Dynamic compression of swap pages and clean pagecache pages

modulename:  zcache.ko

configname: CONFIG_ZCACHE2

Linux Kernel Configuration
└─>Device Drivers
└─>Staging drivers
└─>Dynamic compression of swap pages and clean pagecache pages
In linux kernel since version 3.7 (release Date: 2012-12-10)  
Zcache2 doubles RAM efficiency while providing a significant
performance boosts on many workloads. Zcache2 uses
compression and an in-kernel implementation of transcendent
memory to store clean page cache pages and swap in RAM,
providing a noticeable reduction in disk I/O. Zcache2
is a complete rewrite of the older zcache; it was intended to
be a merge but that has been blocked due to political and
technical disagreements. It is intended that they will merge
again in the future. Until then, zcache2 is a single-node
version of ramster.

source code: