Multiprocessor system with cache/disk subsystem with status routing for

Abstract

In a data processing system having plural disk devices connected to first and second storage control units, and plural processors connected to the storage control units by connection paths, a table is provided having entries defining the connection paths between each storage control unit and each processor. The storage control units may queue commands from the processors in a command queue for later execution. Either storage control unit may utilize a queued command to issue a seek signal to a disk device and report status to the processor which issued the command. When a disk device completes a seek it issues an interrupt signal which may be sampled by either storage control unit to report further status. In order to report status to the processor which issued the command, a storage control unit searches the table defining the connection paths between the storage control units and the processors and applies the status to the first available connection path that it finds. If one storage control unit, upon searching the table, finds that there is no connection path between itself and the processor which issued the command, it returns to an idle condition so that the other storage control unit may respond to the interrupt signal, search the table, and apply the status indication to the host processor which issued the command.