Namespaces Allocation in Non-Volatile Memory Devices

• US 20190121547A1
• Filed: 10/23/2017
• Published: 04/25/2019
• Est. Priority Date: 10/23/2017
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Frolikov, Alex
• Granted Patent: US 10,437,476 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 13/4282 on a serial bus, e.g. I2C bus, SPI bus on daisy chain buses G06F13/4247
• CPC Class Codes: G06F 2212/1016 Performance improvement
• CPC Class Codes: G06F 2212/1056 Simplification
• CPC Class Codes: G06F 2212/7201 Logical to physical mapping or translation of blocks or pages
• CPC Class Codes: G06F 2212/7204 Capacity control, e.g. partitioning, end-of-life degradation
• CPC Class Codes: G06F 2213/0026 PCI express
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0652 Erasing, e.g. deleting, data cleaning, moving of data to a wastebasket
• CPC Class Codes: G06F 3/0673 Single storage device
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A computer storage device having a host interface, a controller, non-volatile storage media, and firmware. The firmware instructs the controller to: receive, via the host interface, a request from a host to allocate a namespace of a quantity of non-volatile memory; generate, in response to the request, a namespace map identifying a plurality of blocks of addresses having a same predetermined block size, and a partial block of addresses having a size smaller than the predetermined block size; and convert, using the namespace map, logical addresses in the namespace communicated from the host to physical addresses for the quantity of the non-volatile memory. For example, the request for allocating the namespace can be in accordance with an NVMe protocol.

Claims

1. A computer storage device, comprising:

a host interface;

a controller;

non-volatile storage media; and

firmware containing instructions which, when executed by the controller, instruct the controller to at least;

receive, via the host interface, a request from a host to allocate a namespace of a quantity of non-volatile memory;

generate, in response to the request, a namespace map identifying;

a plurality of blocks of addresses having a same predetermined block size; and

a partial block of addresses having a size smaller than the predetermined block size; and

convert, using the namespace map, logical addresses in the namespace communicated from the host to physical addresses for the quantity of the non-volatile memory.

2. The computer storage device of claim 1, wherein the request to allocate the namespace is in accordance with a Non-Volatile Memory Host Controller Interface Specification (NVMHCI).

3. The computer storage device of claim 1, wherein the computer storage device is a solid state drive.

4. A method implemented in a computer storage device, the method comprising:

receiving, in a controller coupled with a non-volatile memory, a request from a host to create or reserve a namespace of a quantity of non-volatile memory;

generating, by the controller in response to the request, a namespace map identifying;

a plurality of blocks of addresses having a same predetermined block size; and

a partial block of addresses having a size smaller than the predetermined block size; and

converting, by the controller using the namespace map, logical addresses in the namespace communicated from the host to physical addresses for the quantity of the non-volatile memory.

5. The method of claim 4, wherein the request is in accordance with a Non-Volatile Memory Host Controller Interface Specification (NVMHCI).

6. The method of claim 4, wherein each of the plurality of blocks is represented in the namespace map by an identification of a starting unit.

7. The method of claim 6, wherein the partial block is represented in the namespace map by an identification of a unit allocated for the namespace and a chunk size.

8. The method of claim 7, further comprising:

maintaining, in the computer storage device, a free block pool identifying at least one partial block of addresses.

9. The method of claim 8, wherein the generating of the namespace map comprises:

allocating the plurality of blocks for the namespace;

determining a difference between the quantity of non-volatile memory requested for the namespace and a total size of the plurality of blocks; and

searching in the free block pool for a partial block of addresses that is equal to or larger than the difference.

10. The method of claim 9, wherein the generating of the namespace map further comprises, in response to a determination that the free block pool has a first partial block of addresses having a size larger than the difference:

allocating a portion of the first partial block for the namespace; and

updating the first partial block in the free block pool to represent a remaining portion of first partial block that is not allocated for the namespace.

11. The method of claim 9, wherein the generating of the namespace map further comprises, in response to a determination that the free block pool has a first partial block of addresses having a size equal to the difference:

removing the first partial block from the free block pool; and

allocating the first partial block for the namespace.

12. The method of claim 9, wherein the generating of the namespace map further comprises, in response to a determination that the free block pool has no partial block of addresses having a size equal to or larger than the difference:

adding a first block of addresses having the same predetermined block size to the free block pool;

allocating a portion of the first block for the namespace; and

updating the first block in the free block pool to represent a remaining portion of the first block that is not allocated for the namespace.

13. The method of claim 8, further comprising:

receiving, in the controller, a request from the host to delete the namespace; and

adding, by the controller, the partial block identified in the namespace to the free block pool.

14. The method of claim 13, further comprising:

identifying, in the free block pool, contiguous free partial blocks; and

combining, in the free block pool, the contiguous free partial blocks into a single free partial block.

15. The method of claim 14, further comprising:

determining whether the single free partial block has the predetermined block size; and

in response to a determination that the single free partial block has the predetermined block size, removing the single free partial block from the free block pool.

16. The method of claim 15, wherein each block in the free block pool is represented by an identification of a starting unit and a chunk size.

17. A non-transitory computer storage medium storing instructions which, when executed by a controller of a computer storage device, cause the controller to perform a method, the method comprising:

receiving, in the controller coupled with a non-volatile memory, a request from a host to create or reserve a namespace of a quantity of non-volatile memory;

generating, by the controller in response to the request, a namespace map identifying;

a plurality of blocks of addresses having a same predetermined block size; and

a partial block of addresses having a size smaller than the predetermined block size; and

converting, by the controller using the namespace map, logical addresses in the namespace communicated from the host to physical addresses for the quantity of the non-volatile memory.

18. The non-transitory computer storage medium of claim 17, wherein each of the plurality of blocks are represented in the namespace map by an identification of a starting unit;

and the partial block is represented in the namespace map by an identification of a starting unit and a chunk size.

19. The non-transitory computer storage medium of claim 18, further comprising:

maintaining, in the computer storage device, a free block pool identifying at least one partial block of addresses, wherein the generating of the namespace map comprises;

allocating the plurality of blocks;

determining a difference between the quantity of non-volatile memory requested for the namespace and a total size of the plurality of blocks; and

searching in the free block pool for a partial block of addresses that is equal to or larger than the difference.

20. The non-transitory computer storage medium of claim 19, further comprising:

receiving, in the controller, a request from the host to delete the namespace;

adding, by the controller, the partial block identified in the namespace to the free block pool;

identifying, in the free block pool, contiguous free partial blocks; and

combining, in the free block pool, the contiguous free partial blocks into a single free partial block.