Dynamic and adaptive data read request scheduling
The present disclosure generally relates to a method and device for improving data read request scheduling in storage devices. When a connection between a host computer and a storage device is established, a controller of the storage device sets a maximum outstanding read requests threshold for the storage device, based on the host-device connection protocol. The maximum outstanding read requests threshold can be dynamically adjusted in response to changes in the host-device connection protocol. Further, a latency tracker of the controller may be used to measure latency between the host computer and the storage device and adjust the maximum outstanding read requests threshold accordingly.
1. A storage device comprising:
a non-volatile memory; and
a controller coupled to the non-volatile memory, wherein the controller is configured to:
establish a dynamic read request threshold for data read requests from the storage device to a host computer upon connection of the storage device to the host computer, wherein the dynamic read request threshold is a number of read requests, wherein the dynamic read request threshold is adjusted based on a change in a host-device protocol parameter, and wherein the host-device protocol parameter comprises a number of lanes; and
adjust, based on the dynamic read request threshold, a size of a reserved space of a read memory for data to be transferred to in response to the number of read requests, wherein the size of the reserved space is substantially equal to the dynamic read request threshold.
2. The storage device of claim 1 , further comprising a latency tracker configured to measure a read latency between the storage device and the host computer.
3. The storage device of claim 2 , the controller being further configured to adjust the dynamic read request threshold based on the read latency between the storage device and the host computer.
4. The storage device of claim 1 , wherein the controller is configured to establish the dynamic read request threshold based on the host-device protocol between the storage device and the host computer.
5. The storage device of claim 4 , the controller being further configured to:
detect a change in the host-device protocol; and
adjust the dynamic read request threshold based on the change in the host-device protocol.
6. The storage device of claim 1 , further comprising a latency tracker configured to measure a read latency between the storage device and the host computer, wherein the controller is further configured to:
establish the dynamic read request threshold based on a host-device protocol between the storage device and the host computer; and
adjust the dynamic read request threshold based on the read latency between the storage device and the host computer.
7. The storage device of claim 1 , wherein the controller further comprises a latency tracker coupled to a dynamic threshold controller.
8. The storage device of claim 7 , wherein the controller further comprises a read request buffer coupled to the dynamic threshold controller.
9. The storage device of claim 8 , wherein the controller further comprises a direct memory access (DMA) coupled to the read request buffer.
10. A storage device, comprising:
a non-volatile memory; and
a controller coupled to the non-volatile memory, the controller is configured to:
determine a connection has been established between a storage device and a host computer;
determine an initial value for a dynamic read request threshold for the storage device, wherein the dynamic read request threshold is a number of read requests;
transmit at least one data read request from the storage device to the host computer;
adjust the initial value for the dynamic read request threshold based on transmitting the at least one data read request, wherein the dynamic read request threshold is adjusted based on a host-device protocol parameter, and wherein the host-device protocol parameter comprises a number of lanes; and
adjust, based on the dynamic read request threshold, a size of a reserved space of a read memory for data to be transferred to in response to the number of read requests, wherein the size of the reserved space is substantially equal to the dynamic read request threshold.
11. The storage device of claim 10 , wherein determining the initial value for the dynamic read request threshold comprises:
determining a host-device protocol of the connection; and
establishing the initial value based on the host-device protocol.
12. The storage device of claim 11 , wherein the controller is further configured to detect a change in the host-device protocol, wherein the initial value for the dynamic read request is adjusted based on the change in the host-device protocol.
13. The storage device of claim 11 , wherein adjusting the initial value for the dynamic read request threshold based on transmitting the at least one data read request comprises:
receiving a read latency measurement from a latency tracker; and
adjusting the initial value based on the read latency measurement.
14. The storage device of claim 10 , wherein the controller further comprises a read request buffer.
15. The storage device of claim 10 , wherein the controller further comprises a latency tracker.
16. The storage device of claim 10 , wherein the controller further comprises a dynamic threshold controller.
17. A storage device, comprising:
a non-volatile memory;
means to dynamically adjust a read request threshold, wherein the read request threshold is a number of read requests, wherein the read request threshold is adjusted based on a host-device protocol parameter, and wherein the host-device protocol parameter comprises a number of lanes; and
means to dynamically adjust, based on the read request threshold, a size of a reserved space of a read memory for data to be transferred to in response to the number of read requests, wherein the size of the reserved space is substantially equal to the read request threshold.
18. The storage device of claim 17 , further comprising means to track latency.
19. The storage device of claim 17 , further comprises means to detect a change in host-device protocol.
20. The storage device of claim 17 , further comprising means to adjust an initial value for the read request threshold based on transmitting a data read request.