smaller than sv48, the CPU maximum supported address space will be the default.
Software can "opt-in" to receiving VAs from another VA space by providing
-a hint address to mmap. A hint address passed to mmap will cause the largest
-address space that fits entirely into the hint to be used, unless there is no
-space left in the address space. If there is no space available in the requested
-address space, an address in the next smallest available address space will be
-returned.
-
-For example, in order to obtain 48-bit VA space, a hint address greater than
-:code:`1 << 47` must be provided. Note that this is 47 due to sv48 userspace
-ending at :code:`1 << 47` and the addresses beyond this are reserved for the
-kernel. Similarly, to obtain 57-bit VA space addresses, a hint address greater
-than or equal to :code:`1 << 56` must be provided.
+a hint address to mmap. When a hint address is passed to mmap, the returned
+address will never use more bits than the hint address. For example, if a hint
+address of `1 << 40` is passed to mmap, a valid returned address will never use
+bits 41 through 63. If no mappable addresses are available in that range, mmap
+will return `MAP_FAILED`.