METHOD, DEVICE AND COMPUTER PROGRAM PRODUCT FOR CACHE MANAGEMENT

• US 20200133870A1
• Filed: 09/27/2019
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Inventors: Zhang, Ming, Lv, Shuo
• Granted Patent: US 11,210,228 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/0804 with main memory updating G06F12/0806 takes precedence
• CPC Class Codes: G06F 12/0864 using pseudo-associative means, e.g. set-associative or hashing
• CPC Class Codes: G06F 12/0871 Allocation or management of cache space
• CPC Class Codes: G06F 12/0882 Page mode
• CPC Class Codes: G06F 12/123 with age lists, e.g. queue, most recently used [MRU] list or least recently used [LRU] list
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0638 Organizing or formatting or addressing of data

Abstract

Techniques perform cache management. Such techniques involve: obtaining a first cache page of the cache to be flushed, the first cache page being associated with a target storage block in a storage device; determining from the cache a set of target cache pages to be flushed, each of the set of target cache pages being associated with the target storage block; and writing data in the first cache page and data in each of the set of target cache pages into the target storage block simultaneously.

Claims

1. A method of managing a cache, comprising:

obtaining a first cache page of the cache to be flushed, the first cache page being associated with a target storage block in a storage device;

determining from the cache a set of target cache pages to be flushed, each of the set of target cache pages being associated with the target storage block; and

writing data in the first cache page and data in each of the set of target cache pages into the target storage block simultaneously.

2. The method of claim 1, wherein determining the set of target cache pages comprises:

determining, based on a specific cache page in a plurality of lists of cache pages to be flushed associated with a plurality of processor cores, a set of candidate lists of cache pages from the plurality of lists of cache pages to be flushed; and

determining, from the set of candidate lists of cache pages, at least one cache page associated with the target storage block as the set of target cache pages.

3. The method of claim 2, wherein determining the set of candidate cache page lists comprises:

obtaining a second cache page with the earliest modification time in a first one of the plurality of lists of cache pages to be flushed;

determining whether the second cache page is associated with the target storage block; and

in response to determining that the second cache page is associated with the target storage block, adding the first list of cache pages to be flushed into the set of candidate lists of cache pages.

4. The method of claim 2, wherein a list of cache pages to be flushed is a First Input First Output (FIFO) queue, and wherein the specific cache page is a starting cache page at a head of the FIFO queue, and

wherein determining the set of candidate lists of cache pages comprises determining one or more candidate lists of cache pages from the plurality of lists of cache pages to be flushed, the starting cache page of a candidate list of cache pages being associated with the target storage block.

5. The method of claim 4, wherein determining the at least one cache page from the set of candidate lists of cache pages comprises:

for a second one of the set of candidate lists of cache pages, determining relevance of cache pages in the second list with the target storage block sequentially in an order of the list until finding an unrelated cache page; and

adding cache pages associated with the target storage block into the set of target cache pages.

6. The method of claim 1, wherein determining the set of target cache pages to be flushed comprises:

determining, based on the target storage block and from a hash bucket, a list of cache pages to be flushed associated with the target storage block, the hash bucket storing lists of cache pages to be flushed corresponding to different storage spaces; and

determining, from the list of cache pages to be flushed, at least one cache page associated with the target storage block as the set of target cache pages.

7. A device for managing a cache, comprising:

at least one processing unit; and

at least one memory coupled to the at least one processing unit and storing instructions for execution by the at least one processing unit, the instructions, when executed by the at least one processing unit, causing the device to perform acts comprising;

obtaining a first cache page of the cache to be flushed, the first cache page being associated with a target storage block in a storage device;

determining from the cache a set of target cache pages to be flushed, each of the set of target cache pages being associated with the target storage block; and

writing data in the first cache page and data in each of the set of target cache pages into the target storage block simultaneously.

