论文标题
舞台查找：使用目录快捷方式加速路径查找
Stage Lookup: Accelerating Path Lookup using Directory Shortcuts
论文作者
论文摘要
当虚拟文件系统（VFS）一个接一个地遍历文件路径组件时，Linux中的查找过程花费了很大一部分文件访问时间。当应用程序经常访问文件，尤其是那些尺寸较小的文件时，查找过程变得更加耗时。我们提出了舞台查找，该舞台查找动态缓解了流行的目录，以加快查找过程并进一步减少文件访问延迟。舞台查找的核心是将流行的齿条作为快捷方式缓存，因此路径行走不会烦恼从根部遍历目录树。此外，舞台查找丰富的向后路径在将VFS中的目录树视为无向地图时，它会走路。我们实现了舞台查找原型，并将其集成到Linux内核v3.14中。我们广泛的绩效评估研究表明，与普通路径查找方案相比，舞台查找可提供多达46.9％的性能增长。此外，与原始方法相比，舞台查找显示了重命名和CHMOD操作的较小性能开销。
The lookup procedure in Linux costs a significant portion of file accessing time as the virtual file system (VFS) traverses the file path components one after another. The lookup procedure becomes more time consuming when applications frequently access files, especially those with small sizes. We propose Stage Lookup, which dynamically caches popular directories to speed up lookup procedures and further reduce file accessing latency. The core of Stage Lookup is to cache popular dentries as shortcuts, so that path walks do not bother to traverse directory trees from the root. Furthermore, Stage Lookup enriches backward path walks as it treats the directory tree in a VFS as an undirected map. We implement a Stage Lookup prototype and integrate it into Linux Kernel v3.14. Our extensive performance evaluation studies show that Stage Lookup offers up to 46.9% performance gain compared to ordinary path lookup schemes. Furthermore, Stage Lookup shows smaller performance overheads in rename and chmod operations compared to the original method of the kernel.
