Managing redundancy contexts in storage devices using eviction and restoration
A controller selects a redundancy context for eviction in response to a request for a redundancy context. The redundancy context includes buffer data and an identifier. The redundancy context is evicted by instructing a redundancy component to send the buffer data and identifier to a memory component to store in a buffer as an evicted context. The controller instructs the memory component to provide the evicted context for storage in a controller buffer. A new redundancy context is allocated to the requester following the eviction.
1. A computer-implemented method comprising:
receiving a first request to allocate a portion of a first memory as a redundancy context, wherein the first memory includes a plurality of redundancy contexts temporarily storing data used to calculate redundancy values for the data;
selecting an idle redundancy context for eviction in response to the first request, wherein the idle redundancy context includes a first buffer of data and a context identifier;
evicting contents of the idle redundancy context by sending the first buffer of data and the context identifier to a memory component of a second memory;
retrieving the contents of the evicted context from the memory component of the second memory;
storing the retrieved contents of the evicted context in a second buffer; and
allocating the portion of the first memory as a new redundancy context in response to the first request and the eviction.
2. The method of claim 1 , further comprising:
receiving a second request, the second request directed to the contents of the evicted context;
restoring the contents of the evicted context stored in the third second buffer to an available redundancy context; and
providing the restored redundancy context in response to the second request.
3. The method of claim 2 , wherein the first request is from a first process writing data at a first rate and wherein the second request is from a second process writing data at a second rate and wherein the first rate is greater than the second rate.
4. The method of the claim 2 , wherein restoring the contents of the evicted context comprises:
clearing contents of a third buffer;
storing in the third buffer a result of performing a logical operation on the cleared contents of the third buffer and the data from the contents of the evicted context; and
storing the context identifier from the contents of the evicted context in the available redundancy context.
5. The method of claim 4 , wherein the logical operation is a bitwise exclusive-or (XOR) operation.
6. The method of claim 1 , wherein the plurality of redundancy contexts is stored in a circular list and wherein each redundancy context is accessed through a sliding window within the circular list.
7. The method of claim 6 , wherein selecting the idle redundancy context for eviction includes determining that the redundancy context is preventing the sliding window from advancing to a next available redundancy context.
8. A non-transitory computer-readable storage medium comprising instructions that, when executed by a processing device, cause the processing device to:
receive a first request to allocate a portion of a first memory as a redundancy context, wherein the first memory includes a plurality of redundancy contexts temporarily storing data used to calculate redundancy values for the data;
select an idle redundancy context for eviction in response to the first request, wherein the idle redundancy context includes a first buffer of data and a context identifier;
evict contents of the idle redundancy context by sending the first buffer of data and the context identifier to a memory component of a second memory;
retrieve the contents of the evicted context from the memory component of the second memory;
store the retrieved contents of the evicted context in a second buffer; and
allocate the portion of the first memory as a new redundancy context in response to the first request and the eviction.
9. The storage medium of claim 8 , the instructions further causing the processing device to:
receive a second request, the second request directed to the contents of the evicted context;
restore the contents of the evicted context stored in the second buffer to an available redundancy context; and
provide the restored redundancy context in response to the second request.
10. The storage medium of claim 9 , wherein the first request is from a first process writing data at a first rate and wherein the second request is from a second process writing data at a second rate and wherein the first rate is greater than the second rate.
11. The storage medium of the claim 9 , wherein instructions causing the processing device to restore the available redundancy context further includes instructions causing the processing device to:
clear contents of a third buffer;
store in the third buffer a result of performing a logical operation on the cleared contents of the third buffer and the data from the contents of the evicted context; and
store the context identifier from the contents of the evicted context in the available redundancy context.
12. The storage medium of claim 11 , wherein the logical operation is a bitwise exclusive-or (XOR) operation.
13. The storage medium of claim 12 , wherein the plurality of redundancy contexts is stored in a circular list and wherein each redundancy context is accessed through a sliding window within the circular list.
14. The storage medium of claim 13 , wherein selecting the redundancy context for eviction includes determining that the redundancy context is preventing the sliding window from advancing to a next available redundancy context.
15. A system comprising:
a memory component; and
a processing device, coupled to the memory component, configured to:
receive a first request to allocate a portion of a first memory as a redundancy context, wherein the first memory includes a plurality of redundancy contexts temporarily storing data used to calculate redundancy values for the data;
select an idle redundancy context for eviction in response to the first request, wherein the idle redundancy context includes a first buffer of data and a context identifier;
evict contents of the idle redundancy context by sending the first buffer of data and the context identifier to a memory component of a second memory;
retrieve the contents of the evicted context from the memory component of the second memory;
store the retrieved contents of the evicted context in a second buffer; and
allocate the portion of the first memory as a new redundancy context in response to the first request and the eviction,
receive a second request, the second request directed to the contents of the evicted context;
restore the contents of the evicted context stored in the third second buffer to an available redundancy context; and
provide the restored redundancy context in response to the second request.
16. The system of claim 15 , wherein the first request is from a first process writing data at a first rate and wherein the second request is from a second process writing data at a second rate and wherein the first rate is greater than the second rate.
17. The system of the claim 15 , wherein restoring the available redundancy context further configures the processing device to:
clear contents of a third buffer;
store in the third buffer a result of performing a logical operation on the cleared contents of the third buffer and the data from the contents of the evicted context; and
store the context identifier from the contents of the evicted context in the available redundancy context.
18. The system of claim 17 , wherein the logical operation is a bitwise exclusive-or (XOR) operation.
19. The system of claim 18 , wherein the plurality of redundancy contexts is stored in a circular list and wherein each redundancy context is accessed through a sliding window within the circular list.
20. The system of claim 19 , wherein selecting the redundancy context for eviction includes determining that the redundancy context is preventing the sliding window from advancing to a next available redundancy context.