This needs a lot of testing on changing values such as:
gc_elasticity , max_size , gc_thresh , gc_min_interval
More for reading here:
http://lkml.indiana.edu/hypermail/linux/kernel/9901.3/1121.html
http://mailman.ds9a.nl/pipermail/lartc/2002q4/005296.html
http://lwn.net/Articles/145406/