From: Arjan van de Ven <arjan@linux.intel.com>

It's nice to say that mutex_trylock follows the spin_trylock convention. 
It's a lot nicer if the comment also says which that is...  make it so.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/mutex.h |    2 ++
 1 file changed, 2 insertions(+)

diff -puN include/linux/mutex.h~mutex-improve-header-comment-to-be-actually-informative-about-the-api include/linux/mutex.h
--- a/include/linux/mutex.h~mutex-improve-header-comment-to-be-actually-informative-about-the-api
+++ a/include/linux/mutex.h
@@ -144,6 +144,8 @@ extern int __must_check mutex_lock_killa
 /*
  * NOTE: mutex_trylock() follows the spin_trylock() convention,
  *       not the down_trylock() convention!
+ *
+ * Returns 1 if the mutex has been acquired successfully, and 0 on contention.
  */
 extern int mutex_trylock(struct mutex *lock);
 extern void mutex_unlock(struct mutex *lock);
_