INPUT/OUTPUT PROCESSING SYSTEM

摘要

PROBLEM TO BE SOLVED: To reduce the competition of accesses to an I/O instruction processing queue control table (UCWC) between an instruction processor(IP) and an I/O processor(IOP). SOLUTION: The I/O processing system is provided with 2nd processing queue control tables (L-UCWCs) 80, 81 to be used only for respective IOPs 30, 31. When an I/O instruction is generated, an IP 1 registers an I/O control table (UCW) corresponding to I/O specified by the I/O instruction in the UCWC corresponding to the IOP for processing the I/O instruction. Each of the IOPs 30, 31 copies the UCWC corresponding to the IOP itself to its own L-UCWC. clears the UCWC and executes the processing of the I/O instruction by using the L-UCWC.