--- /sys/src/9/port/watermarks.c	Tue Mar 11 20:44:26 2014
+++ /sys/src/9/port/watermarks.c	Wed Mar 12 23:28:13 2014
@@ -1,3 +1,6 @@
+/*
+ * high-watermark measurements
+ */
 #include	"u.h"
 #include	"../port/lib.h"
 #include	"mem.h"