Linux Directory Cache (dcache) Optimization

For more details about the principles and designs of this optimization, please see this paper:

How to Get More Value From Your File System Directory Cache
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Chia-Che Tsai, Yang Zhan, Jayashree Reddy, Yizheng Jiao, Tao Zhang, Donald E. Porter (Stony Brook University)
Published in SOSP 2015

This code is a optimized design of Linux directory cache, to improve hit latency for path lookup, and reduce cache miss for directory listing and unique file creation.

Building instructions

This optimization is implemented on top of Linux 3.14 kernel, with changes in the dcache source code, including:

• include/linux/types.h
• include/linux/dcache.h
• include/linux/namei.h
• fs/dcache.c
• fs/namei.c
• fs/namespace.c

To build the kernel, use make menuconfig or copy a old Linux 3.14 config file into the linux-3.14 directory. By default, the dcache optimization is enabled, and set to default options. For more tuning in the dcache optimization, change the options in make menuconfig:

  -> File systems
      -> dcache optimization

After setting up the kernel options, use make and make install, or building tools such as make-kpkg to build and install the kernel. Basic knowledge and experience about building, installing and booting alternative Linux kernel is required.