Cache performance improvement through on-demand, in-cache page clearing

Recent advances in VLSI technology have made it possible to use large enough caches to eliminate most of the ''conventional'' cache misses resulting from limited cache size and/or set associativity. As a result, other sources of ''non-conventional'' cache misses are becoming increasingly dominant in the makeup of the total cache misses. One of those sources is the clearing of remapped physical pages by the operating system, which is required for security reasons. Our experiment shows that the traditional method of ''over-eager'' clearing of remapped physical pages results in up to 13% of the total data cache misses. In this paper, we propose a novel method of page clearing to reduce such high cache overhead. Our scheme is based on ''on-demand'', ''in-cache'' page clearing and can be implemented efficiently on existing hardware. Our trace-driven simulation based on multitasking traces indicates that the proposed scheme can reduce up to 7% of the total data cache misses and up to 16% of the total stalls related to data access.