Multi-bank闪存文件系统的一种I/O调度机制  

Efficient I/O Scheduler over Multi-bank Flash Memory File Systems

作　　者：赵培[1] 李国徽[1] 

机构地区：[1]华中科技大学计算机学院,武汉430074

出　　处：《计算机科学》2012年第4期287-292,共6页Computer Science

基　　金：国家自然科学基金(60873030);国家高技术研究发展计划(863)(2007AA01Z309);国家"十一五"国防预研基金资助

摘　　要：闪存以其体积小、抗震性强、能耗低、读取速度快等特点,被广泛应用于存储系统中。NOOP是闪存上传统的调度方法,但是NOOP的I/O性能较低,不能满足很多应用程序的要求。根据闪存读取速度快、多个banks(chips)可以并行运行等特点,提出了一种基于闪存文件系统YAFFS的Multi-bank闪存调度方法(简称MBS)。MBS并行地执行请求,且给予读请求更高的优先级。MBS根据AVL-based-tree机制识别出的写请求属性动态地将其分配到合适的bank中。实验结果表明,相比NOOP,MBS调度具有更高的I/O吞吐率、更短的请求响应时间并具有均匀的bank擦除次数和利用率。Flash memory has been widely used in storage systems because of its nonvolatile nature,its small size,shock resistance and fast access speed.The traditional scheduler over flash memory storage systems is NOOP scheduler.There is much room for improving the I/O performance,especially over multi-bank flash memory storage systems.Because several banks can operate simultaneously,we proposed a new scheduler called Multi-Bank flash memory Scheduler（MBS） based on the native file system YAFFS to take advantage of the parallelism of multiple banks by considering the high read speed.A flexible bank assignment policy was proposed to assign proper banks for write requests according to the attributes（hot or cold） of requests,which were identified by an AVL-based-tree mechanism.MBS scheduler reorders read and write requests and gives higher priority to reads.The experimental results show that the I/O throughputs and average response time are improved significantly compared with the NOOP scheduler.An even erasable count and capacity utilization were obtained between different banks in the multi-bank storage system.

关 键 词：Multi-bank闪存 I/O调度 native闪存文件系统 bank动态分配策略 请求属性的识别 

分 类 号：TP316[自动化与计算机技术—计算机软件与理论]