MEMORY ACCESS METHOD AND INFORMATION PROCESSING APPARATUS

摘要

An information processing apparatus, to which a plurality of nodes each having a processor, a main storage and a temporary storage are connected, stores, into a directory provided in each node, taken-out information indicating that data has been taken out from the node to the temporary storage of another node. If it is determined that a cache error has occurred in a memory access to the temporary storage of a local node and that the memory access is addressed to the main storage of the local node, then the directory of the local node is searched to determine whether a directory hit has occurred. If it is determined that no directory hit has occurred, then the memory access is performed in the local node. If it is determined that the memory access is not addressed to the main storage of the local node or that a directory hit has occurred, then a global snoop processing, which performs a snoop to all nodes, is done by the local node to the other ones.