A Multiple LRU List Buffer Management Algorithm

Abstract

Paper[1] proposes LLRU algorithm. The buffer is divided into four categories in LLRU: cold clean LRU list, cold dirty LRU list, hot clean LRU list and hot dirty LRU list. But the cold clean LRU list may be empty when the algorithm runs for a while. Then a new page just reading in buffer will be victim when the LLRU selects the victim page, leading to a clean page hard to turn into a hot page. The AM-LRU proposed in this paper ensures that the cold clean page has the chance to turn into a hot page by setting the minimum length of the cold clean LRU list and adopting secondary opportunity replacement strategy for the victim page from the hot area. As a result, compared with LLRU, the hit rate of AM-LRU can be improved and the flash reads counts, writes counts and erases counts can be reduced.