混合映射方式下NAND闪存垃圾回收算法  

NAND Flash Garbage Collection Algorithm in Hybrid Mapping Mode

作　　者：张靖君 王玲 ZHANG Jing-jun;WANG Ling(College of Information Science and Engineering,Hunan Normal University,Changsha 410006,China)

机构地区：[1]湖南师范大学信息科学与工程学院

出　　处：《小型微型计算机系统》2019年第10期2139-2142,共4页Journal of Chinese Computer Systems

摘　　要：针对基于混合映射的FAST算法中垃圾回收开销大、磨损均衡效果差和I/O响应时间长的问题,提出一种基于混合映射的垃圾回收算法.该算法提出了一种基于循环队列的冷热块识别方法,识别方法通过对队列中相同逻辑块地址的热度权值进行求和得到逻辑块的热度值,并将写入的数据按照所在逻辑块的热度值分为"热"数据和"冷"数据,分别写入到不同擦除次数的日志块中,减少全合并的次数.同时,算法还构造了一种新的回收代价函数用于选择回收块,在考虑回收开销的同时,还兼顾磨损均衡的问题.实验结果表明,该算法与FAST算法相比,磨损均衡效果有较大提升,总擦除次数和全合并次数大幅减少,I/O响应时间明显降低.Aiming at the problem of large garbage collection overhead,poor wear leveling effect and long I/O response time in FAST algorithm based on hybrid mapping,a garbage collection algorithm based on hybrid mapping is proposed. The algorithm proposes a cold-hot block identification method based on circular queue. The identification method obtains the heat value of the logical block by summing the heat weights of the same logical block address in the queue,and the written data is according to the logical block. The heat value is divided into "hot"data and"cold"data,which are respectively written into log blocks of different erasure times,reducing the number of full merges. At the same time,the algorithm also constructs a newrecovery cost function for selecting the recovery block. Considering the recovery overhead,it also considers the problem of wear leveling. The experimental results show that compared with the FAST algorithm,the wear leveling effect is greatly improved,the total number of erasures and the total number of merges are greatly reduced,and the I/O response time is significantly reduced.

关 键 词：FAST算法 磨损均衡 垃圾回收 逻辑块 

分 类 号：TP316[自动化与计算机技术—计算机软件与理论]