Another combining scheme to reduce hot spot contention in large scale shared memory parallel computers

  • Gyungho Lee
Session 2: Parallel Architectures
Part of the Lecture Notes in Computer Science book series (LNCS, volume 297)


Concurrent requests to a shared variable by many processors on a shared memory machine can create contention that will be serious enough to stall large machines. This idea has been formalized in the “hot spot” traffic [PfNo85], where a fixed fraction of memory requests is for a single shared variable. “Combining”, in which several requests for the same variable can be combined into a single request, has been suggested as an effective method of alleviating the contention. Lee, Kruskal, and Kuck [LeKK86] introduced the idea of “k-way combining”, which shows that the effectiveness of combining depends on k, the maximum possible number of requests combined into a single request at a switch. This paper introduces a scheme to remedy k-way combining in order to avoid the contention without incurring impractically large storages in switches of multistage interconnection networks.


Shared Memory Memory Module Return Path Memory Request Multistage Interconnection Network 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [DiKS86]
    S. Dickey, R. Kenner, and M. Snir, “An Implementation of a Combining Network for the NYU Ultracomputer” Ultracomputer Note #93, NYU, Jan. 1986.Google Scholar
  2. [DKSS86]
    S. Dickey, R. Kenner, M. Snir, and J. Solworth, “A VLSI Combining Network for the NYU Ultracomputer” IEEE Proc. of the Intl. Conf. on Computer Design, pp. 110–113, Oct. 1986.Google Scholar
  3. [EGKM85]
    J. Edler, A. Gottlieb, C. P. Kruskal, K. P. McAuliffe, L. Rudolph, M. Snir, P. J. Teller, and J. Willson “Issues Related to MIMD Shared-Memory Computers: The NYU Ultracomputer Approach”, The 12th Annual International Symp. on Computer Architecture, June, 1985, pp.126–135Google Scholar
  4. [Feng81]
    T. Y. Feng, “A Survey of Interconnection Networks”, IEEE Computer, Vol.14 no.12 1981, pp. 12–27Google Scholar
  5. [GKLS83]
    D. D. Gajski, D. J. Kuck, D. Lawrie, and A. Sameh, “Cedar — A Large Scale Multiprocessors”, Proc. of the 1983 International Conf. on Parallel Processing, Aug. 1983, pp. 524–529Google Scholar
  6. [GoLi73]
    G. R. Goke and G. J. Lipovski, “Banyan Networks for Partitioning Multiprocessor Systems”, The 1st Annual Symposium on Computer Architecture, 1973, pp. 21–28Google Scholar
  7. [GGKM83]
    A. Gottlieb, R. Grishman, C. P. Kruskal, K. M. McAuliffe, L. Rudolph, and M. Snir, “The NYU Ultracomputer — designing an MIMD shared memory parallel computer”, IEEE Trans. on Computers, Vol. C-32, No. 2, 1983 Google Scholar
  8. [KrRS86]
    C. P. Kruskal, L. Rudolph, and M. Snir, “Efficient Synchronization on Multiprocessors with Shared Memory”, The 5th ACM SIGACT-SIGOPS Symp. on Principles of Distributed Computing, Aug. 1986Google Scholar
  9. [KrSn82]
    C. P. Kruskal and M. Snir, “Some Results on Multistage Interconnection Networks for Multiprocessors”, NYU Ultracomputer note 41; also in Proc. 1982 Conf. Informat. Sci. Syst., Princeton Univ., Princeton, NJ, Mar. 1982Google Scholar
  10. [KrSn83]
    C. P. Kruskal and M. Snir, “The Performance of Multistage Interconnection Networks for Multiprocessors”, IEEE Trans. on Computers, Vol. c-32, No. 12, Dec. 1983, pp.1091–1098Google Scholar
  11. [KrSW86]
    C. P. Kruskal, M. Snir, and A. Weiss, “The Distribution of Waiting Times in Clocked Multistage Interconnection Networks”, Proc. of the 1986 International Conf. on Parallel Processing, Aug. 1986, pp. 12–19Google Scholar
  12. [KDLS86]
    D. J. Kuck, E. S. Davidson, D. H. Lawrie, and A. H. Sameh, “Parallel Supercomputing Today and the Cedar Approach”, Science, Vol. 281, Feb. 28, 1986, pp. 967–974Google Scholar
  13. [Lawr75]
    D. H. Lawrie, “Access and Alignment of Data in an Array Processor”, IEEE Trans. on Computers, Vol. c-24, no.12 1975, pp.1145–1155Google Scholar
  14. [LeKK86]
    G. Lee, C. P. Kruskal, and D. J. Kuck, “The Effectiveness of Combining in Shared Memory Parallel Computers in the Presence of ‘Hot Spots'”, Proc. of the 1986 International Conf. on Parallel Processing, Aug. 1986, pp.35–41Google Scholar
  15. [LeeG87a]
    G. Lee, “A Performance Bound of Multistage Combining Networks”, submitted for publication in IEEE Trans. on Computers, 1987Google Scholar
  16. [LeeG87b]
    G. Lee, “A Balanced k-way Combining Switch”, in preparation, 1987Google Scholar
  17. [LeeR85]
    R. Lee, “On Hot Spot Contention”, ACM Computer Architecture News, Vol.13 no.5 1985, pp.15–20Google Scholar
  18. [Pate81]
    J. A. Patel, “Performance of Processor-Memory Interconnections for Multiprocessors”, IEEE Trans. on Computers, Vol. c-30, 1981, pp. 771–780Google Scholar
  19. [PBGH85]
    G. F. Pfister, W. C. Brantley, D. A. George, S. L. Harvey, W. J. Kleinfelder, K. P. McAuliffe, E. A. Melton, V. A. Norton, J. Weiss, “The IBM Research Parallel Processor Prototype (RP3): Introduction and Architecture”, Proc. of the 1985 International Conf. on Parallel Processing, Aug. 1985, pp.764–771Google Scholar
  20. [PfNo85]
    G. F. Pfister and V. A. Norton, “'Hot Spot’ Contention and Combining in Multistage Interconnection Networks”, IEEE Trans. on Computers, Vol. c-34, No.10, 1985, pp.943–948Google Scholar
  21. [Sieg85]
    Howard Jay Siegel, Interconnection Networks for Large-Scale Parallel Processing, Theory and Case Studies, Lexington Books. 1985Google Scholar
  22. [SuBK77]
    H. Sullivan, T. Bashkow, and D. Klappholtz, “A Large Scale Homogeneous Fully Distributed Parallel Machine”, Proc. of the Fourth Symp. on Computer Architecture, 1977, pp. 105–124Google Scholar
  23. [Wong86]
    M. C. Wong, “A Combining Omega Network: Performance vs Implementation” IBM Research Report, RC 11977 (#53952), June 1986.Google Scholar
  24. [YeTL86]
    P. C. Yew, N. F. Tzeng, and D. H. Lawrie, “Distributing Hot-Spot Addressing in Large Scale Multiprocessor”, Proc. of the 1986 International Conf. on Parallel Processing, Aug. 1986, pp.51–58Google Scholar
  25. [ZhYe84]
    C. Q. Zhu and P. C. Yew, “A Synchronization Scheme and Its Applications for Larger Multiprocessor Systems”, Proc. 4th International Conf. Distributed Computing Systems, May 1984, pp. 486–493Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1988

Authors and Affiliations

  • Gyungho Lee
    • 1
  1. 1.The Center for Advanced Computer StudiesUniversity of Southwestern LouisianaLafayette

Personalised recommendations