Thin provisioning L2P resource sharing
Logical to physical (L2P) tables are implemented in solid state drives (SSDs) to hold L2P address translations. In a thin provisioning or thin storage system, the L2P table is sized to support the total amount of memory that is available to be allocated on a per client or per host basis. During thin provisioning, the total amount of memory is not typically utilized. As such, the L2P table, which is sized to accommodate full usage of the memory allocated, is not fully utilized resulting in unused portions of the L2P table. The unused portions of the L2P table can be reallocated to use as temporal buffers until needed for write commands. Due to the reallocation, less buffers are needed.
1 . A data storage device, comprising:
a memory device; and
a controller coupled to the memory device, wherein the controller is configured to:
receive a write command;
determine that a relevant logical to physical (L2P) entry was allocated to other usage, wherein the other usage is selected from the group consisting of: part of a data path, a read look ahead (RLA) buffer, an exclusive or (XOR) buffer, and combinations thereof;
delay execution of the write command;
determine that the relevant L2P entry has been released; and
execute the write command.
2 . The data storage device of claim 1 , wherein the controller comprises a L2P table management module.
3 . The data storage device of claim 2 , wherein the L2P table management module includes a temporal buffer allocation unit and a reserved area management unit.
4 . The data storage device of claim 3 , wherein the temporal buffer allocation unit is configured to allocate the relevant L2P entry.
5 . The data storage device of claim 4 , wherein the reserved area management unit is configured to perform:
the determining that the relevant L2P entry was allocated to other usage; and
the determining that the relevant L2P entry has been released.
6 . The data storage device of claim 1 , wherein after the delaying and before the executing, the controller is configured to transfer data associated with the write command to intermediate buffers of the data storage device.
7 . The data storage device of claim 6 , wherein after the delaying and transferring, and before the executing, the controller is configured to post a write command completion notification for the write command to a host device.
8 . The data storage device of claim 1 , wherein the controller is configured to execute a thin provisioning method to allocate data storage.
9 . The data storage device of claim 1 , wherein the L2P entry is disposed in dynamic random access memory (DRAM).
10 . A data storage device, comprising:
a memory device; and
a controller coupled to the memory device, wherein the controller is configured to:
detect unused space within a logical to physical (L2P) table;
allocate the unused space as temporal buffers;
manage the unused space; and
detect collisions in the unused space, wherein the controller comprises a L2P table management module, and wherein the L2P table management module includes a temporal buffer allocation unit and a reserved area management unit.
11 . The data storage device of claim 10 , wherein the controller is configured to allocate data storage to a plurality of host devices.
12 . The data storage device of claim 11 , wherein the L2P table is sized to accommodate a number logical addresses greater than a total amount of available memory.
13 . The data storage device of claim 12 , wherein the L2P table is sized to accommodate thin provisioning.
14 . The data storage device of claim 10 , wherein the controller is configured to stop the allocating in response to the detecting collisions.
15 . The data storage device of claim 10 , wherein the controller is configured to delay execution of a write command associated with a collision.
16 . The data storage device of claim 10 , wherein managing the unused space comprises releasing the unused space from use as a temporal buffer.
17 . A data storage device, comprising:
means to store data; and
a controller coupled to the means to store data, wherein the controller is configured to:
execute a thin provisioning method to allocate data storage within the means to store data, wherein the thin provisioning method comprises utilizing a logical to physical (L2P) table;
detect that the L2P table has unused space;
allocate the unused space as temporal buffers;
delay execution of write commands associated with the unused space; and
execute write commands associated with the unused space upon release of the unused space from use as a temporal buffer, wherein after the delaying and before the executing, the controller is configured to transfer data associated with write commands to intermediate buffers of the data storage device.
18 . The data storage device of claim 17 , wherein a number of rows of the L2P table is equal to a maximum capacity of the means to store data.
19 . The data storage device of claim 17 , wherein the controller is configured to stop allocating the unused space associated with the write commands.