Decentralized global coherency management in a multi-node computer system

摘要

A non-uniform memory access (NUMA) computer system includes a first node and a second node coupled by a node interconnect. The second node includes a local interconnect, a node controller coupled between the local interconnect and the node interconnect, and a controller coupled to the local interconnect. In response to snooping an operation from the first node issued on the local interconnect by the node controller, the controller signals acceptance of responsibility for coherency management activities related to the operation in the second node, performs coherency management activities in the second node required by the operation, and thereafter provides notification of performance of the coherency management activities. To promote efficient utilization of queues within the node controller, the node controller preferably allocates a queue to the operation in response to receipt of the operation from the node interconnect and then deallocates the queue in response to transferring responsibility for coherency management activities to the controller.