METHODS, SYSTEMS AND COMPUTER READABLE MEDIA FOR INTELLIGENT FETCHING OF DATA STORAGE DEVICE COMMANDS FROM SUBMISSION QUEUES

• US 20170090753A1
• Filed: 09/28/2015
• Published: 03/30/2017
• Est. Priority Date: 09/28/2015
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Inventors: Harari Shechter, Noga, Benisty, Shay, Segev, Amir, Sharifie, Tal
• Granted Patent: US 9,927,983 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0653 Monitoring storage devices or systems
• 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]
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays

Abstract

Methods, systems, and computer readable media for intelligent fetching of storage device commands from submission queues are disclosed. On method is implemented in a data storage device including a controller and a memory. The method includes collecting submission queue command statistics; monitoring resource state of the data storage device. The method further includes using the submission queue command statistics and the resource state to select a submission queue from which a next data storage device command should be fetched. The method further includes fetching the command from the selected submission queue. The method further includes providing the command to command processing logic.

Claims

1. In a data storage device including a controller and a memory, a method for intelligent submission queue command fetching, the method comprising:

collecting submission queue command statistics;

monitoring resource state of the data storage device;

using the submission queue command statistics and the resource state to select a submission queue from which a next data storage device command should be fetched;

fetching the command from the selected submission queue; and

providing the command to command processing logic.

2. The method of claim 1 wherein collecting submission queue command statistics includes collecting statistics regarding a number of pending commands in each of a plurality of submission queues.

3. The method of claim 1 wherein collecting submission queue command statistics includes collecting an indication of a number of commands fetched from each of a plurality of submission queues.

4. The method of claim 1 wherein collecting submission queue command statistics includes collecting command type information for each of a plurality of submission queues.

5. The method of claim 4 wherein collecting command type information includes collecting information regarding whether particular submission queues historically contain a majority of read or a majority of write commands.

6. The method of claim 4 wherein collecting command type information includes collecting information regarding whether particular submission queues historically contain a majority of random input/output (I/O) commands or a majority of sequential I/O commands.

7. The method of claim 1 wherein monitoring resource state includes monitoring read pipeline state of the data storage device.

8. The method of claim 1 wherein monitoring resource state includes monitoring write pipeline state of the data storage device.

9. The method of claim 1 wherein using the submission queue command statistics and the resource state to select the submission queue includes, in response to determining that a read pipeline of the data storage device is currently unavailable to process a read command and that a particular submission queue has historically contained a majority of read commands, bypassing selection of the particular submission queue in favor of a submission queue that has historically contained a majority of write commands.

10. The method of claim 1 wherein using the submission queue command statistics and the resource state to select the submission queue includes, in response to determining that a write pipeline of the data storage device is currently unavailable to process a write command and that a particular submission queue has historically contained a majority of write commands, bypassing selection of the particular submission queue in favor of a submission queue that has historically contained a majority of read commands.

11. The method of claim 1 wherein collecting the submission queue command statistics and monitoring the resource state includes continually collecting the submission queue command statistics and continually monitoring the resource state.

12. The method of claim 1 comprising initially operating in a static submission queue selection mode and switching to using the submission queue command statistics and the resource state to select the submission queue from which the next data storage device command should be fetched in response to a predetermined trigger.

13. The method of claim 1 wherein the data storage device comprises a nonvolatile memory device and the controller comprises a nonvolatile memory controller.

14. The method of claim 13 wherein the nonvolatile memory controller comprises a nonvolatile memory express (NVMe) controller.

15. The method of claim 1 wherein the memory comprises two dimensional or three dimensional NAND flash memory.

16. A data storage device comprising:

a memory;

a command monitor for collecting submission queue command statistics;

a resource monitor for monitoring resource state of the data storage device;

a submission queue selector for using the submission queue command statistics and the resource state to select a submission queue from which a next data storage device command should be fetched; and

a command fetcher for fetching the command from the selected submission queue and providing the command to the submission queue selector, which provides the command to command processing logic.

17. The data storage device of claim 16 wherein the command monitor is configured to collect statistics regarding a number of pending commands in each of a plurality of submission queues.

18. The data storage device of claim 16 wherein the command monitor is configured to collect an indication of a number of commands fetched from each of a plurality of submission queues.

19. The data storage device of claim 16 wherein the command monitor is configured to collect command type information for each of a plurality of submission queues.

20. The data storage device of claim 19 wherein the command monitor is configured to collect information regarding whether particular submission queues have historically contained a majority of read commands or a majority of write commands.

21. The data storage device of claim 19 wherein the command monitor is configured to collect information regarding whether particular submission queues have historically contained a majority of random input/output (I/O) commands or a majority of sequential I/O commands.

22. The data storage device of claim 16 wherein the resource monitor is configured to monitor read pipeline state of the data storage device.

23. The data storage device of claim 16 wherein the resource monitor is configured to monitor write pipeline state of the data storage device.

24. The data storage device of claim 16 wherein the submission queue selector is configured to, in response to a determination that a read pipeline of the data storage device is currently unavailable to process a read command and that a particular submission queue has historically contained a majority of read commands, bypass selection of the particular submission queue in favor of a submission queue that has historically contained a majority of write commands.

25. The data storage device of claim 16 wherein the submission queue selector is configured to, in response to a determination that a write pipeline of the data storage device is currently unavailable to process a write command and that a particular submission queue has historically contained a majority of write commands, bypass selection of the particular submission queue in favor of a submission queue that has historically contained a majority of read commands.

26. The system of claim 16 wherein the command monitor is configured to continually collect the submission queue command statistics and wherein the resource monitor is configured to continually monitor the resource state of the data storage device.

27. The system of claim 16 wherein the submission queue selector is configured to initially operate in a static submission queue selection mode and switch to using the submission queue command statistics and the resource state to select the submission queue from which the next data storage device command should be fetched in response to a predetermined trigger.

28. The data storage device of claim 16 comprising a controller, wherein the command monitor, the resource monitor, the submission queue selector, and the command fetcher are components of the controller.

29. The data storage device of claim 16 wherein the memory comprises a nonvolatile memory and further comprising a memory controller.

30. The data storage device of claim 29 wherein the memory controller comprises a nonvolatile memory controller.

31. The data storage device of claim 30 wherein the nonvolatile memory controller comprises a nonvolatile memory express (NVMe) controller.

32. The data storage device of claim 16 wherein the memory comprises two dimensional or three dimensional NAND flash memory.

33. A non-transitory computer readable medium having stored thereon executable instructions that when executed by the processor of a computer control the computer to perform steps comprising:

collecting submission queue command statistics;

monitoring resource state of a data storage device including a memory and a controller;

using the submission queue command statistics and the resource state to select a submission queue from which a next data storage device command should be fetched;

fetching the command from the selected submission queue; and

providing the command to command processing logic.