Scientific Software Libraries for Scalable Architectures

Total Page:16

File Type:pdf, Size:1020Kb

Scientific Software Libraries for Scalable Architectures Scientific Software Libraries for Scalable Architectures The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Johnsson, S. Lennart and Kapil K. Mathur. 1994. Scientific Software Libraries for Scalable Architectures. Harvard Computer Science Group Technical Report TR-19-94. Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:25811003 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA Scientic Software Libraries for Scalable Architectures S Lennart Johnsson Kapil K Mathur TR August Parallel Computing Research Group Center for Research in Computing Technology Harvard University Cambridge Massachusetts To app ear in Parallel Scientic Computing SpringerVerlag Scientic Software Libraries for Scalable Architectures S Lennart Johnsson Kapil K Mathur Thinking Machines Corp and Thinking Machines Corp and Harvard University Abstract Massively parallel pro cessors introduce new demands on software systems with resp ect to p erfor mance scalability robustness and p ortability The increased complexity of the memory systems and the increased range of problem sizes for which a given piece of software is used p oses se rious challenges to software developers The Connection Machine Scientic Software Library CMSSL uses several novel techniques to meet these challenges The CMSSL contains routines for managing the data distribution and provides data distribution indep endent functionality High p erformance is achieved through careful scheduling of arithmetic op erations and data mo tion and through the automatic selection of algorithms at runtime We discuss some of the techniques used and provide evidence that CMSSL has reached the goals of p erformance and scalability for an imp ortant set of applications Introduction The main reason for large scale parallelism is p erformance In order for massively parallel architectures to deliver on the promise of extreme p erformance compared to conventional sup er computer architectures an eciency in resource use close to that of conventional sup ercomputers is necessary Achieving high eciency in using a computing system is mostly a question of e cient use of its memory system This is the premise on which the Connection Machine Scientic Software Library the CMSSL is based Another premise for the CMSSL is the notion of scalability Software systems must b e designed to op erate on systems and data sets that may vary in size by as much as four orders of mag nitude This level of scalability with resp ect to computing system size must b e accomplished transparently to the user ie the same program must execute not only correctly but also e ciently without change over this range in pro cessing capacity and corresp onding problem sizes Moreover programs should not have to b e recompiled for various system sizes This requirement will b e even more imp ortant in the future since over time the assignment of pro cessing no des to tasks is exp ected to b ecome much more dynamic than to day Robustness of software b oth with resp ect to p erformance and numerical prop erties are b ecoming increasingly imp ortant The memory system in each no de is b ecoming increasingly complex in order to match the sp eed of the memory system with that of an individual pro cessor The distributed nature of the total memory comp ounds the complexity of the memory system It is imp erative that software systems deliver a large fraction of the available p erformance over a wide range of problem sizes transparently to the user For instance small changes in array sizes should not impact p erformance in a signicant way Robustness with resp ect to p erformance in this sense will increase the demands on the software systems in particular on the runtime parts of the systems Robustness with resp ect to numerical prop erties is also b ecoming increasingly imp ortant The same software may b e used for problem sizes over a very wide range Condition numbers for the largest problems are exp ected to b e signicantly worse than for small problems As a minimum condition estimators must b e provided to allow users to assess the numerical quality of the results It will also b e increasingly necessary to furnish software for illconditione d problems and whenever p ossible automatically choose an appropriate numerical metho d Some parallel metho ds do not have as go o d a numerical b ehavior as sequential metho ds and this disadvantage is often increasing with the degree of parallelism The tradeo b etween p erformance and numerical stability and accuracy is very complex Much research is needed b efore the choice of algorithm with resp ect to numerical prop erties and p erformance can b e automated Portability of co des is clearly highly desirable in order to amortize the software investment over as large a usage as p ossible Portability is also critical in a rapid adoption of new technology thus allowing for early b enets from the increased memory sizes increased p erformance or decreased costp erformance oered by new technology But not all software is p ortable when p erformance is taken into account New architectures like MPPs require new software technology that often lags the hardware technology by several years Thus it is imp ortant to exploit the architecture of software systems such that architecture dep endent nonp ortable software is limited to as few functions as p ossible while maintaining p ortability of the vast amount of application software One of the purp oses of software libraries is to enable p ortability of application co des without loss of p erformance The