Space-efficient expected access time algorithm for hard disk drive command queue ordering
US6725327B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 14, 2000 |
| Grant date | Apr 20, 2004 |
| Priority date | — |
| Expiry date | Sep 7, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0676
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus are provided for hard disk drive command queue ordering. For each command in the hard disk drive command queue, an expected access time is calculated including a probability of success calculation. A command in the hard disk drive command queue having a minimum calculated expected access time is identified. Then the identified command having a minimum calculated expected access time is executed. For an estimated seek time of less than a time for one full revolution, a probability of a miss multiplied by a time of one extra revolution is calculated and the result is added to an estimated seek time to provide the expected access time. For an estimated seek time of greater than a time for one full revolution, a probability of a make multiplied by a time of one extra revolution is calculated and the result is subtracted from an estimated seek time to provide the expected access time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.