-/* Some systems don't provide MAP_FAILED, a symbolic constant for the
- value returned by mmap() when it doesn't work. Usually, this
- constant should be -1. This only makes sense for files that use
- mmap() and include sys/mman.h *before* sysdep.h, but doesn't hurt
- others. */
+/* Some systems (Linux libc5, "NCR MP-RAS 3.0", and others) don't
+ provide MAP_FAILED, a symbolic constant for the value returned by
+ mmap() when it doesn't work. Usually, this constant should be -1.
+ This only makes sense for files that use mmap() and include
+ sys/mman.h *before* sysdep.h, but doesn't hurt others. */