8. The device of claim 7, wherein determining the set of target cache pages comprises:

determining, based on a specific cache page in a plurality of lists of cache pages to be flushed associated with a plurality of processor cores, a set of candidate lists of cache pages from the plurality of lists of cache pages to be flushed; and

determining, from the set of candidate lists of cache pages, at least one cache page associated with the target storage block as the set of target cache pages.

9. The device of claim 8, wherein determining the set of candidate cache page lists comprises:

obtaining a second cache page with the earliest modification time in a first one of the plurality of lists of cache pages to be flushed;

determining whether the second cache page is associated with the target storage block; and

in response to determining that the second cache page is associated with the target storage block, adding the first list of cache pages to be flushed into the set of candidate lists of cache pages.

10. The device of claim 8, wherein a list of cache pages to be flushed is a First Input First Output (FIFO) queue, and wherein the specific cache page is a starting cache page at a head of the FIFO queue, and

wherein determining the set of candidate lists of cache pages comprises determining one or more candidate lists of cache pages from the plurality of lists of cache pages to be flushed, the starting cache page of a candidate list of cache pages being associated with the target storage block.

11. The device of claim 10, wherein determining the at least one cache page from the set of candidate lists of cache pages comprises:

for a second one of the set of candidate lists of cache pages, determining relevance of cache pages in the second list with the target storage block sequentially in an order of the list until finding an unrelated cache page; and

adding cache pages associated with the target storage block into the set of target cache pages.

12. The device of claim 7, wherein determining the set of target cache pages to be flushed comprises:

determining, based on the target storage block and from a hash bucket, a list of cache pages to be flushed associated with the target storage block, the hash bucket storing lists of cache pages to be flushed corresponding to different storage spaces; and

determining, from the list of cache pages to be flushed, at least one cache page associated with the target storage block as the set of target cache pages.

13. A computer program product being stored in a non-transient computer storage medium and comprising machine-executable instructions which, when executed by a device, cause the device to perform acts comprising:

obtaining a first cache page of the cache to be flushed, the first cache page being associated with a target storage block in a storage device;

determining from the cache a set of target cache pages to be flushed, each of the set of target cache pages being associated with the target storage block; and

writing data in the first cache page and data in each of the set of target cache pages into the target storage block simultaneously.

14. The computer program product of claim 13, wherein determining the set of target cache pages comprises:

determining, based on a specific cache page in a plurality of lists of cache pages to be flushed associated with a plurality of processor cores, a set of candidate lists of cache pages from the plurality of lists of cache pages to be flushed; and

determining, from the set of candidate lists of cache pages, at least one cache page associated with the target storage block as the set of target cache pages.

15. The computer program product of claim 14, wherein determining the set of candidate cache page lists comprises:

obtaining a second cache page with the earliest modification time in a first one of the plurality of lists of cache pages to be flushed;

determining whether the second cache page is associated with the target storage block; and

in response to determining that the second cache page is associated with the target storage block, adding the first list of cache pages to be flushed into the set of candidate lists of cache pages.

16. The computer program product of claim 14, wherein a list of cache pages to be flushed is a First Input First Output (FIFO) queue, and wherein the specific cache page is a starting cache page at a head of the FIFO queue, and

wherein determining the set of candidate lists of cache pages comprises determining one or more candidate lists of cache pages from the plurality of lists of cache pages to be flushed, the starting cache page of a candidate list of cache pages being associated with the target storage block.

17. The computer program product of claim 16, wherein determining the at least one cache page from the set of lists of candidate cache pages comprises:

for a second one of the set of candidate lists of cache pages, determining relevance of cache pages in the second list with the target storage block sequentially in an order of the list until finding an unrelated cache page; and

adding cache pages associated with the target storage block into the set of target cache pages.

18. The computer program product of claim 13, wherein determining the set of target cache pages to be flushed comprises:

determining, based on the target storage block and from a hash bucket, a list of cache pages to be flushed associated with the target storage block, the hash bucket storing lists of cache pages to be flushed corresponding to different storage spaces; and

determining, from the list of cache pages to be flushed, at least one cache page associated with the target storage block as the set of target cache pages.