Increasing the delivered performance of computers by running programs in parallel is an old idea with a new urgency. Multi cores (multi processors) on chips have emerged as a way to increase performance wherever chips...
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ISBN:
(纸本)9781595937957
Increasing the delivered performance of computers by running programs in parallel is an old idea with a new urgency. Multi cores (multi processors) on chips have emerged as a way to increase performance wherever chips are used. the talk will focus on the role programming languages and compilers must play in delivering parallel performance to users and applications. the speaker's personal experiences with languages and compilers for high performance systems will provide the basis for her observations. the talk is intended to encourage the exploration of new approaches.
this paper describes experiments withthe freely available tool Helgrind, results obtained by using it for debugging a server application comprising 500 kLOC. We present improvements to the run time analysis of C++ pr...
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ISBN:
(纸本)1595936025
this paper describes experiments withthe freely available tool Helgrind, results obtained by using it for debugging a server application comprising 500 kLOC. We present improvements to the run time analysis of C++ programs that result in a dramatic reduction of false warnings.
the polyhedral model is a well developed formalism and has been extensively used in a variety of contexts viz. the automatic parallelization of loop programs, program verification, locality, hardware generationand mor...
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ISBN:
(纸本)9781595936028
the polyhedral model is a well developed formalism and has been extensively used in a variety of contexts viz. the automatic parallelization of loop programs, program verification, locality, hardware generationand more recently, in the automatic reduction of asymptotic program complexity. Such analyses and transformations rely on certain closure properties. However, the model is limited in expressivity and the need for a more general class of programs is widely *** provide the extension to ⁰-polyhedra which are the intersection of polyhedra and lattices. We prove the required closure properties using a novel representation and interpretation of ⁰-polyhedra. In addition, we also prove closure in the ⁰-polyhedral model under images by dependence functions---thereby proving that unions of LBLs, widely assumedto be a richer class of sets, is equal to unions of ⁰-polyhedra. Another corollary of this result is the equivalence of the unions of ⁰-polyhedraand Presburger sets. Our representation and closure properties constitute the foundations of the ⁰-polyhedral model. As an example, we presentthe transformation for automatic reduction of complexity in the ⁰-polyhedral model.
In 2002, we first brought High Performance Computing (HPC) methods to the college classroom as a way to enrich Computational Science education. through the years, we have continued to facilitate college faculty in sci...
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ISBN:
(纸本)1595931899
In 2002, we first brought High Performance Computing (HPC) methods to the college classroom as a way to enrich Computational Science education. through the years, we have continued to facilitate college faculty in science, technology, engineering, and mathematics (STEM) disciplines to stay current with HPC methodologies. We have accomplished this by designing and delivering faculty workshops, hosted in a variety of lab settings, as well as by developing tools supporting the technical infrastructure necessary for HPC education, all this without requiring access to traditional HPC computing platforms. In all, we have so far presented 16 professional development workshops for close to 400 predominantly undergraduate STEM faculty. this paper presents the result of internal formative evaluation by workshop instructors and the materials and tools developed during that process. We did this work as part of the National Computational Science Institute (NCSI) and in collaboration withthe following groups: the Minority Serving Institutions - High Performance Computing (MSI-HPC) program of the National Computational Science Alliance the Consortium for Computing Sciences in Colleges (CCSC) the Center for Excellence in High Performance Computing the Oklahoma University Supercomputing symposium series the Super Computing (SC) conference series education program We presented learners with a sequence of interactive, "run it, modify it, build it" open-ended lab exercises drawn from a variety of disciplines. Interactivity means having the ability to change parallel and algorithmic parameters, e.g. running software on more than one machine, using different models, refining the model, changing the problem scale, using different parallel algorithms. there is a lack of scientific parallel curricula suitable for illustrating Computational Science principles in the classroom. We addressed this need by locating, and where necessary creating, suitable open source software, data-sets, and cur
Applications need to become more concurrent to take advantage of the increased computational power provided by chip level multiprocessing. Programmers have traditionally managed this concurrency using locks (mutex bas...
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In 2002, we first brought High Performance Computing (HPC) methods to the college classroom as a way to enrich Computational Science education. through the years, we have continued to facilitate college faculty in sci...
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ISBN:
(纸本)9781595931894
In 2002, we first brought High Performance Computing (HPC) methods to the college classroom as a way to enrich Computational Science education. through the years, we have continued to facilitate college faculty in science, technology, engineering, and mathematics (STEM) disciplines to stay current with HPC methodologies. We have accomplished this by designing and delivering faculty workshops, hosted in a variety of lab settings, as well as by developing tools supporting the technical infrastructure necessary for HPC education, all this without requiring access to traditional HPC computing platforms. In all, we have so far presented 16 professional development workshops for close to 400 predominantly undergraduate STEM faculty. this paper presents the result of internal formative evaluation by workshop instructors and the materials and tools developed during that *** did this work as part of the National Computational Science Institute (NCSI) and in collaboration withthe following groups: the Minority Serving Institutions--High Performance Computing (MSI-HPC) program of the National Computational Science Alliancethe Consortium for Computing Sciences in Colleges (CCSC)the Center for Excellence in High Performance Computingthe Oklahoma University Supercomputing symposium seriesthe Super Computing (SC) conference series education program
Large-scale PC clusters, such as ACSI Lightning with 2,816 processors and the AIST supercluster with more than 3,000 processors, have been constructed. Although software distributed shared memory (S-DSM) provides an a...
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Recently, system architects have built low-power, high-performance clusters, such as Green Destiny. the idea behind these clusters is to improve the energy efficiency of nodes. However, these clusters save power at th...
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ISBN:
(纸本)9781595930804
Recently, system architects have built low-power, high-performance clusters, such as Green Destiny. the idea behind these clusters is to improve the energy efficiency of nodes. However, these clusters save power at the expense of performance. Our approach is instead to use high-performance cluster nodes that are frequency-and voltage-scalable;energy can than be saved by scaling down the CPU. Our prior work has examined the costs and benefits of executing an entire application at a single reduced frequency. this paper presents a framework for executing a single application in several frequency-voltage settings. the basic idea is to first divide programs into phases and then execute a series of experiments, with each phase assigned a prescribed frequency. During each experiment, we measure energy consumption and time and then use a heuristic to choose the assignment of frequency to phase for the next experiment. Our results show that significant energy can be saved without an undue performance penalty;particularly, our heuristic finds assignments of frequency to phase that is superior to any fixed-frequency solution. Specifically, this paper shows that more than half of the NAS benchmarks exhibit a better energy-time tradeoff using multiple gears than using a single gear. For example, IS using multiple gears uses 9% less energy and executes in 1% less time than the closest single-gear solution. Compared to no frequency scaling, multiple gear IS uses 16% less energy while executing only 1% longer. Copyright 2005 acm.
Many learning situations involve separation of labeled training instances by hyperplanes. Consistent separation is of theoretical interest, but the real goal is rather to minimize the number of errors using a bounded ...
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ISBN:
(纸本)3540292438
Many learning situations involve separation of labeled training instances by hyperplanes. Consistent separation is of theoretical interest, but the real goal is rather to minimize the number of errors using a bounded number of hyperplanes. Exact minimization of empirical error in a high-dimensional grid induced into the feature space by axis-parallel hyperplanes is NP-hard. We develop two approximation schemes with performance guarantees, a greedy set covering scheme for producing a consistently labeled grid, and integer programming rounding scheme for finding the minimum error grid with bounded number of hyperplanes.
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