Connection Machine Scientic Software Library to day has ab out user callable functions covering a wide range of frequent op erations in scientic and engineering computation In this pap er we illustrate how the goals of high p erformance and scalability have b een achieved The outline of the pap er is as follows In the next few sections we discuss memory systems for scalable architectures and their impact on the sequence to storage asso ciation used in mapping arrays to the memory system We then discuss data representations for dense and sparse arrays The memory system and the data representation denes the foundation for the CMSSL We then present the design goals for the CMSSL and how these goals have b een approached and achieved The multipleinstance capability of the CMSSL is an extension of the functionality of conventional libraries in the spirit of array op erations and critical to the p erformance in computations on b oth distributed and lo cal data sets The multipleinstance feature is discussed in Section Scalability and robustness with resp ect to p erformance b oth dep end heavily on the ability to automatically select appropriate schedules for arithmeticlogic op erations and data motion and prop er algorithms These issues are discussed by sp ecic examples A summary is given in Section Architectural mo del High p erformance computing has dep ended on elab orate memory systems since the early days of computing The Atlas introduced virtual memory as a means of making the main relatively slow memory app ear as fast as a small memory capable of delivering data to the pro cessor at its clo ck sp eed Since the emergence of electronic computers pro cessors have as a rule b een faster than memories regardless of the technology b eing used Today most computers conventional sup ercomputers excepted use MOS technology for b oth memories and pro cessors But the prop erties of the MOS technology is such that the sp eed of pro cessors is doubling ab out every months while the sp eed of memories is increasing at a steady rate of ab out yr Since the sp eed of individual memory units to day primarily built out of MOS memory chips is very limited high p erformance systems require a large number of memory banks units even when lo cality of reference can b e exploited High end systems have thousands to tens of MEMORY SYSTEM NETWORK M M M M M M P P P P P P Figure The memory system for distributed memory architectures thousands of memory banks The aggregate memory bandwidth of such systems far exceeds the bandwidth of a bus A network of some form is used to interconnect memory mo dules The no des in the network are typically of a low degree and for most networks indep endent of the size of the network A large variety of network top ologies can b e constructed out of no des with a limited xed degree Massively parallel architectures have employed two and threedimensional mesh top ologies buttery networks binary cub es complete binary trees and fattree top ologies The sp eed of the memory chips present the most severe restriction with resp ect to p erformance The second weakest technological comp onent is the communication system Constructing a communication system with the capacity of a full crossbar with a bandwidth equal to the aggre gate bandwidth of the memory system is not feasible for systems of extreme p erformance and would represent a considerable exp ense even for systems where it may b e technically feasible Hence with a constraint of a network with a lower bandwidth than that of the full memory system in MPPs pro cessors are placed close to the memory mo dules such that whenever lo cal ity of reference can b e exploited the p otential negative impact up on p erformance of the limited
Recommended publications
  • Speeding up Spmv for Power-Law Graph Analytics by Enhancing Locality & Vectorization
    Speeding Up SpMV for Power-Law Graph Analytics by Enhancing Locality & Vectorization Serif Yesil Azin Heidarshenas Adam Morrison Josep Torrellas Dept. of Computer Science Dept. of Computer Science Blavatnik School of Dept. of Computer Science University of Illinois at University of Illinois at Computer Science University of Illinois at Urbana-Champaign Urbana-Champaign Tel Aviv University Urbana-Champaign [email protected] [email protected] [email protected] [email protected] Abstract—Graph analytics applications often target large-scale data-dependent behavior of some accesses makes them hard web and social networks, which are typically power-law graphs. to predict and optimize for. As a result, SpMV on large power- Graph algorithms can often be recast as generalized Sparse law graphs becomes memory bound. Matrix-Vector multiplication (SpMV) operations, making SpMV optimization important for graph analytics. However, executing To address this challenge, previous work has focused on SpMV on large-scale power-law graphs results in highly irregular increasing SpMV’s Memory-Level Parallelism (MLP) using memory access patterns with poor cache utilization. Worse, we vectorization [9], [10] and/or on improving memory access find that existing SpMV locality and vectorization optimiza- locality by rearranging the order of computation. The main tions are largely ineffective on modern out-of-order (OOO) techniques for improving locality are binning [11], [12], which processors—they are not faster (or only marginally so) than the standard Compressed Sparse Row (CSR) SpMV implementation. translates indirect memory accesses into efficient sequential To improve performance for power-law graphs on modern accesses, and cache blocking [13], which processes the ma- OOO processors, we propose Locality-Aware Vectorization (LAV).
