This is the general todo list for the page_replace work:

 * port the page replace policy code to -mm this includes adding some abstractions in order to accommodate the swap migration work of christoph lameter.
 * port the CART policies (with and without cyclic extension) to the shiny new policy framework.
 * come up with good benchmarks showing both:
     1. that the new code doesn't degrade performance; and
     2. that it does improve the expected scenarios.
 * document it.
 * have I mentioned benchmarks?
 * trick andrew to accept the patches.