Processing flush requests by utilizing storage system write notifications

• US 9,632,711 B1
• Filed: 07/02/2014
• Issued: 04/25/2017
• Est. Priority Date: 04/07/2014
• Status: Active Grant

• Current Assignee: JP Morgan Chase Bank, N.A. (JP Morgan Chase & Co)
• Original Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Inventors: Obr, Nathan
• Primary Examiner(s): Thai, Tuan
• Assistant Examiner(s): Gossage, Glenn
• Application Number:
  US14/322,520
• Time in Patent Office: 1,028 Days
• CPC Class Codes: G06F 12/0804 with main memory updating G06F12/0806 takes precedence
• CPC Class Codes: G06F 12/0868 Data transfer between cache memory and other subsystems, e.g. storage devices or host systems
• CPC Class Codes: G06F 12/0891 using clearing, invalidating or resetting means
• CPC Class Codes: G06F 2212/1016 Performance improvement
• CPC Class Codes: G06F 2212/1056 Simplification
• CPC Class Codes: G06F 2212/313 In storage device
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

Systems and methods for utilization of notification or ordering commands are disclosed that can enable more efficient processing of flush requests from software programs and increase data consistency in storage devices. For example, when an application requests that a data cache be flushed, a computing device may—instead of completely emptying the data cache—notify the application of a successful flush once relevant data of the application has been committed to non-volatile memory. Targeted notifications, which may identify the relevant data in the data cache, can limit the scope of a flush request, such that the speed and efficiency of the command is increased relative to a non-specific full-cache flush. Such increases in efficiency of flush requests may greatly increase the speed and efficiency of storage devices, and consequently the performance of programs utilizing such storage devices.

Claims

1. A computer-implemented method to manage consistency of data in a data cache of a storage device, the computer-implemented method comprising:

receiving a request from a software program to flush the data cache;

generating a notification command that, when executed by the storage device, generates a notification indicating writing of at least one data item within the data cache to a non-volatile memory, wherein the notification command identifies the at least one data item based at least in part on an identifier of the at least one data item;

transmitting the notification command to the storage device via a communication link;

receiving the notification from the storage device; and

transmitting to the software program an indication of completion of the request to flush the data cache.

2. The computer-implemented method of claim 1, wherein the communication link is at least one of a system bus, a storage bus, or a communication network.

3. The computer-implemented method of claim 1, wherein the communication link utilizes at least one of a serial ATA (SATA) standard, advanced host controller interface (AHCI) standard, or a non-volatile memory express (NVMe) standard.

4. The computer-implemented method of claim 1, wherein the at least one data item is associated with a request to write data generated by the software program, and wherein the method further comprises:

prior to receiving the request from the software program to flush the data cache;

selecting the identifier based at least in part on the request to write data; and

transmitting the identifier and the at least one data item to the storage device.

5. The computer-implemented method of claim 4, wherein the identifier is selected based at least in part on metadata associated with the request to write data.

6. The computer-implemented method of claim 5, wherein the metadata indicates at least one of an identity of the software program, a reference location to which the at least one data item is to be written, and a pre-existing identifier of the at least one data item.

7. The computer-implemented method of claim 1, wherein the identifier is a designated identifier used to prevent writing of the at least one data item if it is determined that the request is associated with a page file.

8. The computer-implemented method of claim 1, wherein the identifier is associated with a plurality of data items within the data cache.

9. The computer-implemented method of claim 8, wherein the plurality of data items are associated with at least one of:

an individual file or the software program.

10. The computer-implemented method of claim 1, wherein the software program is at least one of:

a software application or an operating system.

11. A system comprising:

a communication interface associated with a host system and configured to transmit communications between the host system and a storage system; and

a processor associated with the host system and configured with specific computer-executable instructions that, when executed by the processor, cause the processor to;

receive a request from a software program to flush a data cache of the storage system;

generate a notification command that, when executed by the storage system, generates a notification indicating writing of at least one data item within the data cache to a non-volatile memory of the storage system, wherein the notification command identifies the at least one data item based at least in part on an identifier of the at least one data item;

transmit the notification command to the storage system via the communication interface;

receive the notification from the storage system; and

transmit to the software program an indication of completion of the request to flush the data cache.

12. The system of claim 11, wherein the at least one data item is associated with a request to write data generated by the software program, and wherein the computer-executable instructions further cause the processor to:

prior to reception of the request from the software program to flush the data cache;

select the identifier based at least in part on the request to write data;

transmit the identifier to the storage system; and

transmit the at least one data item to the storage system for storage in the data cache.

13. The system of claim 12, wherein the identifier is selected based at least in part on metadata associated with the request to write data.

14. The system of claim 13, wherein the metadata indicates at least one of an identity of the software program, a location to which the at least one data item is to be written, or a pre-existing identifier of the at least one data item.

15. The system of claim 11, wherein the identifier is a designated identifier used to prevent writing of the at least one data item if it is determined that the request is associated with a page file.

16. The system of claim 11, wherein the identifier is associated with a plurality of data items within the data cache.

17. The system of claim 16, wherein the plurality of data items are associated with at least one of:

an individual file or the software program.

18. A non-transitory computer-readable medium including computer-executable instructions that, when executed by a computing device, cause the computing device to:

receive a request from a software program to flush a data cache of a storage system;

generate a notification command that, when executed by the storage system, generates a notification indicating writing of at least one data item within the data cache to a non-volatile memory, wherein the notification command identifies the at least one data item based at least in part on an identifier of the at least one data item;

transmit the notification command to the storage system via a communication interface;

receive the notification from the storage system; and

transmit to the software program an indication of completion of the request to flush the data cache.

19. The non-transitory computer-readable medium of claim 18, wherein the at least one data item is associated with a request to write data generated by the software program, and wherein the computer-executable instructions further cause the computing device to:

prior to reception of the request from the software program to flush the data cache;

select the identifier based at least in part on the request to write data;

transmit the identifier to the storage system; and

transmit the at least one data item to the storage system for storage in the data cache.

20. The non-transitory computer-readable medium of claim 19, wherein the identifier is selected based at least in part on metadata associated with the request to write data.

21. The non-transitory computer-readable medium of claim 20, wherein the metadata indicates at least one of an identity of the software program, a location to which the at least one data item is to be written, or—

a pre-existing identifier of the at least one data item.

22. The non-transitory computer-readable medium of claim 18, wherein the identifier is a designated identifier used to prevent writing of the at least one data item if it is determined that the request is associated with a page file.

23. The non-transitory computer-readable medium of claim 18, wherein the identifier is associated with a plurality of data items within the data cache.

24. The non-transitory computer-readable medium of claim 23 wherein the plurality of data items are associated with at least one of:

an individual file or the software program.