Patent · US Expired

Equal access to prevent gateword dominance in a multiprocessor write-into-cache environment

US6970977B2 · kind B2 · utility

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4References
6Claims
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Key dates

Filing dateMar 31, 2003
Grant dateNov 29, 2005
Priority date
Expiry dateJan 19, 2024

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F12/084
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

In a multiprocessor write-into-cache data processing system including: a memory; at least first and second shared caches; a system bus coupling the memory and the shared caches; at least one processor having a private cache coupled, respectively, to each shared cache; method and apparatus for preventing hogging of ownership of a gateword stored in the memory which governs access to common code/data shared by processes running in the processors by which a read copy of the gateword is obtained by a given processor by performing successive swap operations between the memory and the given processor's shared cache, and the given processor's shared cache and private cache. If the gateword is found to be OPEN, it is CLOSEd by the given processor, and successive swap operations are performed between the given processor's private cache and shared cache and shared cache and memory to write the gateword CLOSEd in memory such that the given processor obtains exclusive access to the governed common code/data. When the given processor completes use of the common code/data, it writes the gateword OPEN in its private cache, and successive swap operations are performed between the given processor's…

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