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Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

1995

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Syracuse University

Northeast Parallel Architecture Center

Articles 1 - 12 of 12

Full-Text Articles in Physical Sciences and Mathematics

Runtime And Language Support For Compiling Adaptive Irregular Programs On Distributed Memory Machines, Yuan-Shin Hwang, Bongki Moon, Shamik D. Sharma, Ravi Ponnusamy Jan 1995

Runtime And Language Support For Compiling Adaptive Irregular Programs On Distributed Memory Machines, Yuan-Shin Hwang, Bongki Moon, Shamik D. Sharma, Ravi Ponnusamy

Northeast Parallel Architecture Center

In many scientific applications, arrays containing data are indirectly indexed through indirection arrays. Such scientific applications are called irregular programs and are a distinct class of applications that require special techniques for parallelization. This paper presents a library called CHAOS, which helps users implement irregular programs on distributed-memory message-passing machines, such as the Paragon, Delta, CM-5 and SP-1. The CHAOS library provides efficient runtime primitives for distributing data and computation over processors; it supports efficient index translation mechanisms and provides users high-level mechanisms for optimizing communication. CHAOS subsumes the previous PARTI library and supports a larger class of applications. In …

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Communication Strategies For Out-Of-Core Programs On Distributed Memory Machines, Rajesh Bordawekar, Alok Choudhary Jan 1995

Communication Strategies For Out-Of-Core Programs On Distributed Memory Machines, Rajesh Bordawekar, Alok Choudhary

Northeast Parallel Architecture Center

In this paper, we show that communication in the out-of-core distributed memory problems requires both inter-processor communication and file I/O. Given that primary data structures reside in files, even communication requires I/O. Thus, it is important to optimize the I/O costs associated with a communication step. We present three methods for performing communication in out-of-core distributed memory problems. The first method, termed as the “out-of-core“communication method, follows a loosely synchronous model. Computation and Communication phases in this case are clearly separated, and communication requires permutation of data in files. The second method, termed as”demand-driven-in-core communication” considers only communication required of …

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Supporting Irregular Distributions Using Data-Parallel Languages, Ravi Ponnusamy, Yuan-Shin Hwang, Raja Das, Alok Choudhary, Geoffrey Fox Jan 1995

Supporting Irregular Distributions Using Data-Parallel Languages, Ravi Ponnusamy, Yuan-Shin Hwang, Raja Das, Alok Choudhary, Geoffrey Fox

Northeast Parallel Architecture Center

Languages such as Fortran D provide irregular distribution schemes that can efficiently support irregular problems. Irregular distributions can also be emulated in HPF. Compilers can incorporate runtime procedures to automatically support these distributions.

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Parallel Remapping Algorithms For Adaptive Problems, Chao Wei Ou, Sanjay Ranka Jan 1995

Parallel Remapping Algorithms For Adaptive Problems, Chao Wei Ou, Sanjay Ranka

Northeast Parallel Architecture Center

In this paper we present fast parallel algorithms for remapping a class of irregular and adaptive problems on coarse-grained distributed memory machines. We show that the remapping of these applications, using simple index-based mapping algorithm, can be reduced to sorting a nearly sorted list of integers or merging an unsorted list of integers with a sorted list of integers. By using the algorithms we have developed, the remapping of these problems can be achieved at a fraction of the cost of mapping from scratch. Experimental results are presented on the CM-5.

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Software Tool Evaluation Methodology, Salim Hariri, Sung Yong Park, Rajashekar Reddy, Mahesh Subramanyan Jan 1995

Software Tool Evaluation Methodology, Salim Hariri, Sung Yong Park, Rajashekar Reddy, Mahesh Subramanyan

Northeast Parallel Architecture Center

The recent development of parallel and distributed computing software has introduced a variety of software tools that support several programming paradigms and languages. This variety of tools makes the selection of the best tool to run a given class of applications on a parallel or distributed system a non-trivial task that requires some investigation. We expect tool evaluation to receive more attention as the deployment and usage of distributed systems increases. In this paper, we present a multi-level evaluation methodology for parallel/distributed tools in which tools are evaluated from different perspectives. We apply our evaluation methodology to three message passing …

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Cluster Computing Review, Mark Baker, Geoffrey C. Fox, Hon W. Yau Jan 1995

Cluster Computing Review, Mark Baker, Geoffrey C. Fox, Hon W. Yau

Northeast Parallel Architecture Center

In the past decade there has been a dramatic shift from mainframe or ‘host−centric’ computing to a distributed ‘client−server’ approach. In the next few years this trend is likely to continue with further shifts towards ‘network−centric’ computing becoming apparent. All these trends were set in motion by the invention of the mass−reproducible microprocessor by Ted Hoff of Intel some twenty−odd years ago. The present generation of RISC microprocessors are now more than a match for mainframes in terms of cost and performance. The long−foreseen day when collections of RISC microprocessors assembled together as a parallel computer could out perform the …

