Understanding the Limits of Capacity Sharing in CMP Private Caches
Chip Multi Processor (CMP) systems present interesting design challenges at the lower levels of the cache hierarchy. Private L2 caches allow easier processor-cache design reuse, thus scaling better than a system with a shared L2 cache, while offering better performance isolation and lower access latency. While some private cache management schemes that utilize space in peer private L2 caches have been recently proposed, the authors find that there is significant potential for improving their performance. They propose and study an oracular scheme, OPT, which identifies the performance limits of schemes to manage private caches. OPT uses offline-generated traces of cache accesses to uncover applications' reuse patterns.