ksm demo

It's not transparent to users: Any program that want to benefit from KSM should explicitly submit its memory area to the kernel. But very often, a common user/programmer does not understand the possibility for his program being deduplicated. And there are still many programs you don't have or want to modify their source code.

It's still not smart enough: It scan memory areas at some given speed constantly. But ideally, you don't want to waste your CPU when all the memory areas have no duplicated pages.

It's still not fast enough: It's official top merging speed is about 260M/s, we think we can do much better than that.

So here comes UKSM, removing all these limitations. If you are interested in KSM, you definitely also want to have a look at the features of UKSM !
https://code.google.com/p/uksm/