Processor including replay queue to break livelocks
US6785803B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 2000 |
| Grant date | Aug 31, 2004 |
| Priority date | — |
| Expiry date | Jul 21, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/3869
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A technique is provided for breaking a stalled condition or livelock in a processor having a replay queue. A livelock or stalled condition is detected. One or more instructions are temporarily stored in a replay queue. A release or break in the livelock or stalled condition is detected, and the instructions are then unloaded from the replay queue for replay or re-execution. For a multi-threaded processor, a stall is detected in one of the threads. Instructions of the stalled thread are temporarily stored in a replay queue, except the oldest instruction of the stalled thread which is allowed to replay or re-execute. This allows other threads to have access to execution and replay resources. Eventually, the oldest instruction will execute and retire, which breaks or releases the stalled thread. The instructions stored in the replay queue are then unloaded from the replay queue.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.