A multiprocessing computer system employing local and global address spaces and multiple access modes

摘要

A multiprocessing computer system employing local and global address spaces and multiple access modes. A processor within a node may initiate a transaction which requires inter-node communication. A local address may be translated to a global address. When a request is sent by a requesting node to a home node, the home node sends read and/or invalidate demands to any slave nodes holding cached copies of the requested data. The demands from the home node to the slave nodes may each advantageously include a value indicative of the number of replies the requesting agent should expect to receive. The slaves reply back to the requesting node with either data or an acknowledge. Each reply may further include the number of replies the requester should expect. Upon receiving all expected replies, the requesting node may send a completion message back to the home and may treat the transaction as completed and proceed with subsequent processing.