DISPATCHING CONTROL SYSTEM FOR VIRTUAL COMPUTER

摘要

PURPOSE:To reduce an overhead by selecting and starting a virtual processor that is run next based on the running priority designated by a VMCP. CONSTITUTION:A PSW 8 is set under a waiting state by an OS on a running virtual processor. In other words, an instruction which sets a wait bit 9 at '1' is outputted to an instruction executing circuit 4 via a line 100. Thus the bit 9 of the PSW 8 is set at '1' via a line 101 in case said instruction can be executed directly by the circuit 4 and an instruction executing microprogram 12. Then a virtual processor state saving mechanism 10 is started by a line 102 to save the state of a virtual processor together with a virtual processor state saving microprogram 11. Thus it is possible to drive the virtual processor that satisfies the running conditions with an inactive processors excepting for the corresponding processor.