Optimizing I/O latency by software stack latency reduction in a cooperative thread processing model

An apparatus, comprising:

• a memory;
• and
• a processing circuitry operatively coupled to the memory, the processing circuitry being configured to perform the operations of:
• instantiating a first poller for detecting whether pending storage device operations have been completed;
• executing the first poller to identify a first storage device operation that has been completed, wherein executing the first poller includes:
• (a) executing a first function to detect whether a completion queue corresponding to a storage device driver is empty, the first function being arranged to read a content of a memory location that is associated with the completion queue, the first function being executed in a user space of the storage node, (b) terminating the execution of the first poller when the completion queue is empty, and (c) executing a system call function to the storage device driver only when the completion queue is not empty, wherein the system call function is executed in a kernel space of the storage node, and the system call function is configured to identify one or more operations that are listed in the completion queue;
• identifying a first thread that is waiting for the first storage device operation to be completed;
• and
• transitioning the first thread from a waiting state to a ready state.

A non-transitory computer-readable medium storing one or more processor-executable instructions, which when executed by a processing circuitry of a storage node cause the processing circuitry to perform the operations of:

• instantiating a first poller for detecting whether pending storage device operations have been completed;
• executing the first poller to identify a first storage device operation that has been completed, wherein executing the first poller includes:
• (a) executing a first function to detect whether a completion queue corresponding to a storage device driver is empty, the first function being arranged to read a content of a memory location that is associated with the completion queue, the first function being executed in a user space of the storage node, (b) terminating the execution of the first poller when the completion queue is empty, and (c) executing a system call function to the storage device driver when the completion queue is not empty, wherein the first poller is configured to execute the system call function only when the completion queue is not empty, the system call function is executed in a kernel space of the storage node, and the system call function is configured to identify one or more operations that are listed in the completion queue;
• identifying a first thread that is waiting for the first storage device operation to be completed;
• and
• transitioning the first thread from a waiting state to a ready state.