APPARATUS, SYSTEM, AND METHOD FOR AN ADDRESS TRANSLATION LAYER

• US 20130080732A1
• Filed: 09/27/2012
• Published: 03/28/2013
• Est. Priority Date: 09/27/2011
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Fusion-IO Incorporated (Western Digital Corporation)
• Inventors: Nellans, David, Piggin, Nick, Axboe, Jens
• Granted Patent: US 9,690,694 B2
• Time in Patent Office: Days
• US Class Current: 711/206
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/7201 Logical to physical mapping or translation of blocks or pages

Abstract

An apparatus, system, and method are disclosed for storage address translation. The method includes storing, in volatile memory, a plurality of logical-to-physical mapping entries for a non-volatile recording device. The method includes persisting a logical-to-physical mapping entry from the volatile memory to recording media of the non-volatile recording device. The logical-to-physical mapping entry may be selected for persisting based on a mapping policy indicated by a client. The method includes loading the logical-to-physical mapping entry from the recording media of the non-volatile recording device into the volatile memory in response to a storage request associated with the logical-to-physical mapping entry.

Claims

1. A method for storage address translation, the method comprising:

storing, in volatile memory, a plurality of logical-to-physical mapping entries for a non-volatile recording device;

persisting a logical-to-physical mapping entry from the volatile memory to recording media of the non-volatile recording device, the logical-to-physical mapping entry selected for persisting based on a mapping policy indicated by a client; and

loading the logical-to-physical mapping entry from the recording media of the non-volatile recording device into the volatile memory in response to a storage request associated with the logical-to-physical mapping entry.

2. The method of claim 1, further comprising receiving an advisement message from the client, the advisement message indicating the mapping policy for the logical-to-physical mapping entry.

3. The method of claim 2, wherein the advisement message comprises an access pattern indicator for a logical address associated with the logical-to-physical mapping entry, and the mapping policy is determined at least in part based on the access pattern indicator.

4. The method of claim 2, wherein the advisement message comprises a directive indicating that the logical-to-physical mapping entry is to be persisted.

5. The method of claim 1, further comprising determining the mapping policy based on a type of the client.

6. The method of claim 1, further comprising determining the mapping policy based on a set of configuration settings for the client.

7. The method of claim 1, further comprising selecting a subsequent logical-to-physical mapping entry to persist based on an access history of a logical address associated with the subsequent logical-to-physical mapping entry.

8. The method of claim 1, wherein a logical address space of the non-volatile recording device is divided into zones and the logical-to-physical mapping entry is selected for persisting based on the mapping policy of a zone associated with the logical-to-physical mapping entry.

9. The method of claim 8, further comprising providing a differentiated quality-of-service for the different zones of the logical address space based on the different mapping policies.

10. The method of claim 9, wherein the differentiated quality-of-service comprises different maximum latencies for each zone, the logical-to-physical mapping entry selected for persisting to provide a specified maximum latency for the zone associated with the logical-to-physical mapping entry.

11. The method of claim 1, wherein the recording media of the non-volatile recording device is fully associative with a logical address space of the non-volatile recording device.

12. The method of claim 1, wherein the plurality of logical-to-physical mapping entries in volatile memory comprise a sparsely populated logical-to-physical mapping structure with entries only for logical addresses for which the non-volatile recording devices stores data, the entries dynamically paged between the volatile memory and the recording media.

13. The method of claim 1, wherein the logical-to-physical mapping entry maps a logical address of a logical address space of the non-volatile recording device to a physical location where data of the logical address is stored within a sequential log-based writing structure of the non-volatile recording device.

14. The method of claim 1, wherein the logical-to-physical mapping entry is persisted to a reserved range of logical addresses, one or more logical-to-physical mapping entries for the reserved range of logical addresses pinned in the volatile memory.

15. The method of claim 14, further comprising masking the reserved range of logical addresses with an offset such that the reserved range of logical addresses is inaccessible to clients.

16. The method of claim 1, wherein the volatile memory comprises internal memory of the non-volatile recording device.

17. An apparatus for storage address translation, the apparatus comprising:

a mapping module configured to store, in volatile memory, logical-to-physical mapping entries mapping logical addresses to physical locations in a non-volatile memory device;

a persist module configured to dynamically flush logical-to-physical mapping entries from the volatile memory to non-volatile memory media of the non-volatile memory device based on a plurality of client selectable mapping policies for the logical-to-physical mapping entries; and

a load module configured to dynamically load one or more logical-to-physical mapping entries from the non-volatile memory media of the non-volatile memory device into the volatile memory to service storage requests without loading one or more additional logical-to-physical mapping entries from the non-volatile memory media.

18. The apparatus of claim 17, further comprising an advisement module configured to receive an advisement message from a client, the persist module configured to select a logical-to-physical mapping entry to flush based on a mapping policy indicated by the advisement message.

19. The apparatus of claim 17, further comprising an access history module configured to select a logical-to-physical mapping entry for the persist module to flush based on an access history of a logical address associated with the selected logical-to-physical mapping entry.

20. The apparatus of claim 17, further comprising a zone module configured to maintain a plurality of address ranges within a logical address space of the non-volatile memory device, each address range associated with a mapping policy, the persist module configured to select a logical-to-physical mapping entry to flush based on the mapping policy of an address range of a logical address associated with the selected logical-to-physical mapping entry.

21. A system for storage address translation, the system comprising:

a non-volatile storage device coupled to a host computing device, the non-volatile storage device comprising non-volatile storage media; and

a storage management layer for a non-volatile storage device, the storage management layer executing on the host computing device, the storage management layer comprising,

an advisement module configured to receive an advisement message from a client, the advisement message indicating a mapping policy for one or more logical-to-physical mapping entries for the non-volatile storage device;

a persist module configured to evict a logical-to-physical mapping entry from volatile memory of the host device to the non-volatile storage media of the non-volatile storage device based on the mapping policy, the eviction freeing capacity of the volatile memory; and

a load module configured to load a different logical-to-physical mapping entry from the non-volatile storage media into the freed capacity of the volatile memory.

22. The system of claim 21, further comprising the host computing device, the non-volatile storage device coupled to the host computing device over a communications bus, the persist module evicting the logical-to-physical mapping entry to the non-volatile storage media over the communications bus.

23. A computer program product comprising a computer readable storage medium storing computer usable program code executable to perform operations for storage address translation, the operations comprising:

selecting one or more logical-to-physical mapping entries of a non-volatile recording device to store in volatile memory based on a mapping policy for the one or more logical-to-physical mapping entries;

selecting one or more different logical-to-physical mapping entries of the non-volatile recording device to store in recording media of the non-volatile recording device based on a different mapping policy for the different logical-to-physical mapping entries; and

loading the one or more different logical-to-physical mapping entries from the recording media of the non-volatile recording device into the volatile memory to service a storage request.

24. The computer program product of claim 23, the operations further comprising servicing the storage request using the one or more different logical-to-physical mapping entries in the volatile memory.

25. An apparatus for storage address translation, the apparatus comprising:

means for receiving a storage request for a non-volatile memory device;

means for loading a logical-to-physical mapping entry from non-volatile memory media of the non-volatile memory device into volatile memory, the logical-to-physical mapping entry associated with the storage request; and

means for persisting a different logical-to-physical mapping entry from the volatile memory to the non-volatile memory media of the non-volatile memory device to satisfy a volatile memory allotment threshold for logical-to-physical mapping entries in the volatile memory.

26. The apparatus of claim 25, further comprising means for selecting the different logical-to-physical mapping entry to persist based on one or more client configurable mapping policies.