A Study of the Bucket-Exchange Pattern in the PGAS Model Using the ISx Integer Sort Mini-Application

ISx is an open-source integer sort mini-application that was released as a research vehicle for the study of irregular all-to-all communication patterns. The mini-app is uniquely valuable to the PGAS community because its dynamic, data dependent communication pattern presents an opportunity to show the benefit of the PGAS abstraction and one-sided communication. Its original release featured an implementation in OpenSHMEM as well as MPI two-sided for comparison. Our analysis showed the OpenSHMEM version spent up to 65% less time in the communication phase compared to the MPI two-sided implementation. From there, we began to explore porting ISx to other PGAS languages and created a Chapel implementation to compare performance and programmability trade-offs. This paper summarizes some of the results from the first year of research findings using ISx and discusses plans for future work.