Pull miscellaneous into release branch

[linux.git] / Documentation / nommu-mmap.txt

diff --git a/Documentation/nommu-mmap.txt b/Documentation/nommu-mmap.txt
index 3ce89066493606eb30b0e2748f2130f99a8a7833..7714f57caad5b4312e7289761c0561c68b822049 100644 (file)
--- a/Documentation/nommu-mmap.txt
+++ b/Documentation/nommu-mmap.txt
@@ -129,6 +129,25 @@ FURTHER NOTES ON NO-MMU MMAP
      with character device files, pipes, fifos and sockets.
 
 
+==========================
+INTERPROCESS SHARED MEMORY
+==========================
+
+Both SYSV IPC SHM shared memory and POSIX shared memory is supported in NOMMU
+mode.  The former through the usual mechanism, the latter through files created
+on ramfs or tmpfs mounts.
+
+
+=======
+FUTEXES
+=======
+
+Futexes are supported in NOMMU mode if the arch supports them.  An error will
+be given if an address passed to the futex system call lies outside the
+mappings made by a process or if the mapping in which the address lies does not
+support futexes (such as an I/O chardev mapping).
+
+
 =============
 NO-MMU MREMAP
 =============