Apparatus and method for pre-fetching data to cached memory using persistent historical page table data
US7099999B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 30, 2003 |
| Grant date | Aug 29, 2006 |
| Priority date | — |
| Expiry date | Oct 26, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2212/654
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A computer system includes a main memory, at least one processor, and at least one level of cache. The system maintains reference history data with respect to each addressable page in memory, preferably in a page table. The reference history data is preferably used to determine which cacheable sub-units of the page should be pre-fetched to the cache. The reference history data is preferably an up or down counter which is incremented if the cacheable sub-unit is loaded into cache and is referenced by the processor, and decremented if the sub-unit is loaded into cache and is not referenced before being cast out. The reference counter thus expresses an approximate likelihood, based on recent history, that the sub-unit will be referenced in the near future.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.