Patent · US Active

Read-copy update grace period detection without atomic instructions that gracefully handles large numbers of processors

US7454581B2 · kind B2 · utility

52Cited by
6References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 27, 2004
Grant dateNov 18, 2008
Priority date
Expiry dateOct 20, 2026

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S707/99957
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A method for avoiding unnecessary grace period token processing while detecting a grace period without atomic instructions in a read-copy update subsystem or other processing environment that requires deferring removal of a shared data element until pre-existing references to the data element are removed. Detection of the grace period includes establishing a token to be circulated between processing entities sharing access to the data element. A grace period elapses whenever the token makes a round trip through the processing entities. A distributed indicator associated with each processing entity indicates whether there is a need to perform removal processing on any shared data element. The distributed indicator is processed at each processing entity before the latter engages in token processing. Token processing is performed only when warranted by the distributed indicator. In this way, unnecessary token processing can be avoided when the distributed indicator does not warrant such processing.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.