Apparatus and method for managing work and completion queues using head and tail pointers
US6725296B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 26, 2001 |
| Grant date | Apr 20, 2004 |
| Priority date | — |
| Expiry date | Oct 10, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/4806
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An apparatus and method for managing work and completion queues using head and tail circular pointers. With the apparatus and method, queue head and tail pointers are maintained in the channel interface and the host channel adapter. The head and tail pointers in the host channel adapter include a queue pointer table index and a queue page index for identifying a position within the queue. For work queues, the tail pointer in the channel interface is used to identify a next position where a work queue entry may be written. The head pointer in the channel interface is used only to determine whether the work queue is full or not. The head pointer in the host channel adapter is used to identify a next work queue entry for processing by the host channel adapter. The tail pointer in the host channel adapter is used by the host channel adapter to determine if the queue is empty. For completion queues, the head pointer in the channel interface is used to identify a next completion queue entry to be processed. The tail pointer in the host channel adapter is used to identify a next position in the completion queue to which the host channel adapter may post a completion queue entry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.