Zone-append command scheduling based on zone state
The present disclosure generally relates to scheduling zone-append commands for a zoned namespace (ZNS). Rather than taking zone-append commands in order or randomly, the zone-append commands can be scheduled in the most efficient manner consistent with the open zones of the ZNS. A zone priority is determined based upon the length of time that a zone has been open together with the zone status. Generally, the older the zone and/or the more full that a zone is increases the priority. Once the zone priority is established, the zone-append commands are scheduled to ensure the zone-append commands for the high priority zones are processed first so that the open zone can be filled prior to closing.
1. A data storage device, comprising:
a memory device;
a controller coupled to the memory device; and
means to schedule zone-append commands based upon an age of at least one open zone and a fullness of the at least one open zone in a zone namespace (ZNS) environment, wherein the fullness is less than a total capacity of the at least one open zone, wherein the zone-append commands contain a same address as the at least one open zone in the ZNS environment, wherein a priority is calculated based upon the age of the at least one open zone and the fullness of the at least one open zone, and wherein the calculated priority of the at least one open zone is higher than a calculated priority of another open zone in the ZNS environment, the zone-append commands of the at least one open zone are scheduled before other zone-append commands of the another open zone, the at least one open zone is filled prior to the at least one open zone being closed, and the calculated priority increases when the age increases or the fullness increases.
2. The data storage device of claim 1 , further comprising means to determine an age of all open zones.
3. The data storage device of claim 1 , further comprising means to instruct a command fetcher to fetch commands in accordance with instructions from the means to schedule.
4. The data storage device of claim 1 , further comprising means to monitor zone states of all open zones.
5. A data storage device, comprising:
a memory device; and
a controller coupled to the memory device, wherein the controller is configured to:
determine a fullness of at least one open zone in a zone namespace (ZNS) environment, wherein the fullness is less than a total capacity of the at least one open zone;
determine an age of the at least one open zone in the ZNS environment;
calculate a priority for the at least one open zone based upon the determined fullness and the determined age; and
process zone-append commands for the at least one open zone based upon the calculated priority, wherein the zone-append commands contain a same address as an open zone of the at least one open zone in the ZNS environment, wherein the calculated priority of the at least one open zone is higher than a calculated priority of another open zone in the ZNS environment, the zone-append commands of the at least one open zone are scheduled before other zone-append commands of the another open zone, the at least one open zone is filled prior to the at least one open zone being closed, and the calculated priority increases when the determined age increases or the determined fullness increases.
6. The data storage device of claim 5 , wherein the controller is configured to determine the fullness, determine the age, and calculate the priority for all open zones of the ZNS environment.
7. The data storage device of claim 6 , wherein the controller is configured to process the zone-append commands in order of priority from a high priority to a low priority.
8. The data storage device of claim 5 , wherein the controller comprises a zone-append command scheduler.
9. The data storage device of claim 8 , wherein the controller is further configured to send the calculated priority to the zone-append command scheduler.
10. The data storage device of claim 5 , wherein calculating the priority comprises adding together the determined fullness and the determined age.
11. The data storage device of claim 5 , wherein the controller is configured to determine the fullness, determine the age, and calculate the priority prior to fetching data from a host device.
12. A data storage device, comprising:
a memory device; and
a controller coupled to the memory device, wherein the controller comprises:
a command fetcher;
a command executor;
a flash interface module coupled to the memory device; and
a zone-append command scheduler coupled to the command fetcher, the command executor, and the flash interface module, wherein the zone-append command scheduler is configured to:
receive a zone-append command, wherein:
the zone-append command is based on a calculated priority;
the calculated priority is based on a fullness of at least one open zone and an age of the at least one open zone;
the fullness is less than a total capacity of the at least one open zone; and
the zone-append command contains a same address as the at least one open zone in a zone namespace (ZNS) environment; and
process the zone-append command for the at least one open zone based upon the calculated priority, wherein the calculated priority of the at least one open zone is higher than a calculated priority of another open zone in the ZNS environment, the zone-append command of the at least one open zone is scheduled before other zone-append commands of the another open zone, the at least one open zone is filled prior to the at least one open zone being closed, and the calculated priority increases when the age increases or the fullness increases.
13. The data storage device of claim 12 , wherein the zone-append command scheduler monitors an age of each zone in a zone namespace (ZNS) environment.
14. The data storage device of claim 13 , wherein the zone-append command scheduler monitors a fullness of each zone in the ZNS environment.
15. The data storage device of claim 12 , wherein the zone-append command scheduler is configured to instruct the command fetcher to fetch commands for each of zones based upon a calculated priority for each of the zones.
16. The data storage device of claim 15 , wherein the calculated priority for each of the zones is based upon an age of each of the zones and a fullness of each of the zones.
17. The data storage device of claim 12 , wherein the zone-append command scheduler is configured to provide a higher priority to zone-append commands to be written to a zone that has a longer period of time open compared to another zone.
18. The data storage device of claim 12 , wherein the zone-append command scheduler is configured to provide a higher priority to zone-append commands to be written to a zone that is closer to being full as compared to another zone.