LAPPS: Locality-Aware Productive Prefetching Support for PGAS.

Prefetching is a well-known technique to mitigate scalability challenges in the Partitioned Global Address Space (PGAS) model. It has been studied as either an automated compiler optimization or a manual programmer optimization. Using the PGAS locality awareness, we define a hybrid tradeoff. Specifically, we introduce locality-aware productive prefetching support for PGAS. Our novel, user-driven approach strikes a balance between the ease-of-use of compiler-based automated prefetching and the high performance of the laborious manual prefetching. Our prototype implementation in Chapel shows that significant scalability and performance improvements can be achieved with minimal effort in common applications.