Hybrid programming model for implicit PDE simulations on multicore architectures

  • Authors:
  • Dinesh Kaushik;David Keyes;Satish Balay;Barry Smith

  • Affiliations:
  • King Abdullah University of Science and Technology, Saudi Arabia;King Abdullah University of Science and Technology, Saudi Arabia;Argonne National Laboratory, Argonne, IL;Argonne National Laboratory, Argonne, IL

  • Venue:
  • IWOMP'11 Proceedings of the 7th international conference on OpenMP in the Petascale era
  • Year:
  • 2011

Quantified Score

Hi-index 0.00

Visualization

Abstract

The complexity of programming modern multicore processor based clusters is rapidly rising, with GPUs adding further demand for fine-grained parallelism. This paper analyzes the performance of the hybrid (MPI+OpenMP) programming model in the context of an implicit unstructured mesh CFD code. At the implementation level, the effects of cache locality, update management, work division, and synchronization frequency are studied. The hybrid model presents interesting algorithmic opportunities as well: the convergence of linear system solver is quicker than the pure MPI case since the parallel preconditioner stays stronger when hybrid model is used. This implies significant savings in the cost of communication and synchronization (explicit and implicit). Even though OpenMP based parallelism is easier to implement (with in a subdomain assigned to one MPI process for simplicity), getting good performance needs attention to data partitioning issues similar to those in the message-passing case.