Understanding the formation of wait states in applications with one-sided communication

To better understand the formation of wait states in MPI programs and to support the user in finding optimization targets in the case of load imbalance, a major source of wait states, we added in our earlier work two new trace-analysis techniques to Scalasca, a performance analysis tool designed for large-scale applications. In this paper, we show how the two techniques, which were originally restricted to two-sided and collective MPI communication, are extended to cover also one-sided communication. We demonstrate our experiences with benchmark programs and a mini-application representing the core of the POP ocean model