Transformations to Parallel Codes for Communication-Computation Overlap Session: Performance Optimization Event Type: Paper Time: 4:00pm - 4:30pm Session Chair: Beth Simon Speaker(s): Anthony Danalis, Ki-Yong Kim, Lori Pollock, Martin Swany Location: 606-607 Abstract: This paper presents program transformations directed toward improving communication-computation overlap in parallel programs that use MPI's collective operations. Our transformations target a wide variety of applications focusing on scientific codes with computation loops that exhibit limited dependence among iterations. We include guidance for developers for transforming an application code in order to exploit the communication-computation overlap available in the underlying cluster, as well as a discussion of the performance improvements achieved by our transformations. We present results from a detailed study of the effect of the problem and message size, level of communication-computation overlap, and amount of communication aggregation on runtime performance in a cluster environment based on an RDMA-enabled network. The targets of our study are two scientific codes written by domain scientists, but the applicability of our work extends far beyond the scope of these two applications. This paper can be found in the ACM and IEEE Digital Libaries Click here for ACM Click here for IEEE Chair/Speaker Details: Beth Simon (Chair) SDSC Anthony Danalis University of Delaware Ki-Yong Kim University of Delaware Lori Pollock University of Delaware Martin Swany University of Delaware