An architectural technique for cache-level garbage collection

Abstract

Cache performance is critical in high-speed computing systems. However, heapintensive programs such as LISP codes typically have low cache performance because of inherently poor data locality. To improve the cache performance, the system should reuse heap cells while they are in cache, thus reducing the number of cache misses due to heap references. Furthermore, the system can adopt multi-threaded architecture to hide the cache miss overhead by switching to different control threads when a cache miss occurs. In this paper, a novel architectural scheme called cache-level garbage collection based on multi-threading is developed to improve the cache performance for heap-intensive programs. Consequently both the cache hit ratio is improved and the cache miss overhead is masked, thereby minimizing the total cache miss penalty. We present the garbage collection algorithm and its architectural support features, together with initial performance evaluation.