    [Show full text]
  • Sparse-Matrix Representation of Spiking Neural P Systems for Gpus
    Sparse-matrix Representation of Spiking Neural P Systems for GPUs Miguel A.´ Mart´ınez-del-Amor1, David Orellana-Mart´ın1, Francis G.C. Cabarle2, Mario J. P´erez-Jim´enez1, Henry N. Adorna2 1Research Group on Natural Computing Department of Computer Science and Artificial Intelligence Universidad de Sevilla Avda. Reina Mercedes s/n, 41012 Sevilla, Spain E-mail: [email protected], [email protected], [email protected] 2Algorithms and Complexity Laboratory Department of Computer Science University of the Philippines Diliman Diliman 1101 Quezon City, Philippines E-mail: [email protected], [email protected] Summary. Current parallel simulation algorithms for Spiking Neural P (SNP) systems are based on a matrix representation. This helps to harness the inherent parallelism in algebraic operations, such as vector-matrix multiplication. Although it has been convenient for the first parallel simulators running on Graphics Processing Units (GPUs), such as CuSNP, there are some bottlenecks to cope with. For example, matrix representation of SNP systems with a low-connectivity-degree graph lead to sparse matrices, i.e. containing more zeros than actual values. Having to deal with sparse matrices downgrades the performance of the simulators because of wasting memory and time. However, sparse matrices is a known problem on parallel computing with GPUs, and several solutions and algorithms are available in the literature. In this paper, we briefly analyse some of these ideas and apply them to represent some variants of SNP systems. We also conclude which variant better suit a sparse-matrix representation. Keywords: Spiking Neural P systems, Simulation Algorithm, Sparse Matrix Representation, GPU computing, CUDA 1 Introduction Spiking Neural P (SNP) systems [9] are a type of P systems [16] composed of a directed graph inspired by how neurons are interconnected by axons and synapses 162 M.A.
    [Show full text]
  • A Framework for Efficient Execution of Matrix Computations
    A Framework for Efficient Execution of Matrix Computations Doctoral Thesis May 2006 Jos´e Ram´on Herrero Advisor: Prof. Juan J. Navarro UNIVERSITAT POLITECNICA` DE CATALUNYA Departament D'Arquitectura de Computadors To Joan and Albert my children To Eug`enia my wife To Ram´on and Gloria my parents Stillicidi casus lapidem cavat Lucretius (c. 99 B.C.-c. 55 B.C.) De Rerum Natura1 1Continual dropping wears away a stone. Titus Lucretius Carus. On the nature of things Abstract Matrix computations lie at the heart of most scientific computational tasks. The solution of linear systems of equations is a very frequent operation in many fields in science, engineering, surveying, physics and others. Other matrix op- erations occur frequently in many other fields such as pattern recognition and classification, or multimedia applications. Therefore, it is important to perform matrix operations efficiently. The work in this thesis focuses on the efficient execution on commodity processors of matrix operations which arise frequently in different fields. We study some important operations which appear in the solution of real world problems: some sparse and dense linear algebra codes and a classification algorithm. In particular, we focus our attention on the efficient execution of the following operations: sparse Cholesky factorization; dense matrix multipli- cation; dense Cholesky factorization; and Nearest Neighbor Classification. A lot of research has been conducted on the efficient parallelization of nu- merical algorithms. However, the efficiency of a parallel algorithm depends ultimately on the performance obtained from the computations performed on each node. The work presented in this thesis focuses on the sequential execution on a single processor.
