Index: pipe.h
===================================================================
--- pipe.h	(revision 229942)
+++ pipe.h	(working copy)
@@ -138,5 +138,7 @@ struct pipepair {
 #define PIPE_UNLOCK(pipe)	mtx_unlock(PIPE_MTX(pipe))
 #define PIPE_LOCK_ASSERT(pipe, type)  mtx_assert(PIPE_MTX(pipe), (type))
 
+#define	PIPE_CNT(pipe)	(((pipe)->pipe_state & PIPE_DIRECTW) ?		\
+			    (pipe)->pipe_map.cnt : (pipe)->pipe_buffer.cnt)
 
 #endif /* !_SYS_PIPE_H_ */