The comment is copied from Documentation/rbtree.txt, but this comment is
so important that it should also be in the code.
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: NMichel Lespinasse <walken@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>