A Performance Study of Software Prefetching for Tracing Garbage Collectors

摘要

In automatic memory management programming language, the garbage collector is an important feature which reclaims memory that is no longer referenced by the program. The tracing collector performs a transitive closure across the object reference graph. And this process may result in too many cache misses, because the traverse exhibits poor locality. Previous studies have already proposed using software prefetching to improve memory performance of garbage collector. In this work, we studied the characteristic of prefetch instructions on x86 platforms in detail, and proposed a method to control the pre-fetch ratios by address thresholds. The experimental results show that a further improvement and optimization is obtained by tuning the prefetch ratio. We use these results to devise some guidelines for optimizing the memory performance as well as minimizing the collection pause times.