    [Show full text]
  • Automatic Selection of Sparse Matrix Representation on Gpus
    Automatic Selection of Sparse Matrix Representation on GPUs Naser Sedaghati, Te Mu, Louis-Noël Pouchet, Srinivasan Parthasarathy, P. Sadayappan The Ohio State University Columbus, OH, USA {sedaghat,mut,pouchet,srini,saday}@cse.ohio-state.edu ABSTRACT applications in terms of a dataset-algorithm-platform tri- Sparse matrix-vector multiplication (SpMV) is a core kernel angle. This is a complex relationship that is not yet well in numerous applications, ranging from physics simulation characterized even for much studied core kernels like SpMV. and large-scale solvers to data analytics. Many GPU im- In this paper, we make a first attempt at understanding the plementations of SpMV have been proposed, targeting sev- dataset-algorithm dependences for SpMV on GPUs. eral sparse representations and aiming at maximizing over- The optimization of SpMV for GPUs has been a much re- all performance. No single sparse matrix representation is searched topic over the last few years, including auto-tuning uniformly superior, and the best performing representation approaches to deliver very high performance [22, 11] by tun- varies for sparse matrices with different sparsity patterns. ing the block size to the sparsity features of the computa- In this paper, we study the inter-relation between GPU tion. For CPUs, the compressed sparse row (CSR) – or the architecture, sparse matrix representation and the sparse dual compressed sparse column – is the dominant represen- dataset. We perform extensive characterization of perti- tation, effective across domains from which the sparse ma- nent sparsity features of around 700 sparse matrices, and trices arise. In contrast, for GPUs no single representation their SpMV performance with a number of sparse represen- has been found to be effective across a range of sparse matri- tations implemented in the NVIDIA CUSP and cuSPARSE ces.
    [Show full text]
  • Tridiagonalization of an Arbitrary Square Matrix William Lee Waltmann Iowa State University
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1964 Tridiagonalization of an arbitrary square matrix William Lee Waltmann Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Mathematics Commons Recommended Citation Waltmann, William Lee, "Tridiagonalization of an arbitrary square matrix " (1964). Retrospective Theses and Dissertations. 3829. https://lib.dr.iastate.edu/rtd/3829 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. This dissertation has been 65—3811 microfilmed exactly as received WALTMANN, William Lee, 1934- TRIDIAGONA.LIZATION OF AN ARBITRARY SQUARE MATRIX. Iowa State University of Science and Technology Ph.D., 1964 Mathematics University Microfilms, Inc., Ann Arbor, Michigan TRIDIAGONALIZATION OP AN ARBITRARY SQUARE MATRIX %lliam Lee Waltmann A Dissertation Submitted to the Graduate Faculty in Partial Fulfillment of The Requirements for the Degree of DOCTOR OF PHILOSOPHY Major Subject: Mathematics Approved: Signature was redacted for privacy. In Oharg Signature was redacted for privacy. Head of Major Department Signature was redacted for privacy. Dean of Gradua# College Iowa State University Of Science and Technology Ames, Iowa 1964 il TABLE OP CONTENTS Page I. INTRODUCTION 1 II. KNOW METHODS FOR THE MATRIX EIGENPROBLEM 4 III. KNOm METHODS FOR TRIDIAGONALIZATIOH 11 IV. T-ALGORITHM FOR TRIDIAGONALIZATION 26 V. OBSERVATIONS RELATED TO TRIDIAGONALIZATION 53 VI.
    [Show full text]
  • REPRESENTATIONS of FINITE GROUPS Contents 1. Introduction 1
    REPRESENTATIONS OF FINITE GROUPS SANG HOON KIM Abstract. This paper provides the definition of a representation of a finite group and ways to study it with several concepts and remarkable theorems such as an irreducible representation, the character, and Maschke's Theorem. Contents 1. Introduction 1 2. Group representations 1 3. Important theorems regarding G-invariant Hermitian form and unitary representations 3 4. Irreducible representations and Maschke's Theorem 7 5. Characters 8 6. Permutation representations 12 7. Regular representations 13 8. Schur's Lemma and proof of Orthogonality relations 14 Acknowledgments 18 References 18 1. Introduction Representation theory studies linear operators that are given by group elements acting on a vector space. Thus, representation theory is very useful in that it makes it possible to delve into geometric symmetries effectively with using coordinates, which is not possible if abstract group elements are only considered. This paper assumes that readers prior knowledge of linear algebra, including familiarity with Hermitian form and Spectral Theorem. Moreover, we deal only with finite groups. 2. Group representations We will start with a simple example of a representation of the group T of rotations of a tetrahedron. Suppose that the group T acts on a three-dimensional vector space V . Choose a basis (v1; v2; v3) so that each element of the basis passes through the midpoints A, B, C of three edges as follows. 1 2 SANG HOON KIM v3 C D v B 2 A v1 Figure 1. Tetrahedron on a 3-dimensional space Let x 2 T be the counter clockwise rotation around the vertex D by 2π=3 and y1; y2; y3 2 T be the counter clockwise rotations by π around the vertices A, B, C, respectively.
