Multiprocessing system configured to detect and efficiently provide for migratory data access patterns
US5734922A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1996 |
| Grant date | Mar 31, 1998 |
| Priority date | — |
| Expiry date | Jul 1, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2212/272
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A computer system includes a directory at each node which stores coherency information for the coherency units for which that node is the home node. In addition, the directory stores a data access state corresponding to each coherency unit which indicates the data access pattern observed for that coherency unit. The data access state may indicate migratory or non-migratory data access patterns. If the coherency unit has been observed to have a migratory data access pattern, then read/write access rights are granted. Conversely, if the coherency unit has been observed to have non-migratory data access patterns, then read access rights are granted. The home node further detects the migratory and non-migratory data access patterns and selects transitions between the migratory and non-migratory data access states independent of the cache hierarchies within the nodes which access the affected coherency unit. In one embodiment, a pair of counters are employed for each coherency unit. One of the counters is incremented when the coherency unit is in the migratory data access state and a data migration is detected. The other counter is incremented when the coherency unit is in the non-migra…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.