+
+ /* If there are no fractional seconds, don't print any decimals.
+ *
+ * If the fractional seconds can be expressed exactly as milliseconds,
+ * print 3 decimals. Open vSwitch provides millisecond precision for most
+ * time measurements, so printing 3 decimals every time makes it easier to
+ * spot real changes in flow dumps that refresh themselves quickly.
+ *
+ * If the fractional seconds are more precise than milliseconds, print the
+ * number of decimals needed to express them exactly.
+ */