嵌入式NHD系统I/O性能分析及优化  

Analysis and Optimization of I/O Performance for Embedded NHD System

作　　者：刘海洋[1] 孟晓烜[1] 库依楠[1] 许鲁[1] 

机构地区：[1]中国科学院计算技术研究所

出　　处：《小型微型计算机系统》2007年第7期1334-1338,共5页Journal of Chinese Computer Systems

基　　金：国家自然科学基金项目(60373045)资助.

摘　　要：嵌入式NHD(Network Hard Disk)系统是一种动态连接计算资源和存储资源的装置,它以硬件的方式对ATA存储控制器的访问接口进行功能模拟,即将对标准磁盘访问的ATA协议转化为对网络存储设备访问的NBD协议,从而为计算子系统提供虚拟的存储空间.文章对NHD系统的I/O性能进行分析,并针对性采用了DMA流水、零拷贝和TCP校验和卸载等优化技术.实验数据表明,在不改变硬件配置条件下,优化后NHD系统的I/O性能由原来的1.05MB/s提升为3.45MB/s,基本达到实用化需求.The embedded NHD （Network Hard Disk） system is a specialized device which is able to connect computing resource and storing resource. As a hardware device, it simulates the functions of data-accessing interface based on ATA protocol by translating the standard ATA into its counterpart of NBD, a network block transport protocol. In this way, it provides a virtu- al storage space for local computing subsystem. This paper analyzes the I/O performance of NHD system and carries out some corresponding optimization technologies, such as DMA streaming, zero-copy, TCP-checksum offloading etc. The experiment results show that the I/O performance of optimized NHD system with the same hardware configuration as the original one is improved from 1.05MBps to 3.45MBps.

关 键 词：NHD I/O性能 DMA流水 零拷贝 

分 类 号：TP333[自动化与计算机技术—计算机系统结构]