Sponsor
Portland State University. Department of Electrical and Computer Engineering
First Advisor
Michael A. Driscoll
Term of Graduation
Winter 1999
Date of Publication
3-12-1999
Document Type
Thesis
Degree Name
Master of Science (M.S.) in Electrical and Computer Engineering
Department
Electrical and Computer Engineering
Language
English
Subjects
Computer interfaces, High performance computing, Cache memory
DOI
10.15760/etd.5858
Physical Description
1 online resource (vi, 112 pages)
Abstract
As the number of NUMA system's cache coherency protocols based on the IEEE Std. 1596-1992, Standard for Scalable Coherent Interface (SCI) Specification increases, it is important to review this complex protocol to determine if the protocol can be enhanced in any way. This research provides two realizable extensions to the standard SCI cache protocol. Both of these extensions lie in the basic confines of the SCI architectures.
The first extension is a simplification to the SCI protocol in the area of prepending to a sharing list. Depending if the cache line is marked "Fresh" or "Gone", the flow of events is distinctly different. The guaranteed forward progress extension is a simplification to the SCI protocol in this area; making the act of prepending to an existing sharing list independent of whether the line is in the "Fresh" or "Gone" state. In addition, this extension eliminates the need for SCI command, as well as distributes the resource requirements of supplying data of a shared line equally among all nodes of the sharing list. The second extension addresses the time to purge (or invalidate) an SCI sharing list. This extension provides a realizable solution that allows the node being invalidated to acknowledge the request prior to the completion of the invalidation while maintaining the memory consistency model of the processors of the system.
The resulting cache protocol was developed and implemented for Sequent Computer System Inc. NUMA-Q system. The cache protocol was run on systems ranging from eight to sixty four processors and provided between 7% and 20% reduction in time to invalidate an SCI sharing list.
Rights
In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
Persistent Identifier
https://archives.pdx.edu/ds/psu/22666
Recommended Citation
Safranek, Robert J., "Enhancements to the Scalable Coherent Interface Cache Protocol" (1999). Dissertations and Theses. Paper 3977.
https://doi.org/10.15760/etd.5858
Comments
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