Patent ID: 8316365

Claim:
A computer system comprising: a plurality of physical CPUs; a plurality of LPARs to each of which any of said physical CPUs is allocated in a dedicated manner and which execute programs under their corresponding guest OSes; management means that manages a plurality of said LPARs and allocates shared processing which is demanded by all LPARs to the plurality of physical CPUs; a guest OS monitoring unit capable of grasping the states of the guest OSes running on said LPARs; and a dispatcher unit that allocates one of said physical CPUs to shared processing requested by said management means having a higher priority than the processing of said LPARs, wherein said dispatcher unit includes a counter that manages the number of times each one of said physical CPUs is allocated to shared processing, wherein said dispatcher unit dispatches the shared processing to the physical CPUs which has the smallest value of said counter when a request for shared processing arises, wherein said dispatcher unit obtains from said guest OS monitoring unit, the state of the LPAR running on the physical CPU that has been allocated to the shared processing, when said LPAR is in idle state, chooses not to update the contents of said counter; and when said LPAR is not in idle state, chooses to update the contents of said counter.