Bandwidth reduction technique in a snooping-based cache-coherent cluster of multiprocessing nodes
US7315919B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 15, 2004 |
| Grant date | Jan 1, 2008 |
| Priority date | — |
| Expiry date | Oct 18, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0817
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A cluster of multiprocessing nodes uses snooping-based cache-coherence to maintain consistency among the cache memories of the multiprocessing nodes. One or more of the multiprocessing nodes each maintain a directory table that includes a list of addresses of data last transferred by cache-to-cache transfer transactions. Thus, upon a local cache miss for requested data, a multiprocessing node searches its directory table for an address of the requested data, and if the address is found in the directory table, the multiprocessing node obtains a copy of the requested data from the last destination of the requested data as indicated in the directory table. Thereafter, a message indicating the completion of a cache-to-cache transfer is broadcast to other connected multiprocessing nodes on a “best efforts” basis in which messages are relayed from multiprocessing node to multiprocessing node using low priority status and/or otherwise unused cycles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.