Method and apparatus for synchronizing selected logical partitions of a partitioned information handling system to an external time reference
US6209106A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1998 |
| Grant date | Mar 27, 2001 |
| Priority date | — |
| Expiry date | Sep 30, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F1/04
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for specifying offsets from an external time reference (ETR) for selected logical partitions of a partitioned information handling system. Each logical partition has a logical time-of-day (TOD) clock which may be set independently of the host system clock by specifying an epoch offset from the host clock. A system operator is presented with a display panel in which the operator may specify the magnitude and sign of an ETR offset for each logical partition selected to have an ETR offset. Each logical partition, upon being activated, issues a Store Clock (STCK) instruction to read its own logical TOD clock as well as a Store ETR (STETR) instruction to read the ETR. If the logical partition has a specified ETR offset, the logical partition manager simulates the STETR instruction by adding or subtracting the ETR offset to the real ETR time and returning the modified value to the partition; otherwise, the logical partition manager returns the real ETR time to the partition. If the read ETR time (as returned by the STETR instruction) differs from the read logical clock time, the logical partition issues a Set Clock (SCK) instruction to reset the logical partition c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.