Add Fast User Mutexes (futexes) to kernel-locking docbook.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Acked-by: NRob Landley <rob@landley.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>