On Fri, 2010-04-30 at 08:59 -0700, Dan Magenheimer wrote:
> Dave or others can correct me if I am wrong, but I think CMM2 also
> handles dirty pages that must be retained by the hypervisor.  The
> difference between CMM2 (for dirty pages) and frontswap is that
> CMM2 sets hints that can be handled asynchronously while frontswap
> provides explicit hooks that synchronously succeed/fail.

Once pages were dirtied (or I guess just slightly before), they became
volatile, and I don't think the hypervisor could do anything with them.
It could still swap them out like usual, but none of the CMM-specific
optimizations could be performed.

CC'ing Martin since he's the expert. :)

-- Dave