Patent ID: 7590686
Filing Date: 2009-09-15
Classification: G06F

Abstract:
1. An apparatus for controlling a multi-processor system, which is designed for use in a scalable multi-processor system having a plurality of nodes and which is provided in each node to perform a process on a data request, said apparatus comprising: a plurality of local ports to hold data request made from the node; a local snoop unit to perform a local snoop on the requests held in the local ports; a broadcast queue to hold the request subjected to the local snoop and broadcasts the request to other nodes when the local snoop fails to process requested data; a plurality of global ports to hold requests broadcast from the other nodes; a global snoop unit to perform a global snoop on the requests held in the global ports; and a plurality of retry-mode control units that have a global retry mode and a local retry mode, and switch from one of the global retry mode and the local retry mode to the other in accordance with a prescribed condition, so that a retry instruction is issued to the global ports in the global retry mode or to the local ports in the local retry mode when the global snoop fails to process the requested data.