1 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index 0616ffe45702..03f3b05e8ec1 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -75,6 +75,17 @@ do {								\
 } while (0)
 
 /*
+ * This is the same regardless of which rwsem implementation that is being used.
+ * It is just a heuristic meant to be called by somebody alreadying holding the
+ * rwsem to see if somebody from an incompatible type is wanting access to the
+ * lock.
+ */
+static inline int rwsem_is_contended(struct rw_semaphore *sem)
+{
+        return !list_empty(&sem->wait_list);
+}
+
+/*
  * lock for reading
  */
 extern void down_read(struct rw_semaphore *sem);