[namibj]

mmap is also for non-disk-backed memory:

Your link refers to https://www.kernel.org/doc/Documentation/admin-guide/mm/huge... ,

which contains this tidbit:

> If the user applications are going to request huge pages using mmap system call, then it is required that system administrator mount a file system of type hugetlbfs::

Note this otherwise has semantics similar to tmpfs; notably, it's usage is mutually exclusive with being able to supply a disk file fd to mmap!