Software-Extended Coherent Shared Memory:Performance and Cost
Abstract This paper evaluates the tradeoffs involved in the design of thesoftware-extended memory system of Alewife, a multiprocessor architecture that implements coherentsharedmemory through a com-bination of hardware and software mechanisms. For each block of memory, Alewife implements between zer...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.70.257 2023-05-15T18:32:44+02:00 Software-Extended Coherent Shared Memory:Performance and Cost The Pennsylvania State University CiteSeerX Archives application/postscript http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.70.257 http://www4.informatik.uni-erlangen.de/~tsthiel/Papers/alewife-coherence-sm.ps.gz en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.70.257 http://www4.informatik.uni-erlangen.de/~tsthiel/Papers/alewife-coherence-sm.ps.gz Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www4.informatik.uni-erlangen.de/~tsthiel/Papers/alewife-coherence-sm.ps.gz text ftciteseerx 2016-01-08T18:51:33Z Abstract This paper evaluates the tradeoffs involved in the design of thesoftware-extended memory system of Alewife, a multiprocessor architecture that implements coherentsharedmemory through a com-bination of hardware and software mechanisms. For each block of memory, Alewife implements between zero and five coherence di-rectory pointers in hardware and allows software to handle requests when the pointers are exhausted. The software includes a flexiblecoherence interface that facilitates protocol software implementation. This interface is indispensable for conducting experimentsand has proven important for implementing enhancements to the basic system. Simulations of a number of applications running on a completesystem (with up to 256 processors) demonstrate that the hybrid architecture with five pointers achieves between 71 % and 100%of full-map directory performance at a constant cost per processing element. Our experience in designing the software protocolinterfaces and experiments with a variety of system configurations lead to a detailed understanding of the interaction of the hardwareand software components of the system. The results show that a small amount of shared memory hardware provides adequate per-formance: One-pointer systems reach between 42 % and 100 % of full-map performance on our parallel benchmarks. A software-only directory architecture with no hardware pointers has lower performance but minimal cost. 1 Introduction Implementing shared memory for a large-scale multiprocessor re-quires balancing the performance of the system as a whole with the complexity and cost of its hardware and software components.Shared memory itself helps control the complexity of the application software written for a machine, but it requires an efficientdesign to achieve this goal. The Alewife architecture[3] uses a combination of hardware and software to provide shared memoryat a constant cost per processing node, without sacrificing performance. Following the integrated systems approach,the architectureuses ... Text The Pointers Unknown |
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Abstract This paper evaluates the tradeoffs involved in the design of thesoftware-extended memory system of Alewife, a multiprocessor architecture that implements coherentsharedmemory through a com-bination of hardware and software mechanisms. For each block of memory, Alewife implements between zero and five coherence di-rectory pointers in hardware and allows software to handle requests when the pointers are exhausted. The software includes a flexiblecoherence interface that facilitates protocol software implementation. This interface is indispensable for conducting experimentsand has proven important for implementing enhancements to the basic system. Simulations of a number of applications running on a completesystem (with up to 256 processors) demonstrate that the hybrid architecture with five pointers achieves between 71 % and 100%of full-map directory performance at a constant cost per processing element. Our experience in designing the software protocolinterfaces and experiments with a variety of system configurations lead to a detailed understanding of the interaction of the hardwareand software components of the system. The results show that a small amount of shared memory hardware provides adequate per-formance: One-pointer systems reach between 42 % and 100 % of full-map performance on our parallel benchmarks. A software-only directory architecture with no hardware pointers has lower performance but minimal cost. 1 Introduction Implementing shared memory for a large-scale multiprocessor re-quires balancing the performance of the system as a whole with the complexity and cost of its hardware and software components.Shared memory itself helps control the complexity of the application software written for a machine, but it requires an efficientdesign to achieve this goal. The Alewife architecture[3] uses a combination of hardware and software to provide shared memoryat a constant cost per processing node, without sacrificing performance. Following the integrated systems approach,the architectureuses ... |
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The Pennsylvania State University CiteSeerX Archives |
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title |
Software-Extended Coherent Shared Memory:Performance and Cost |
spellingShingle |
Software-Extended Coherent Shared Memory:Performance and Cost |
title_short |
Software-Extended Coherent Shared Memory:Performance and Cost |
title_full |
Software-Extended Coherent Shared Memory:Performance and Cost |
title_fullStr |
Software-Extended Coherent Shared Memory:Performance and Cost |
title_full_unstemmed |
Software-Extended Coherent Shared Memory:Performance and Cost |
title_sort |
software-extended coherent shared memory:performance and cost |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.70.257 http://www4.informatik.uni-erlangen.de/~tsthiel/Papers/alewife-coherence-sm.ps.gz |
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http://www4.informatik.uni-erlangen.de/~tsthiel/Papers/alewife-coherence-sm.ps.gz |
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http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.70.257 http://www4.informatik.uni-erlangen.de/~tsthiel/Papers/alewife-coherence-sm.ps.gz |
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