1Integrated Performance Views in Charm++: Projections Meets TAU

Abstract—The Charm++ parallel programming system pro-vides a modular performance interface that can be used to extend its performance measurement and analysis capabilities. The inter-face exposes execution events of interest representing Charm++ scheduling operations, application methods/routines, and com-munication events for observation by alternative performance modules configured to implement different measurement features. The paper describes the Charm++’s performance interface and how the Charm++ Projections tool and the TAU Performance System can provide integrated trace-based and profile-based per-formance views. These two tools are complementary, providing the user with different performance perspectives on Charm++ applications based on performance data detail and temporal and spatial analysis. How the tools work in practice is demonstrated in a parallel performance analysis of NAMD, a scalable molecular dynamics code that applies many of Charm++’s unique features. Keywords-Charm++; TAU; Projections; NAMD; I