MMap'd files, and... in-demand paging... are pretty much on every CPU architecture worth making an application for. ARM, POWER9, X86, SPARC, MIPS, and more.

In-demand paging is another situation where a simple pointer-dereference can suddenly turn into a filesystem (and therefore: kernel-level / hardware-level) call.

What the commenter above you was describing about mmap'ed files and dereferencing invoking the kernel implicitly -- that's true on all current CPU architectures (everything from x86 to SPARC to ARM and back again.)