    [Show full text]
  • A Matrix-Based Approach to Global Locality Optimization
    Appears in Journal of Parallel and Distributed Computing, September 1999 A Matrix-Based Approach to Global Locality Optimization ¡ ¢ £ ¢ Mahmut Kandemir Alok Choudhary J. Ramanujam Prith Banerjee Abstract Global locality optimization is a technique for improving the cache performance of a sequence of loop nests through a combination of loop and data layout transformations. Pure loop transformations are restricted by data dependences and may not be very successful in optimizing imperfectly nested loops and explicitly parallelized programs. Although pure data transformations are not constrained by data dependences, the impact of a data transformation on an array might be program-wide; that is, it can affect all the references to that array in all the loop nests. Therefore, in this paper we argue for an integrated approach that employs both loop and data transformations. The method enjoys the advantages of most of the previous techniques for enhancing locality and is efficient. In our approach, the loop nests in a program are processed one by one and the data layout constraints obtained from one nest are propagated for the optimizing the remaining loop nests. We show a simple and effective matrix-based framework to implement this process. The search space that we consider for possible loop transformations can be represented by general non-singular linear transformation matrices and the data layouts that we consider are those that can be expressed using hyperplanes. Experiments with several floating-point programs on an ¤ -processor SGI Origin 2000 distributed-shared-memory machine demonstrate the efficacy of our approach. Keywords: data reuse, locality, memory hierarchy, parallelism, loop transformations, array restructuring, data trans- formations.
    [Show full text]
  • Data-Parallel Language for Correct and Efficient Sparse Matrix Codes
    Data-Parallel Language for Correct and Efficient Sparse Matrix Codes Gilad Arnold Electrical Engineering and Computer Sciences University of California at Berkeley Technical Report No. UCB/EECS-2011-142 http://www.eecs.berkeley.edu/Pubs/TechRpts/2011/EECS-2011-142.html December 16, 2011 Copyright © 2011, by the author(s). All rights reserved. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission. Data-Parallel Language for Correct and Efficient Sparse Matrix Codes by Gilad Arnold A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Computer Science in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Rastislav Bodík, Chair Professor Koushik Sen Professor Leo A. Harrington Fall 2011 Data-Parallel Language for Correct and Efficient Sparse Matrix Codes Copyright 2011 by Gilad Arnold 1 Abstract Data-Parallel Language for Correct and Efficient Sparse Matrix Codes by Gilad Arnold Doctor of Philosophy in Computer Science University of California, Berkeley Professor Rastislav Bodík, Chair Sparse matrix formats encode very large numerical matrices with relatively few nonzeros. They are typically implemented using imperative languages, with emphasis on low-level optimization. Such implementations are far removed from the conceptual organization of the sparse format, which obscures the representation invariants.
    [Show full text]
  • Complex Conjugation of Group Representations by Inner Automorphlsms
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Complex Conjugation of Group Representations by Inner Automorphlsms Ture Damhus Chemistry Department Z H. C. @sted Institute Universitetsparken 5 DK-2100 Copenhagen 0, Denmark Submitted by Richard A. Brualdi ABSTRACT For finite-dimensional unitary irreducible group representations, theorems are established giving conditions under which the transition from a representation to its complex conjugate may be accomplished by an inner automorphism of the group. The central arguments are of a purely matrix-theoretical nature. Since the investiga- tion naturally falls into two cases according to the Frobenius-Schur classification of irreducible representations, this classification is briefly discussed. INTRODUCTION This paper is concerned with finite-dimensional linear group representa- tions over the field of complex numbers. Given such a representation of a group G, we ask whether it is possible to find an inner automorphism of G carrying the representation into its complex conjugate. It turns out that necessary and sufficient conditions are easily formulated and may be estab- lished using only elementary linear algebra. This is done in Sec. 2. Since the discussion almost immediately splits up into two cases accord- ing to the Frobenius-Schur classification, we give in Sec. 1 a review of this classification. The present investigation was prompted by certain representation-theo- retic problems in the so-called Wigner-Racah algebra of groups, which is of great importance in theoretical chemistry and physics. For these applications we refer the reader to [l] and [16] and references therein.
