Kismet

Abstract

Software engineers now face the difficult task of refactoring serial programs for parallel execution on multicore processors. Currently, they are offered little guidance as to how much benefit may come from this task, or how close they are to the best possible parallelization. This paper presents Kismet, a tool that creates parallel speedup estimates for unparallelized serial programs. Kismet differs from previous approaches in that it does not require any manual analysis or modification of the program. This difference allows quick analysis of many programs, avoiding wasted engineering effort on those that are fundamentally limited. To accomplish this task, Kismet builds upon the hierarchical critical path analysis (HCPA) technique, a recently developed dynamic analysis that localizes parallelism to each of the potentially nested regions in the target program. It then uses a parallel execution time model to compute an approximate upper bound for performance, modeling constraints that stem from both hardware parameters and internal program structure.