Multitasking: experience with applications on a CRAY X-MP

Abstract On the multiprocessor vector-supercomputer CRAY X-MP, parallelism—beyond vectorization—can be exploited on the programming language level by two multitasking strategies: macrotasking and, more recently, microtasking. In this paper, multitasking results and experiences are presented which have been gained by applying these two implemented modes to linear-algebra and non-numerical algorithms as well as to a large fluid-flow simulation code. While comparing the concepts and realizations of macrotasking and microtasking, the features, tools, and problems of multitasking programming and the potential user benefit of these parallel processing techniques are discussed.

[1]  Harvey M. Deitel,et al.  An introduction to operating systems , 1984 .

[2]  Jack Dongarra,et al.  Implementing dense linear algebra algorithms using multitasking on the CRAY X-MP-4 (or approaching the Gigaflop) , 1986 .

[3]  Kai Hwang,et al.  Computer architecture and parallel processing , 1984, McGraw-Hill Series in computer organization and architecture.

[4]  Paolo Carnevali,et al.  Microtasking on IBM Multiprocessors , 1986, IBM J. Res. Dev..

[5]  Wolfgang E. Nagel,et al.  Three-dimensional numerical simulations of the czochralski bulk flow on a CRAY X-MP multiprocessor architecture , 1988, ICS '88.

[6]  Roger W. Hockney.  MIMD computing in the USA - 1984 , 1985, Parallel Comput..

[7]  W. E Nagel.  1988 International conference on supercomputing , 1988 .

[8]  Jack J. Dongarra,et al.  Squeezing the most out of an algorithm in CRAY FORTRAN , 1984, ACM Trans. Math. Softw..

[9]  Donald A. Calahan,et al.  Task granularity studies on a many-processor CRAY X-MP , 1985, Parallel Comput..

[10]  Jack J. Dongarra,et al.  Unrolling loops in fortran , 1979, Softw. Pract. Exp..

[11]  J. M. Ortega,et al.  The ijk forms of factorization methods I. Vector computers , 1988, Parallel Comput..

[12]  S. P. Kumar,et al.  Solving Linear Algebraic Equations on an MIMD Computer , 1983, JACM.

[13]  Joseph W. H. Liu,et al.  Computational models and task scheduling for parallel sparse Cholesky factorization , 1986, Parallel Comput..

[14]  Jürgen-Friedrich Hake,et al.  Linear algebra software on a vector computer , 1989, Parallel Comput..

[15]  Alfred V. Aho,et al.  Data Structures and Algorithms , 1983 .

[16]  M. Vitaletti,et al.  Microtasking on IBM multiprocessors and its implications on automatic parallelization , 1986 .

[17]  Renate GURKE,et al.  The approximate solution of the Euclidean traveling salesman problem on a CRAY X-MP , 1988, Parallel Comput..

[18]  Douglas J. Theis.  Vector supercomputers , 1974, Computer.

[19]  Wolfgang E. Nagel.  Using multiple CPUs for problem solving: experiences in multitasking on the CRAY X-MP/48 , 1988, Parallel Comput..

[20]  J. Ortega.  Introduction to Parallel and Vector Solution of Linear Systems , 1988, Frontiers of Computer Science.

[21]  Jack J. Dongarra,et al.  Multiprocessing linear algebra algorithms on the CRAY X-MP-2: Experiences with small granularity , 1984, J. Parallel Distributed Comput..

[22]  M. Mihelčić,et al.  Three-dimensional simulations of the Czochralski bulk flow , 1984 .

[23]  M. Mihelčić,et al.  Numerical simulations of the Czochralski bulk flow in an axial magnetic field: Effects on the flow and temperature oscillations in the melt , 1985 .