Enhancing the Malloc System with Pollution Awareness for Better Cache Performance
Abstract: Cache pollution, by which weak weak-locality locality data unduly replaces strong-locality strong data, may notably degrade application performance in a shared shared-cache cache multicore machine. This paper presents NightWatch, a cache management subsystem that provides general, transparent and low low-overhead overhead pollution control to applications. NightWatch is based on the observation that data within the same memory chunk or chunks within the same allocation context often share similar locality property. NightWatch embodies this observation by online monitoring current cache locality to predict future behavior and restricting potential cache polluters proactively. We have integrated NightWatch into two popular allocators, tcmalloc and ptmalloc2. Experiments with SPEC CPU2006 show that NightWatch improves application performance by up to 45 percent (18 percent on average), with an average monitoring overhead of 0.57 percent (up to 3.02 percent).