According to one embodiment, a memory system includes a first compression unit, a second compression unit, a non-volatile memory, a first decoding unit, a conversion unit and an output unit. The first compression unit is configured to output second data obtained by compressing first data. The second compression unit is configured to output third data obtained by compressing the second data. Fourth data based on the third data is written to the non-volatile memory. The first decoding unit is configured to decode the third data based on the fourth data to the second data. The conversion unit is configured to acquire fifth data by converting a format of the second data. The output unit is configured to output the fifth data to a host.

According to one embodiment, a memory system includes a first compression unit, a second compression unit, a non-volatile memory, a first decoding unit, a conversion unit and an output unit. The first compression unit is configured to output second data obtained by compressing first data. The second compression unit is configured to output third data obtained by compressing the second data. Fourth data based on the third data is written to the non-volatile memory. The first decoding unit is configured to decode the third data based on the fourth data to the second data. The conversion unit is configured to acquire fifth data by converting a format of the second data. The output unit is configured to output the fifth data to a host.

Systems and methods are disclosed to implement an endpoint command invocation system (“ECIS”). In some embodiments, ECIS can quickly dispatch a command to a large number of endpoint components, where the endpoint components are online. ECIS can receive an invocation of a command, which can include the command recipients. In some embodiments, ECIS determines that some of the command recipients are online, while some of the command recipients are offline. ECIS determines connections to the online command recipients based on a connection map, which is updated whenever an endpoint component opens a connection to ask for a command. ECIS can deliver the command to the online command recipients using the connections. ECIS can also deliver the command to dispatch queues corresponding to the offline command recipients, where the dispatch queues store the command as a pending command that can be delivered to their respective command recipients whenever they come online.

Systems and methods are disclosed to implement an endpoint command invocation system (“ECIS”). In some embodiments, ECIS can quickly dispatch a command to a large number of endpoint components, where the endpoint components are online. ECIS can receive an invocation of a command, which can include the command recipients. In some embodiments, ECIS determines that some of the command recipients are online, while some of the command recipients are offline. ECIS determines connections to the online command recipients based on a connection map, which is updated whenever an endpoint component opens a connection to ask for a command. ECIS can deliver the command to the online command recipients using the connections. ECIS can also deliver the command to dispatch queues corresponding to the offline command recipients, where the dispatch queues store the command as a pending command that can be delivered to their respective command recipients whenever they come online.

Examples described herein relate to prioritizing read input/output (IO) queues in non-volatile memory express (NVME) storage devices. An NVME controller includes a host port, which may be associated with a host and communicate with NVME storage devices. A utilization time of the host port is determined. In response to determining that the utilization time of the host port is below a host port utilization threshold, the NVME controller may create a candidate list of NVME storage devices based on utilizations, throughputs, busy time periods, and IO request completions of the NVME storage devices. For each NVME storage device included in the candidate list, a number of read requests in a read IO queue at the NVME storage device may be determined. A priority rank may be assigned to the read IO queue at each NVME storage device based on the number of read requests in that read IO queue.

A host controller interface configured to provide interfacing between a host device and a storage device includes processing circuitry; a doorbell register configured to store a head pointer and a tail pointer of one or more first queues; and an entry buffer configured to store a first command from one of the one or more first queues in the entry buffer, wherein the processing circuitry is configured to, determine an order in which the commands of the one or more first queues are to be processed, route the first command to be stored in the entry buffer according to the determined order, and route a first response to be stored in one of one or more second queues.

A host controller interface configured to provide interfacing between a host device and a storage device includes processing circuitry; a doorbell register configured to store a head pointer and a tail pointer of one or more first queues; and an entry buffer configured to store a first command from one of the one or more first queues in the entry buffer, wherein the processing circuitry is configured to, determine an order in which the commands of the one or more first queues are to be processed, route the first command to be stored in the entry buffer according to the determined order, and route a first response to be stored in one of one or more second queues.

A queuing requester for access to a memory system is provided. Transaction requests are received from two or more requestors for access to the memory system. Each transaction request includes an associated priority value. A request queue of the received transaction requests is formed in the queuing requester. Each transaction request includes an associated priority value. A highest priority value of all pending transaction requests within the request queue is determined. An elevated priority value is selected when the highest priority value is higher than the priority value of an oldest transaction request in the request queue; otherwise the priority value of the oldest transaction request is selected. The oldest transaction request in the request queue with the selected priority value is then provided to the memory system. An arbitration contest with other requesters for access to the memory system is performed using the selected priority value.

A queuing requester for access to a memory system is provided. Transaction requests are received from two or more requestors for access to the memory system. Each transaction request includes an associated priority value. A request queue of the received transaction requests is formed in the queuing requester. Each transaction request includes an associated priority value. A highest priority value of all pending transaction requests within the request queue is determined. An elevated priority value is selected when the highest priority value is higher than the priority value of an oldest transaction request in the request queue; otherwise the priority value of the oldest transaction request is selected. The oldest transaction request in the request queue with the selected priority value is then provided to the memory system. An arbitration contest with other requesters for access to the memory system is performed using the selected priority value.

Ensuring the appropriate utilization of system resources using weighted workload based, time-independent scheduling, including: receiving an I/O request associated with an entity; determining whether an amount of system resources required to service the I/O request is greater than an amount of available system resources in a storage system; responsive to determining that the amount of system resources required to service the I/O request is greater than the amount of available system resources in the storage system: queueing the I/O request in an entity-specific queue for the entity; detecting that additional system resources in the storage system have become available; and issuing an I/O request from an entity-specific queue for an entity that has a highest priority, where a priority for each entity is determined based on the amount of I/O requests associated with the entity and a weighted proportion of resources designated for use by the entity.