Software prefetching for mark-sweep garbage collection: hardware analysis and software redesign

Tracing garbage collectors traverse references from live program variables, transitively tracing out the closure of live objects. Memory accesses incurred during tracing are essentially random: a given object may contain references to any other object. Since application heaps are typically much larger than hardware caches, tracing results in many cache misses. Technology trends will make cache misses more important, so tracing is a prime target for prefetching. Simulation of Java benchmarks running with the Boehm-Demers-Weiser mark-sweep garbage collector for a projected hardware platform reveal high tracing overhead (up to 65% of elapsed time), and that cache misses are a problem. Applying Boehm’s default prefetching strategy yields improvements in execution time (16% on average with incremental/generational collection for GCintensive benchmarks), but analysis shows that his strategy suffers from significant timing problems: prefetches that occur too early or too late relative to ...

• Type: Conference
• Year: 2004
• Where: ASPLOS
• Authors: Chen-Yong Cher, Antony L. Hosking, T. N. Vijaykumar
• Keywords: ASPLOS 2004, Cache Misses, Default Prefetching Strategy, GCintensive Benchmarks, Programming Languages