Storage module and method for identifying hot and cold data

Patent metadata

Field	Value
Publication number	US-9747202-B1
Application number	US-201313829235-A
Country	US
Kind code	B1
Filing date	Mar 14, 2013
Priority date	Mar 14, 2013
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

A storage module and method for identifying hot and cold data are provided. The storage module can be removable from a host or can be embedded in a host. In one embodiment, a request to store data in a logical block address (LBA) of a memory of the storage module is received. A physical block associated with the LBA is determined, and it is also determined whether the physical block stores hot or cold data. A last-known open block is then selected, wherein the last-known open block is either hot or cold depending on whether the physical block stores hot or cold data. If space is available in the last-known open block, the data is written to the last-known open block.

First claim

What is claimed is:

1. A method for identifying hot and cold data, the method comprising:
performing the following in a storage module which is operatively in communication with a host:
receiving a request from the host to store data in a logical block address (LBA) of a memory of the storage module;
determining a first physical block associated with the LBA based on a logical-to-physical address map;
determining how recently the first physical block was last written to;
determining whether the LBA is hot or cold based on how recently the first physical block was last written to, wherein a size of the first physical block is larger than a size of the LBA;
in response to determining that the LBA is hot, storing the data in a second physical block, wherein the second physical block is designated for hot data; and
in response to determining that the LBA is cold, storing the data in a third physical block, wherein the third physical block is designated for cold data;
wherein, irrespective of whether the LBA is determined to be hot or cold, the data is stored in a different physical block than the one determined using the logical-to-physical address map.

2. The method of claim 1 further comprising:
selecting a last-known open block, wherein the last-known open block is either hot or cold depending on whether the first physical block stores hot or cold data;
if space is available in the last-known open block, writing the data from the host to the last-known open block; and
if space is not available in the last-known open block, writing the data from the host to a newly-allocated block.

3. The method of claim 1 , wherein the memory module determines how recently the first physical block was last written to by analyzing a list of most-recently open blocks.

4. The method of claim 3 , wherein a threshold for determining which blocks on the list are hot or cold is static.

5. The method of claim 3 , wherein a threshold for determining which blocks on the list are hot or cold is dynamic.

6. The method of claim 1 further comprising updating the logical-to-physical address map to associate the LBA with the second or third physical block, as appropriate.

7. The method of claim 1 further comprising performing garbage collection on the blocks in the memory while maintain a temperature of data being compacted.

8. The method of claim 7 further comprising, during garbage collection, placing a block with available pages at a beginning of a list.

9. A storage module comprising:
a memory; and
a processor in communication with the memory, wherein the processor is configured to:
receive a request from the host to store data in a logical block address (LBA) of the memory;
determine a first physical block associated with the LBA based on a logical-to-physical address map;
determine how recently the first physical block was last written to;
determine whether the LBA is hot or cold based on how recently the first physical block was last written to, wherein a size of the first physical block is larger than a size of the LBA;
in response to determining that the LBA is hot, store the data in a second physical block, wherein the second physical block is designated for hot data; and
in response to determining that the LBA is cold, store the data in a third physical block, wherein the third physical block is designated for cold data;
wherein, irrespective of whether the LBA is determined to be hot or cold, the data is stored in a different physical block than the one determined using the logical-to-physical address map.

10. The storage module of claim 9 , wherein the processor is further configured to:
select a last-known open block, wherein the last-known open block is either hot or cold depending on whether the first physical block stores hot or cold data;
if space is available in the last-known open block, write the data from the host to the last-known open block; and
if space is not available in the last-known open block, write the data from the host to a newly-allocated block.

11. The storage module of claim 9 , wherein the memory module determines how recently the first physical block was last written to by analyzing a list of most-recently open blocks.

12. The storage module of claim 11 , wherein a threshold for determining which blocks on the list are hot or cold is static.

13. The storage module of claim 11 , wherein a threshold for determining which blocks on the list are hot or cold is dynamic.

14. The storage module of claim 9 , wherein the processor is further configured to update the logical-to-physical address map to associate the LBA with the second or third physical block, as appropriate.

15. The storage module of claim 9 , wherein the processor is further configured to perform garbage collection on the blocks in the memory while maintain a temperature of data being compacted.

16. The storage module of claim 15 , wherein the processor is further configured to, during garbage collection, place a block with available pages at a beginning of a list.

17. A method for identifying hot and cold data, the method comprising:
performing the following in a host having embedded therein a host controller and a storage module:
receiving a request to store data in a logical block address (LBA) of a memory of the storage module;
determining a first physical block associated with the LBA based on a logical-to-physical address map;
determining how recently the first physical block was last written to;
determining whether the LBA is hot or cold based on how recently the first physical block was last written to, wherein a size of the first physical block is larger than a size of the LBA;
in response to determining that the LBA is hot, storing the data in a second physical block, wherein the second physical block is designated for hot data; and
in response to determining that the LBA is cold, storing the data in a third physical block, wherein the third physical block is designated for cold data;
wherein, irrespective of whether the LBA is determined to be hot or cold, the data is stored in a different physical block than the one determined using the logical-to-physical address map.

18. The method of claim 17 further comprising:
selecting a last-known open block, wherein the last-known open block is either hot or cold depending on whether the first physical block stores hot or cold data;
if space is available in the last-known open block, writing the data from the host to the last-known open block; and
if space is not available in the last-known open block, writing the data to a newly-allocated block.

19. The method of claim 17 , wherein determining how recently the first physical block was last written to is performed by analyzing a list of most-recently open blocks.

20. The method of claim 19 , wherein a threshold for determining which blocks on the list are hot or cold is static.

21. The method of claim 19 , wherein a threshold for determining which blocks on the list are hot or cold is dynamic.

22. The method of claim 17 further comprising updating the logical-to-physical address map to associate the last-known open block with the LBA.

23. The method of claim 17 further comprising performing garbage collection on the blocks in the memory while maintain a temperature of data being compacted.

24. The method of claim 23 further comprising, during garbage collection, placing a block with available pages at a beginning

Assignees

• Shaharabany Amir
• Marcu Alon
• Oshinsky Hadas
• Hacohen Adir Moshe
• Sandisk Technologies Llc

Inventors

• Shaharabany Amir
• Marcu Alon
• Oshinsky Hadas
• Hacohen Adir Moshe

Classifications

• G06F2212/7205

  Cleaning, compaction, garbage collection, erase control · CPC title

• G06F12/0253 Primary

  Garbage collection, i.e. reclamation of unreferenced memory · CPC title

• G06F2212/1024

  Latency reduction · CPC title

• G06F12/123

  with age lists, e.g. queue, most recently used [MRU] list or least recently used [LRU] list · CPC title

• G06F2212/7201

  Logical to physical mapping or translation of blocks or pages · CPC title