Linking Compilation and Visualization for Massively Parallel Programs

This paper presents a technique to visualize the communication pattern of a parallel application at different points during its execution. Unlike existing tools that show the communication pattern for the entire application, our tool breaks this communication pattern down into components to allow the more detailed study of application execution. These patterns are not merely snapshots or windows of the execution but rather are tied to specific code structures comprised of loops in the application. Our technique leverages our compiler, which adds instructions into the code to record where communications and code artifacts occur during execution. This information is stored into a trace format, which is read by our visualization tool. The visualization tool can graphically represent the communication pattern and message volume to allow a user to analyze and optimize the execution. As an example, we show how this information can be used to optimize the execution time and reduce the message delay of applications executed on a system enhanced with optical circuit switch interconnections.