FLRU:一种面向闪存固态盘的缓存管理算法  

FLRU: A Caching Algorithm for Flash-based SSDs

作　　者：沈岩[1] 骆力明[1] 罗圣美[2,3] 张广艳[2] 

机构地区：[1]首都师范大学信息工程学院,北京100048 [2]清华大学计算机科学与技术系,北京100084 [3]中兴通讯股份有限公司南京研究院,南京210012

出　　处：《小型微型计算机系统》2016年第6期1355-1359,共5页Journal of Chinese Computer Systems

基　　金：国家"八六三"高技术研究发展计划项目(2013AA01A210)资助;国家自然科学基金项目(61371194;61170008;61272055)资助;北京市自然科学基金项目(4152012)资助

摘　　要：本文针对固态盘的写代价高于读代价的特性,提出了一种面向闪存固态盘的缓存管理算法FLRU.其核心思想是为每一类数据页维护一个双缓冲区LRU队列:冷数据LRU队列,热数据LRU队列.提出的算法优先置换冷的干净数据页和冷的脏页(从冷数据LRU队列中置换),其次从热数据LRU队列中置换干净数据页,最后置换热的脏数据页LRU中的数据页.实验表明,与其它算法相比,FLRU算法能够适应不同类型的读写负载,同时明显降低了读写代价.Existing algorithms adopted by operating systems consider the underlying devices as mechanical disks and ignore the asymmetry of read and write operations. And most existing flash-aware caching algorithms ignore the frequency of pages. In this paper,we propose a new caching algorithm for SSDs, called FLRU. It classifies pages into different types according to frequency and modification of pages. Each page type is organized by LRU. When selecting a victim page, FLRU replaces cold clean pages and cold dirty pages first and keeps balance between frequent pages and infrequent pages dynamically. We evaluate the performance of FLRU via tracedriven simulations. Experimental results show that FLRU can work well under different workloads, and reduce total read and write costs while avoiding significant degradation of hit ratio.

关 键 词：缓存 固态盘 读写代价 置换策略 

分 类 号：TP316[自动化与计算机技术—计算机软件与理论]