Model-Based relative performance diagnosis of wavefront parallel computations

Parallel performance diagnosis can be improved with the use of performance knowledge about parallel computation models. The Hercule diagnosis system applies model-based methods to automate performance diagnosis processes and explain performance problems from high-level computation semantics. However, Hercule is limited by a single experiment view. Here we introduce the concept of relative performance diagnosis and show how it can be integrated in a model-based diagnosis framework. The paper demonstrates the effectiveness of Hercule's approach to relative diagnosis of the well-known Sweep3D application based on a Wavefront model. Relative diagnoses of Sweep3D performance anomalies in strong and weak scaling cases are given.