Sunday, Half Day, AM
Room A112

Title: Mixed-Mode Programming Introduction

Presenters: Daniel Duffy and Mark R. Fahey, Computer Sciences Corporation - Engineer Research and Development Center Major Shared Resource Center

Level: 40% Introductory | 40% Intermediate | 20% Advanced

Abstract:

This tutorial will discuss the benefits and pitfalls of multilevel parallelism (MP) using the Message Passing Interface (MPI) combined with threads. Examples from the author's experiences will be discussed to give motivation to why multilevel parallelism is beneficial. While a general knowledge of MPI is assumed, the presentation will introduce both OpenMP directives and Pthreads. Furthermore, starting from the context of multithreading an existing MPI application, a general method of how to include threads will be discussed.

Included will be discussions of the pros and cons of various tools that can be used across platforms to help the application developer to optimize and debug an MP program. Also, sample codes showing a comparison of different MP methods will be shown and their resulting speedups presented. Finally, lessons learned from unsuccessful experiences of the authors will be presented.