Implementing automatic rate control in a memory sub-system

Patent metadata

Field	Value
Publication number	US-11960740-B2
Application number	US-202218077762-A
Country	US
Kind code	B2
Filing date	Dec 8, 2022
Priority date	Jul 19, 2021
Publication date	Apr 16, 2024
Grant date	Apr 16, 2024

Abstract

A processing device in a memory system identifies a workload condition associated with a memory device. The processing device determines a host rate associated with the memory device based on the workload condition. The processing device detects a change in a condition of the memory device from a first state condition to a second state condition. The processing device determines, while the memory device is in the second state condition, an adjusted host rate, wherein the adjusted host rate is used to determine a credit consuming rate for a host operation.

First claim

What is claimed is:

1. A system comprising:
a memory device; and
a processing device, operatively coupled with the memory device, to perform operations comprising:
identifying a workload condition associated with the memory device;
determining a host rate associated with the memory device based on the workload condition;
detecting a change in a condition of the memory device from a first state condition to a second state condition; and
determining, while the memory device is in the second state condition, an adjusted host rate, wherein the adjusted host rate is used to determine a credit consuming rate for a host operation.

2. The system of claim 1 , wherein determining the host rate associated with the memory device based on the workload condition comprises:
determining a garbage collection rate for the memory device;
determining a current victim rate corresponding to a set of valid data on a block stripe of the memory device, wherein a garbage collection process is being performed on the block stripe;
determining a target free space for the memory device;
determining a current free space for the memory device; and
determining the host rate associated with the memory device based at least on the garbage collection rate, the current victim rate, the target free space, and the current free space.

3. The system of claim 1 , further comprising:
determining that the workload condition satisfies a first threshold criterion, wherein determining that the workload condition satisfies the first threshold criterion comprises:
determining a first ratio between an expected garbage collection write count for the memory device and an expected host write count for the memory device;
determining a second ratio between an actual garbage collection write count for the memory device and an actual host write count for the memory device; and
identifying a match between the first ratio and the second ratio.

4. The system of claim 3 , wherein determining that the workload condition satisfies the first threshold criterion further comprises:
determining a target free space for the memory device;
determining a current free space for the memory device; and
determining that the current free space of the memory device is within a threshold amount of the target free space for the memory device.

5. The system of claim 1 , wherein the processing device is configured to perform operations further comprising:
detecting a change in the condition of the memory device from the second state condition to the first state condition, wherein detecting the change in the condition of the memory device from the second state condition to the first state condition comprises determining that a current victim rate satisfies a second threshold criterion, wherein the current victim rate corresponds to a set of valid data on a block stripe of the memory device, wherein a garbage collection process is being performed on the block stripe.

6. The system of claim 1 , wherein the processing device is configured to perform operations further comprising:
detecting a change in the condition of the memory device from the second state condition to the first state condition, wherein detecting the change in the condition of the memory device from the second state condition to the first state condition comprises determining that a current free space for the memory device and a target free space for the memory device do not satisfy a threshold range criterion.

7. The system of claim 1 , wherein the processing device is configured to perform operations further comprising:
determining that the workload condition satisfies a first threshold criterion;
responsive to determining that the workload condition satisfies the first threshold criterion, determining, while the memory device is in the first state condition, a reference free space for the memory device, wherein the reference free space reflects one or more free pages of the memory device during the change in the condition of the memory device from the first state condition to the second state condition;
responsive to detecting the change in the condition of the memory device from the first state condition to the second state condition, determining, while the memory device is in the second state condition, a current free space for the memory device, wherein the current free space reflects one or more free pages of the memory device; and
determining, while the memory device is in the second state condition, a calculated adjustment value based at least on the reference free space and the current free space.

8. The system of claim 1 , wherein the first state condition comprises a memory condition wherein the performance condition of the memory device is unstable, and wherein the second state condition comprises a memory condition wherein the performance condition of the memory device is stable.

9. A method comprising:
identifying a workload condition associated with a memory device;
determining a host rate associated with the memory device based on the workload condition;
detecting a change in a condition of the memory device from a first state condition to a second state condition; and
determining, while the memory device is in the second state condition, an adjusted host rate, wherein the adjusted host rate is used to determine a credit consuming rate for a host operation.

10. The method of claim 9 , wherein determining the host rate associated with the memory device based on the workload condition comprises:
determining a garbage collection rate for the memory device;
determining a current victim rate corresponding to a set of valid data on a block stripe of the memory device, wherein a garbage collection process is being performed on the block stripe;
determining a target free space for the memory device;
determining a current free space for the memory device; and
determining the host rate associated with the memory device based at least on the garbage collection rate, the current victim rate, the target free space, and the current free space.

11. The method of claim 9 , further comprising:
determining that the workload condition satisfies a first threshold criterion, wherein determining that the workload condition satisfies the first threshold criterion comprises:
determining a first ratio between an expected garbage collection write count for the memory device and an expected host write count for the memory device;
determining a second ratio between an actual garbage collection write count for the memory device and an actual host write count for the memory device; and
identifying a match between the first ratio and the second ratio.

12. The method of claim 11 , wherein determining that the workload condition
satisfies the first threshold criterion further comprises:
determining a target free space for the memory device;
determining a current free space for the memory device; and
determining that the current free space of a plurality of block stripes is within a threshold amount of the target free space for the memory device.

13. The method of claim 9 , further comprising:
detecting a change in the condition of the memory device from the second state condition to the first state condition, wherein detecting the change in the condition of the memory device from the second state condition to the first state condition comprises determining that a current victim rate satisfies a second threshold criterion, wherein the current victim rate corresponds to a set of valid data on a block stripe of the memory device, wherein a garbage collection process is being performed on the block stripe.

Assignees

• Micron Technology Inc

Inventors

• Huang Ying
• Ish Mark

Classifications

• G06F3/0634 Primary

  by changing the state or mode of one or more devices · CPC title

• G06F3/0617

  in relation to availability · CPC title

• G06F3/0635

  by changing the path, e.g. traffic rerouting, path reconfiguration · CPC title

• G06F3/0659

  Command handling arrangements, e.g. command buffers, queues, command scheduling · CPC title

• G06F3/0679 Primary

  Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP] · CPC title