Improving cache performance by selective cache bypass

Abstract

A technique is proposed to prevent the return of infrequently used items to cache after they are bumped from it. Simulations have shown that the return of these items, called cache pollution, typically degrade cache-based system performance (average reference time) by 10% to 30%. The technique proposed involves the use of hardware called a bypass-cache, which, under program control, will determine whether each reference should be through the cache or should bypass the cache and reference main memory directly. Several inexpensive heuristics for the compiler to determine how to make each reference are given. It is shown that much of the performance loss can be regained.<>