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A Proposal for Task-Generating Loops in OpenMP*

  • Xavier Teruel
  • Michael Klemm
  • Kelvin Li
  • Xavier Martorell
  • Stephen L. Olivier
  • Christian Terboven
Part of the Lecture Notes in Computer Science book series (LNCS, volume 8122)

Abstract

With the addition of the OpenMP* tasking model, programmers are able to improve and extend the parallelization opportunities of their codes. Programmers can also distribute the creation of tasks using a worksharing construct, which allows the generation of work to be parallelized. However, while it is possible to create tasks inside worksharing constructs, it is not possible to distribute work when not all threads reach the same worksharing construct. We propose a new worksharing-like construct that removes this restriction: the taskloop construct. With this new construct, we can distribute work when executing in the context of an explicit task, a single, or a master construct, enabling us to explore new parallelization opportunities in our applications. Although we focus our current work on evaluating expressiveness rather than performance evaluation, we present some initial performance results using a naive implementation for the new taskloop construct based on a lazy task instantiation mechanism.

Keywords

OpenMP Task Worksharing Loop Fork/Join 

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Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Xavier Teruel
    • 1
  • Michael Klemm
    • 2
  • Kelvin Li
    • 3
  • Xavier Martorell
    • 1
  • Stephen L. Olivier
    • 4
  • Christian Terboven
    • 5
  1. 1.Barcelona Supercomputing CenterSpain
  2. 2.Intel CorporationUSA
  3. 3.IBM CorporationUSA
  4. 4.Sandia National LaboratoriesUSA
  5. 5.RWTH Aachen UniversityGermany

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