METHOD AND SYSTEM FOR EFFICIENT I/O OPERATION COMPLETION IN A FIBRE CHANNEL NODE USING AN APPLICATION SPECIFIC INTEGRATION CIRCUIT AND DETERMINING I/O OPERATION COMPLETION STATUS WITHIN INTERFACE CONTROLLER

摘要

A method and system for enhancing the efficiency of the completion of host-initiated I/O operations within a fiber channel node. The host computer component of the fiber channel node does not allocate the memory buffer for the FCP response frame received by the FC node at the completion of an I/O operation. Instead, the interface controller of the FC node processes FCP response frames in order to determine whether or not an I/O operation successfully completes. In the common case that the I/O operation successfully completes, the interface controller writes the FCP exchange ID corresponding to the I/O operation to a special location in memory which serves to invoke logic functions implemented in an ASIC that de-allocate host memory resources allocated for the I/O operation. In the uncommon cases in which I/O operations fail, the interface controller queues the FCP response frame retrieved from a target node to a host memory queue and queues a completion message to a second host memory queue causing the host computer to field an interrupt and handle any error conditions and memory deallocation functionality required in order to complete the I/O operation.