Abstract
In this paper we design and analyse parallel algorithms with the goal to get exact bounds on their speed-ups on real machines. For this purpose we define an extension of Valiant's BSP model, BSP*, that rewards blockwise communication, and uses Valiant's notion of c-optimality. Intuitively a c-optimal parallel algorithm for p processors achieves speed-up close to p/c. We consider the Multisearch problem: Assume a strip in 2D to be partitioned into m segments. Given n query points in the strip, the task is to locate, for each query, its segment. For m ≤ n we present a deterministic BSP* algorithm that is 1-optimal, if n = Ω(p log2 p). For m > n, we present a randomized BSP* algorithm that is (1 + δ)-optimal for arbitrary δ>0, m ≤ 2p and n=Ω(p log2 p). Both results hold for a wide range of BSP* parameters where the range becomes larger with growing input sizes m and n. We further report on implementation work in progress. Previous parallel algorithms for Multisearch were far away from being c-optimal in our model and do not consider blockwise communication.
Supported in part by DFG-Sonderforschungsbereich 1511 “Massive Parallelität: Algorithmen, Entwurfsmethoden, Anwendungen”, by DFG Leibniz Grant Me872/6-1, and by the Esprit Basic Research Action Nr 7141 (ALCOM II)
Preview
Unable to display preview. Download preview PDF.
References
A. Aggarwal, A.K. Chandra and M. Snir, On communication latency in PRAM computations, Proc. ACM Symp. on Parallel Algorithms and Architectures, 1989, 11–21.
M.J. Atallah, F. Dehne, R. Miller, A. Rau-Chaplin and J.-J. Tsay, Multisearch Techniques for Implementing Data Structures on a Mesh-Connected Computer, Proc. ACM Symp. on Parallel Algorithms and Architectures, 1991, 204–214.
M.J. Atallah and A. Fabri, On the Multisearching Problem for Hypercubes, Parallel Architectures and Languages Europe, 1994.
A. Bäumker, W. Dittrich, F. Meyer auf der Heide, Truly efficient parallel algorithms: c-optimal multisearch for an extension of the BSP model, Technical Report, Universität-Gesamthochschule Paderborn, Department of Mathematics and Computer Science, to appear.
R. H. Bisseling, W. F. McColl, Scientific computing on bulk synchronous parallel architectures, Proc. 13th IFIP World Computer Congress, Volume 1, 1994.
D. Culler, R. Karp, D. Patterson, A. Sahay, K.E. Schauser, E. Santos, R. Subramonian and T. von Eicken, LogP: Towards a Realistic Model of Parallel Computation, Proc. ACM SIGPLAN Symposium on Principles and Practice of Parallel Programming, 1993.
F. Dehne, A. Fabri, A. Rau-Chaplin, Scalable Parallel Computational Geometry for Coarse Grained Multicomputers, Proc. ACM Conf. on Comp. Geometry, 1993.
A.V. Gerbessiotis and L. Valiant, Direct Bulk-Synchronous Parallel Algorithms, Journal of Parallel and Distributed Computing, 1994.
W. Hoeffding, Probability inequalities for sums of bounded random variables, American Statistical Association Journal, 1963, 13–30.
C.P. Kruskal, L. Rudolph and M. Snir, A complexity theory of efficient parallel algorithms, Proc. 15th Int. Coll. on Automata, Languages, and Programming, 1988, 333–346.
W F McColl, The BSP Approach to Architecture Independent Parallel Programming, To appear in CACM on General Purpose Practical Models of Parallel Computation, 1995.
Abhiram Ranade, Maintaining dynamic ordered sets on processor networks, Proc. of the 4th ACM Symp. on Parallel Algorithms and Architectures, 1992, 127–137.
J.H. Reif and S. Sen, Randomized Algorithms for Binary Search and Load Balancing on Fixed Connection Networks with Geometric Applications, SIAM J. Comput., Vol. 23, No. 3, June 1994, 633–651.
L. Valiant, A Bridging Model for parallel Computation, Communications of the ACM, August 1994, Vol. 33, No. 8.
Author information
Authors and Affiliations
Editor information
Rights and permissions
Copyright information
© 1995 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Bäumker, A., Dittrich, W., Meyer auf der Heide, F. (1995). Truly efficient parallel algorithms: c-optimal multisearch for an extension of the BSP model. In: Spirakis, P. (eds) Algorithms — ESA '95. ESA 1995. Lecture Notes in Computer Science, vol 979. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-60313-1_131
Download citation
DOI: https://doi.org/10.1007/3-540-60313-1_131
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-60313-9
Online ISBN: 978-3-540-44913-3
eBook Packages: Springer Book Archive