Clarify.

diff --git a/doc/threads.texi b/doc/threads.texi
index b177d43adbb093ef5b4b9fedd0965a93061a89b5..a544b78f06522fd89a27a76a2ea0c598b0bbbf3b 100644 (file)
--- a/doc/threads.texi
+++ b/doc/threads.texi
@@ -487,8 +487,9 @@ that @var{L} holds, then both @var{M} and @var{L} should be boosted to
 
 You only need to implement priority donation when a thread is waiting
 for a lock held by a lower-priority thread.  You do not need to
-implement this fix for semaphores, condition variables, or joins.
-However, you do need to implement priority scheduling in all cases.
+implement this fix for semaphores, condition variables, or joins,
+although you are welcome to do so.  However, you do need to implement
+priority scheduling in all cases.
 
 You may assume a static priority for priority donation, that is, it is
 not necessary to ``re-donate'' a thread's priority if it changes