¹University of Tübingen, Tübingen, Germany

Correspondence: Wolfgang Blochinger, University of Tübingen, WSI/SR, Sand 14, 72076 Tübingen, Germany. Tel: +49 7071 2970469; Fax: +49 7071 295160; blochinger@informatik.uni-tuebingen.de

Received 30 December 2005; Revised 14 March 2006; Accepted 17 March 2006; Published online 25 May 2006.

Abstract

This paper deals with a visualization-based approach to performance analyzing and tuning of highly irregular task-parallel applications. At its core lies a novel automatic layout algorithm for execution graphs which is based on Sugiyama's framework. Our visualization enables the application designer to reliably detect manifestations of parallel overhead and to investigate on their individual root causes. We particularly focus on structural properties of task-parallel computations which are hard to detect in a more analytical way, for example, false sharing and false parallelism. In addition, we discuss embedding our visualization into an integrated development environment, realizing a seamless work-flow for implementation, execution, analysis, and tuning of parallel programs.