Patent ID: 6279084
Filing Date: 2001-08-21
Classification: G06F

Abstract:
A method of serializing local and remote references directed to a shared memory to provide coherency between the local and remote references in a switch based multi-processor system in which the local and remote references can occur concurrently, the multi-processor system having a plurality of nodes, each node having a plurality of processors and a portion of the shared memory, the shared memory divided among the plurality of nodes, the method comprising the steps of:coupling the plurality of nodes to a hierarchical switch to enable communication among the nodes;forwarding subsequent local references directed to a portion of the shared memory by the node to the hierarchical switch if a previous local reference to the portion of the shared memory has been previously forwarded to the hierarchical switch by the node;providing a directory for each node to provide a serialization point for the local references to be forwarded to the hierarchical switch by causing the local references to access the directory serially resulting in the local references being ordered;providing a queue to store the ordered local references; andcoupling a serial bus to the queue wherein the local references are sent from the queue via the serial bus to the hierarchical switch in the order stored in the queue and the hierarchical switch resending the local references along with the remote references to the portion of the shared memory, the hierarchical switch maintaining the order of the local references received.