Patent ID: 8566523

Claim:
A cache consistency management device, comprising: a ping-pong monitoring unit configured to monitor a ping-pong migration sequence generated between a plurality of processors; a counting unit configured to count a number of successive generations of the ping-pong migration sequence in response to the monitoring result; and a request modifying unit configured to modify a migration request to a request of a non-migratory sharing method on the basis of the counting result, wherein the ping-pong migration sequence includes three sequential state transitions performed by requests provided from the plurality of processors, the three sequential state transitions including, in order, a transition from a first state to a second state, a transition from the second state to a third state, and a transition from the third state back to the first state, and wherein the transition from the first state to the second state takes place upon detection of a migration request between the plurality of processing units, the transition from the second state to the third state takes place upon detection of a shared request between the plurality of processing units, and the transition from the third state back to the first state takes place upon detection of an invalidate request between the plurality of processing units.