Engineering Efficient Paging Algorithms

In the field of online algorithms, paging is a well-studied problem. LRU is a simple paging algorithm that incurs few cache misses and supports efficient implementations. Algorithms outperforming LRU in terms of cache misses exist but are in general more complex and thus not automatically better, since their increased runtime might annihilate the gains in cache misses. In this article, we focus on efficient implementations for the OnOPT class described in Moruz and Negoescu [2012], particularly on an algorithm in this class, denoted RDM, that was shown to typically incur fewer misses than LRU. We provide experimental evidence on a wide range of cache traces showing that our implementation of RDM is competitive to LRU with respect to runtime. In a scenario incurring realistic time penalties for cache misses, we show that our implementation consistently outperforms LRU, even if the runtime of LRU is set to zero.