[$] Sidestepping kernel memory management with DMEMFS

One of the kernel's primary jobs is to manage the memory installed in thesystem. Over the years, though, there have been various reasons forremoving a portion of the system's memory from the kernel's view. One ofthe latest can be seen in a mechanism called DMEMFS,which is being proposed as a way to get around some inefficiency in how thekernel keeps track of RAM.