摘要 |
MULTIPLE I/O BUS VIRTUAL BROADCAST OF PROGRAMMED I/O INSTRUCTIONS A method for performing an input/output process containing a programmed input/output (PIO) instruction in a multiprocessor system including at least two processors each having an associated I/O bus with I/O devices connected thereto. The method comprises the steps of storing a unique address and a bus location for each I/O device in a device location table, determining the address of a referenced I/O device prior to performing the PIO instruction, reading the corresponding I/O bus location of the referenced I/O device from the device location table and executing the input/output process on the prescribed processor associated with the I/O bus to which the referenced I/O device is located. The method is used in conjunction with a task scheduler including a process control block for each scheduled process. When the PIO instruction references a device on the local I/O bus, the input/output process is executed normally. To execute the input/output process on a remote processor, a locked descriptor identifying the remote processor is placed in the process control block for that process. The input/output process 18 then scheduled for execution on the remote processor. |