Pmfs中目录项索引的实现

发布时间：2018-07-01 19:33

  本文选题：持久化内存 + 目录项索引　； 参考：《计算机应用》2017年05期

【摘要】：可字节寻址的非易失存储介质,如相变存储器等,使数据可以在内存级别持久化。由于非易失存储器(NVM)本身的读写延时非常低,系统软件开销成为了决定整个持久化内存系统性能的主要因素。Pmfs是一个专门为持久化内存所设计的文件系统,然而,Pmfs下的每个目录操作(打开、创建或删除)都会遍历目录下的所有目录项,导致了随文件数增长而线性增长的目录项查找开销。通过测试发现,在特定类型负载下这种开销成为了整个文件系统的瓶颈。针对该问题,在Pmfs中实现了持久化的目录项索引来加速目录操作。测试结果显示,基于单目录下100 000文件的负载,该优化使得文件创建速度提高了12倍,带宽增加了27.3%。
[Abstract]:Byte-addressable nonvolatile storage media, such as phase change memory, enables data to persist at the memory level. Since the non-volatile memory (NVM) itself has very low read and write latency, the system software overhead has become the main factor that determines the performance of the entire persistent memory system. Pmfs is a file system specially designed for persistent memory. However, every directory operation (open, created, or deleted) under Pmfs will traverse all the directory entries in the directory, resulting in a linearly increasing directory item lookup overhead with the increase of the number of files. It is found that this overhead becomes the bottleneck of the whole file system under certain load types. To solve this problem, persistent index of directory items is implemented in Pmfs to accelerate directory operation. The test results show that, based on the load of 100,000 files in a single directory, this optimization increases the speed of file creation by 12 times and the bandwidth by 27.3.
【作者单位】： 国防科学技术大学计算机学院;
【基金】：国家863计划项目(2015AA015305)~~
【分类号】：TP333
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本文编号：2088920