[no subject]

[Eugenio Pérez]

Please review this new minimal version. It is way shorter, but this
comes with a cost:
* Iteration does not stop at the end of range (but an out of range
  allocation never happens)
* Iteration must start from iova == 0 instead of first valid entry in
  the hole.

These should not be a big deal though.

Another possible optimization that comes to my mind is to allocate
always at the end of range. In the case of having to allocate and
deallocate frequently, this should avoid to iterate over long lived
entries. Better justify this with numbers, so I left that out.

Thanks!