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High Performance Fortran And Possible Extensions To Support Conjugate Gradient Algorithms, K. Dincer, Ken Hawick, Alok Choudhary, Geoffrey C. Fox Jan 1995

High Performance Fortran And Possible Extensions To Support Conjugate Gradient Algorithms, K. Dincer, Ken Hawick, Alok Choudhary, Geoffrey C. Fox

Northeast Parallel Architecture Center

We evaluate the High-Performance Fortran (HPF) language for the compact expression and efficient implementation of conjugate gradient iterative matrix-solvers on High Performance Computing and Communications(HPCC) platforms. We discuss the use of intrinsic functions, data distribution directives and explicitly parallel constructs to optimize performance by minimizing communications requirements in a portable manner. We focus on implementations using the existing HPF definitions but also discuss issues arising that may influence a revised definition for HPF-2. Some of the codes discussed are available on the World Wide Web at http://www.npac.syr.edu/hpfa/ alongwith other educational and discussion material related to applications in HPF.

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The Use Of The National Information Infrastructure And High Performance Computers In Industry, Geoffrey C. Fox, Wojtek Furmanski Jan 1995

The Use Of The National Information Infrastructure And High Performance Computers In Industry, Geoffrey C. Fox, Wojtek Furmanski

Northeast Parallel Architecture Center

We divide potential NII (National Information Infrastructure) services into five broad areas: Collaboration and televirtuality; InfoVISiON (Information, Video, Imagery, and Simulation on Demand), and digital libraries; commerce; metacomputing; WebTop productivity services. The latter denotes the broad suite of tools we expect to be offered on the Web in a general environment we term WebWindows. We review current and future World Wide Web technologies, which could underlie these services. In particular, we suggest an integration framework WebWork for High Performance (parallel and distributed) computing and the NII. We point out that pervasive WebWork and WebWindows technologies will enable, facilitate and substantially …

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Exploiting High Performance Fortran For Computational Fluid Dynamics, Volume 919, Ken Hawick, Geoffrey C. Fox Jan 1995

Exploiting High Performance Fortran For Computational Fluid Dynamics, Volume 919, Ken Hawick, Geoffrey C. Fox

Northeast Parallel Architecture Center

We discuss the High Performance Fortran data parallel programming language as an aid to software engineering and as a tool for exploiting High Performance Computing systems for computational uid dynamics applications. We discuss the use of intrinsic functions, data distribution directives and explicitly parallel constructs to optimize performance by minimizing communications requirements in a portable manner. In particular we use an implicit method such as the ADI algorithm to illustrate the major issues. We focus on regular mesh problems, since these can be efficiently represented by the existing HPF definition, but also discuss issues arising from the use of irregular …

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A Multithreaded Message Passing Environment For Atm Lan/Wan, Rajesh Yadav, Rajashekar Reddy, Salim Hariri, Geoffrey C. Fox Jan 1995

A Multithreaded Message Passing Environment For Atm Lan/Wan, Rajesh Yadav, Rajashekar Reddy, Salim Hariri, Geoffrey C. Fox

Northeast Parallel Architecture Center

Large scale High Performance Computing and Communication (HPCC) applications (e.g. Video-on-Demand, and HPDC) would require storage and processing capabilities which are beyond existing single computer systems. The current advances in networking technology (e.g. ATM) have made high performance network computing an attractive computing environment for such applications. However, using only high speed network is not sufficient to achieve high performance distributed computing environment unless some hardware and software problems have been resolved. These problems include the limited communication bandwidth available to the application, high overhead associated with context switching, redundant data copying during protocol processing and lack of support to …

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High Performance Distributed Computing, Geoffrey C. Fox Jan 1995

High Performance Distributed Computing, Geoffrey C. Fox

Northeast Parallel Architecture Center

High Performance Distributed Computing (HPDC) is driven by the rapid advance of two related technologies -- those underlying computing and communications, respectively. These technology pushes are linked to application pulls, which vary from the use of a cluster of some 20 workstations simulating fluid flow around an aircraft, to the complex linkage of several hundred million advanced PCs around the globe to deliver and receive multimedia information. The review of base technologies and exemplar applications is followed by a brief discussion of software models for HPDC, which are illustrated by two extremes -- PVM and the conjectured future World Wide …

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Basic Issues And Current Status Of Parallel Computing -- 1995, Geoffrey C. Fox Jan 1995

Basic Issues And Current Status Of Parallel Computing -- 1995, Geoffrey C. Fox

Northeast Parallel Architecture Center

The best enterprises have both a compelling need pulling them forward and an innovative technological solution pushing them on. In high-performance computing, we have the need for increased computational power in many applications and the inevitable long-term solution is massive parallelism. In the short term, the relation between pull and push may seem unclear as novel algorithms and software are needed to support parallel computing. However, eventually parallelism will be present in all computers -- including those in your children's video game, your personal computer or workstation, and the central supercomputer.

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