Transfer request queue control system using flags to indicate transfer

Abstract

A transfer request queue control system for a parallel computer system includes a plurality of processing units each having a main storage storing instructions and data. An instruction processor reads the instructions from the main storage and executes the instructions. A transfer processor performs data transfers in packets, each comprising a header and body data and each data transfer comprising one or more packets. A network couples transmitting and receiving processing units, which are to perform a data transfer based on information included in the header of each packet, the header information being related to a destination of the data, an attribute of a memory access to the main storage and a length of the data. The transfer processor performs parallel processing by making a data transfer between the main storage and the network in successive packets, depending on the attribute of the memory access. The transfer processor of one of the processing units comprises a transfer request queue comprising a list of headers of respective packets corresponding to each of plural requested data transfers, a managing part for managing a transfer queue valid flag which indicates validity of a transfer request of the transfer request queue and a control part for performing a data transfer in response to a data transfer request and based on the transfer queue valid flag.