you actually can already try it today (already well-tested with ext4 & btrfs):
22.214.171.124_plus_v1: BFS, CFS,THP,compaction, zcache or TOI
I would like to try the new zcache implementation that is inside th new 2.6.39 kernel (waiting for the cleancache merge in 2.6.39-rc2).
Look here for specs: http://lwn.net/Articles/397574/
Form the point of view of performance, the authors of the patches showed this:
I think thi look promising.
for those who want to test a more recent kernel (126.96.36.199-zen*) with zcache:
zcache + fixes + make btrfs work and tweaks & improvements to zram (included in 2.6.39)
to be applied on top of 188.8.131.52-zen*
zcache_184.108.40.206_zen.txt (154.26 KB)