* Mapping attached part of segment is done at attach time instead of
make time to work with runtimes (e.g. OpenMPI) xpmem_make-ing the
entire user-space
* Mapping attached part of segment at attach time can be turned off by
specifying xpmem_remote_on_demand in kernel argument
* Mapping attachment chooses appropriate page-sizes, i.e., largest
allowed by memory range and segment page boundary
Fixes: a8696d8 "xpmem: Support large page attachment"
Change-Id: I44663865204036520e5f62fe22b9134ee4629f9b
