Compiling for software distributed-shared memory systems

Abstract

In this thesis, we explore the use of software distributed shared memory (SDSM) as a target communication layer for parallelizing compilers. We explore how to effectively exploit compiler-derived knowledge of sharing and communication patterns for regular access patterns to improve their performance on SDSM systems. We introduce two novel optimization techniques: compiler-restricted consistency which reduces the cost of false sharing, and compiler-managed communication buffers which, when used together with compiler-restricted consistency, reduce the cost of fragmentation. We focus on regular applications with wavefront computation and tightly-coupled sharing due to carried data dependence. Along with other types of compiler-assisted SDSM optimizations such as compiler-controlled eager update, our integrated compiler and run-time support provides speedups for wavefront computations on SDSM that rival those achieved previously only for loosely synchronous style applications. (Abstract shortened by UMI.