Memory sub-system for supporting deterministic and non-deterministic commands based on command expiration and the state of the intermediate command queue
View Patent ↗Commands in a command queue are received and scheduled. For each of the commands, scheduling includes determining an age of a command based on an entrance time of the command in the command queue. When the age of the command satisfies a first threshold, marking all other commands in the command queue as not issuable when the command is a deterministic command, and marking all other commands in the command queue as not issuable when the command is a non-deterministic command and the intermediate command queue is not empty. Scheduling the command further includes determining whether the command is a read command and marking the command as not issuable when the command is a non-deterministic read command and the intermediate command queue is empty.
1. A system comprising:
a plurality of memory components; and
a processing device operatively coupled with the plurality of memory components, the processing device configured to perform operations comprising:
receiving a plurality of commands in a command queue, wherein the plurality of commands are directed to the plurality of memory components; and
scheduling the plurality of commands in the command queue, wherein scheduling the commands comprises, for each of the plurality of commands:
determining an age of a command based on an entrance time of the command in the command queue,
when the age of the command satisfies a first threshold,
marking other commands in the command queue as not issuable when the command is a deterministic command, and
marking other commands in the command queue as not issuable when the command is a non-deterministic command and an intermediate command queue is not empty,
determining whether the command is a read command, and
marking the command as not issuable when the command is a non-deterministic read command and the intermediate command queue is empty.
2. The system of claim 1 , wherein the memory components comprising a volatile memory component receiving deterministic commands and a non-volatile memory component receiving non-deterministic commands.
3. The system of claim 2 , wherein the plurality of commands received in the command queue comprise non-deterministic commands and deterministic commands.
4. The system of claim 3 , wherein the volatile memory component is a Dynamic Random-Access Memory (DRAM) and the non-volatile memory component is a Non-Volatile Dual In-Line Memory Module (NVDIMM), wherein the non-deterministic commands are NVDIMM-P commands, and deterministic commands are DRAM commands.
5. The system of claim 4 , wherein the intermediate command queue receives an intermediate command indicating that data associated with the non-deterministic read command is ready for transmission, wherein the non-deterministic read command is an XREAD command.
6. The system of claim 1 , wherein the processing device is configured to perform operations further comprising:
performing order buffer arbitration comprising:
receiving the non-deterministic command at a first port of an order buffer arbiter; and
adapting a maximum number of order buffer entries associated with the first port based on whether there is the deterministic command at a second port of the order buffer arbiter.
7. The system of claim 6 , wherein the maximum number of order buffer entries associated with the first port is decreased to a predetermined contention limit associated with the first port when there is the deterministic command at the second port.
8. The system of claim 7 , wherein deterministic commands are received at the second port of the order buffer arbiter.
9. The system of claim 8 , wherein the maximum number of order buffer entries associated with the first port is set to a predetermined maximum limit associated with the first port when there is not the deterministic command at the second port.
10. The system of claim 9 , the processing device configured to perform operations further comprising:
pre-decoding the deterministic commands and the non-deterministic commands from the order buffer arbiter, wherein the plurality of commands received in the command queue comprise the pre-decoded commands.
11. A method comprising:
receiving a plurality of commands in a command queue, wherein the plurality of commands are directed to a plurality of memory components; and
scheduling the plurality of commands in the command queue, wherein scheduling the commands comprises, for each of the plurality of commands:
determining an age of a command based on an entrance time of the command in the command queue,
when the age of the command satisfies a first threshold,
marking other commands in the command queue as not issuable when the command is a deterministic command, and
marking other commands in the command queue as not issuable when the command is a non-deterministic command and an intermediate command queue is not empty,
determining whether the command is a read command, and
marking the command as not issuable when the command is a non-deterministic read command and the intermediate command queue is empty.
12. The method of claim 11 , wherein the plurality of commands received in the command queue comprise non-deterministic commands and deterministic commands, wherein the deterministic commands are commands to volatile memory components and the non-deterministic commands are commands to non-volatile memory components.
13. The method of claim 12 , wherein the volatile memory component is a Dynamic Random-Access Memory (DRAM) and the non-volatile memory component is a Non-Volatile Dual In-Line Memory Module (NVDIMM), wherein the non-deterministic commands are NVDIMM-P commands, and deterministic commands are DRAM commands.
14. The method of claim 13 , wherein the intermediate command queue receives an intermediate command indicating that data associated with the non-deterministic read command is ready for transmission, wherein the non-deterministic read command is an XREAD command.
15. The method of claim 11 , further comprising:
performing order buffer arbitration comprising:
receiving the non-deterministic command at a first port of an order buffer arbiter, and
adapting a maximum number of order buffer entries associated with the first port based on whether there is the deterministic command at a second port of the order buffer arbiter.
16. The method of claim 15 , the maximum number of order buffer entries associated with the first port is decreased to a predetermined contention limit associated with the first port when there is the deterministic command at the second port.
17. The method of claim 16 , wherein deterministic commands are received at the second port of the order buffer arbiter.
18. The method of claim 17 , wherein the maximum number of order buffer entries associated with the first port is set to a predetermined maximum limit associated with the first port when there is not the deterministic command at the second port.
19. The method of claim 18 , further comprising:
pre-decoding the deterministic commands and the non-deterministic commands from the order buffer arbiter, wherein the plurality of commands received in the command queue comprise the pre-decoded commands.
20. At least one non-transitory machine-readable storage medium comprising instructions that, when executed by a processing device, cause the processing device to perform operations comprising:
receiving a plurality of commands in a command queue, wherein the plurality of commands are directed to a plurality of memory components;
scheduling the plurality of commands in the command queue, wherein scheduling the commands comprises, for each of the plurality of commands:
determining an age of a command based on an entrance time of the command in the command queue,
when the age of the command satisfies a first threshold,
marking other commands in the command queue as not issuable when the command is a deterministic command, and
marking other commands in the command queue as not issuable when the command is a non-deterministic command and an intermediate command queue is not empty,
determining whether the command is a read command, and
marking the command as not issuable when the command is non-deterministic read command and the intermediate command queue is empty.