• CompressedCaching
• Code

[:NitinGupta:Nitin Gupta]

MailTo(nitingupta910 AT gmail DOT com)

• This page contains some prototype code developed for CompressedCaching project. After seriously insufficient testing, each of these components were eventually merged into final implementation on 2.6.x kernels.

Compression algorithms to kernel mode:

Kernel module to test de/compression algorithms (WKdm, WK4x4, LZO): attachment:compress-test.tar.gz

There are basically three main algorithms that are well studied w.r.t compressed caching by previous works -- WKdm, WK4x4, LZO.

Of these, WKdm, WK4x4 are designed to handle anon pages (non filesystem pages) while LZO is more suitable for filesystem data. (Also, in general, compression speed is in order: WKdm > WK4x4 > LZO, while compression factor order is, in general, reverse).

Now, all three algos are ported to kernel space - WKdm, WK4x4 and LZO. You can test them all using this module. It creates 3 /proc entries: /proc/compress-test/{compress, decompress, algo_idx} as described below: (for some detail see README with this module)

In short:

Write to /proc/compress-test entries:

1. compress: compress data witten to it and store in internal buffer.

2. algo_idx: write index of algo you want to test (0: WKdm, 1: WK4x4, 2: LZO)

Read from /proc/compress-test entries:

1. compress: show original and compressed size (TODO: add other stats like time taken too)

2. decompress: decompress compressed data stored in internal buffer.

3. algo_idx: shows list of algos supported with their index.