Abstract:
Cache coherency rules for a multi-processor computing system that is capable of working with compressed cache lines' worth of information are described. A multi-processor computing system that is capable of working with compressed cache lines' worth of information is also described. The multi-processor computing system includes a plurality of hubs for communicating with various computing system components and for compressing/decompressing cache lines' worth of information. A processor that is capable of labeling cache lines' worth of information in accordance with the cache coherency rules is described. A processor that includes a hub as described above is also described.
Abstract:
The cache coherency protocol described herein can be used to maintain a virtual model of a system, where the virtual model does not change as the system configuration changes. In general, the virtual model is based on the assumption that each node in the system can directly communicate with some number of other nodes in the system. In one embodiment, for each cache line, the address of the cache line is used to designate a node as the “home” node and all other nodes as “peer” nodes. The protocol specifies one set of messages for communication with the line's home node and another set of messages for communication with the line's peer nodes.