cache comprising a first cache tier and a second cache tier.

13. The data storage device of claim 12, further comprising a third processor connected to the first processor and the second processor, wherein the third processor is configured to:

read hot spot metadata; and

transfer data from the first cache tier to the second cache tier.

14. The data storage device of claim 7, wherein the data storage device is a tiered storage device comprising a first storage tier and a second storage tier.

15. The data storage device of claim 12, further comprising a third processor connected to the first processor and the second processor, wherein the third processor is configured to:

read hot spot metadata; and

transfer data from the first storage tier to the second storage tier.

16. A method for load balancing data access transactions in a data storage system comprising a first processor, a second processor, a cache and a data storage device, such method comprising:

receiving a data access request with the first processor;

accessing data stored in the cache with the first processor;

signaling the second processor with the first processor; and

accessing data stored on the data storage device with the second processor.

17. The method of claim 16, further comprising updating hot spot metadata with the first processor.

18. The method of claim 17, further comprising prefetching data from the data storage device to the cache with the second processor.

19. The method of claim 17, further comprising prefetching data from the data storage device to the cache with a third processor.

20. The method of claim 16, wherein:

the data access request is a write operation;

signaling the second processor with the first processor comprises signaling the second processor that a flush operation is required; and

accessing data stored on the data storage device with the second processor comprises flushing data from the cache to the data storage device.