    [Show full text]
  • Optimization of GPU-Based Sparse Matrix Multiplication for Large Sparse Networks
    2020 IEEE 36th International Conference on Data Engineering (ICDE) Optimization of GPU-based Sparse Matrix Multiplication for Large Sparse Networks Jeongmyung Lee, Seokwon Kang, Yongseung Yu, Yong-Yeon Jo, Sang-Wook Kim, Yongjun Park Department of Computer Science Hanyang University, Seoul, Korea {jeongmyung, kswon0202, dydtmd1991, jyy0430, wook, yongjunpark}@hanyang.ac.kr Abstract—Sparse matrix multiplication (spGEMM) is widely computational throughput using single-instruction, multiple- used to analyze the sparse network data, and extract important thread (SIMT) programming models, such as CUDA [6] information based on matrix representation. As it contains a and OpenCL [7]. A GPU generally consists of a set of high degree of data parallelism, many efficient implementations using data-parallel programming platforms such as CUDA and Streaming Multiprocessors (SMs). OpenCL/CUDA programs OpenCL have been introduced on graphic processing units are executed on GPUs by allocating Thread Blocks (TBs) or (GPUs). Several well-known spGEMM techniques, such as cuS- Cooperative Thread Arrays (CTAs) 1, which are groups of PARSE and CUSP, often do not utilize the GPU resources fully, threads, to each SM in parallel. owing to the load imbalance between threads in the expansion The main challenge is developing an efficient matrix multi- process and high memory contention in the merge process. Furthermore, even though several outer-product-based spGEMM plication technique considering the data-specific characteristics techniques are proposed to solve the load balancing problem of sparsity and power-law degree distribution [8]. Typical on expansion, they still do not utilize the GPU resources fully, sparse networks contain a much smaller number of edges with because severe computation load variations exist among the non-zero values, compared to the number of all possible edges multiple thread blocks.
    [Show full text]
  • Introduction to Programming with Arrays Using ELI
    Introduction to Programming with Arrays using ELI by Wai-Mee Ching July, Nov., Dec. 2014 Copyright © 2014 Contents 1. Array, List and Primitive Operations in ELI ......................................................................................................... 3 1.1 Computers and Programming Languages ............................................................................................................ 3 1.2 ELI System and its Data Types ............................................................................................................................ 6 1.3 Shape of Data, Reshape and Data Conversion ................................................................................................... 10 1.4 Mathematical Computations .............................................................................................................................. 13 1.5 Comparisons, Selection, Membership and Index of .......................................................................................... 17 1.6 Array Indexing, Indexed Assignment and taking Sections ................................................................................ 21 1.7 Array Transformations ....................................................................................................................................... 26 1.8 Operators and Derived Functions ...................................................................................................................... 31 1.9 Lists and Operations on Lists............................................................................................................................
    [Show full text]
  • Sparse Matrix-Vector Multiplication on Gpgpus
    Sparse Matrix-Vector Multiplication on GPGPUs SALVATORE FILIPPONE VALERIA CARDELLINI Cranfield University DAVIDE BARBIERI ALESSANDRO FANFARILLO Universit`adegli Studi di Roma \Tor Vergata" Abstract The multiplication of a sparse matrix by a dense vector (SpMV) is a centerpiece of scientific computing applications: it is the essential kernel for the solution of sparse linear systems and sparse eigenvalue problems by iterative methods. The efficient implementation of the sparse matrix- vector multiplication is therefore crucial and has been the subject of an immense amount of research, with interest renewed with every major new trend in high performance computing architectures. The introduction of General Purpose Graphics Processing Units (GPGPUs) is no exception, and many articles have been devoted to this problem. With this paper we provide a review of the techniques for implementing the SpMV kernel on GPGPUs that have appeared in the literature of the last few years. We discuss the issues and tradeoffs that have been encountered by the various researchers, and a list of solutions, organized in categories according to common features. We also provide a performance comparison across different GPGPU models and on a set of test matrices coming from various application domains. Categories and subject descriptors:D.2.11[Software Engineering]: Soft- ware Architectures|Data abstraction; G.1.3[Numerical Analysis]: Nu- merical Linear Algebra|Sparse, structured, and very large systems (direct and iterative methods); G.4[Mathematical Software]: Algorithm
    [Show full text]