Visualizing performance debugging

The authors examine a special software development environment called the Parallel Programming and Instrumentation Environment (PIE). PIE is designed to develop performance-efficient parallel and sequential computations. Following an explanation of PIE´s general theory and features, PIE´s visualization tools are used to isolate and repair the parallelism problem of an eight-process computation. Two more difficult examples using PIE are discussed. Some of the issues involved in correctly presenting visual information, such as the features users ask for and what can be done about a performance monitor´s perturbation of computations, are addressed.<>