June 16-20, 2013

Leipzig, Germany

Session Details

Name: Tutorial 09
Hybrid Parallel Programming with MPI & OpenMP
Time: Sunday, June 16, 2013
2:00 PM - 6:00 PM
Room:   Seminar Room 6/7 (SR 6/7)
CCL - Congress Center Leipzig
Breaks:4:00 PM - 4:30 PM Coffee Break
Presenter(s):   Georg Hager, Erlangen Regional Computing Center
  Gabriele Jost, Supersmith
  Rolf Rabenseifner, HLRS
Abstract:   Most HPC systems are clusters of shared memory nodes. Such systems can be PC clusters with single/multi-socket and multi-core SMP nodes, but also “constellation” type systems with large SMP nodes. Parallel programming may combine the distributed memory parallelization on the node interconnect with the shared memory parallelization inside of each node.
This tutorial analyzes the strengths and weaknesses of several parallel programming models on clusters of SMP nodes. Multi-socket-multi-core systems in highly parallel environments are given special consideration. MPI-3.0 introduced a new shared memory programming interface, which can be combined with MPI message passing and remote memory access on the cluster interconnect. It can be used for direct neighbor accesses similar to OpenMP or for direct halo copies, and enables new hybrid programming models. These models are compared with various hybrid MPI+OpenMP approaches and pure MPI. This tutorial also includes a discussion on planned future OpenMP support for accelerators. Benchmark results on different platforms are presented. Numerous case studies demonstrate the performance-related aspects of hybrid programming, and application categories that can take advantage of this model are identified. Tools for hybrid programming such as thread/process placement support and performance analysis are presented in a "how-to" section.

Content Level
25% Introductory, 50% Intermediate, 25% Advanced

Target Audience
People who are in charge with the development of efficient parallel software on clusters of shared memory nodes.

Some knowledge about parallel programming with MPI and OpenMP.
Program may be subject to changes.