+#
+/*
+ * Clock handling routines.
+ *
+ * This code is written for a machine with only one interval timer,
+ * and does timing and resource utilization estimation statistically
+ * based on the state of the machine hz times a second. A machine
+ * with proper clocks (running separately in user state, system state,
+ * interrupt state and idle state) as well as a time-of-day clock
+ * would allow a non-approximate implementation.
+ */
+
+/*
+ * TODO:
+ * * Keep more accurate statistics by simulating good interval timers.
+ * * Use the time-of-day clock on the VAX to keep more accurate time
+ * than is possible by repeated use of the interval timer.
+ * * Allocate more timeout table slots when table overflows.
+ */
+
+/* bump a timeval by a small number of usec's */
+#define bumptime(tp, usec) \
+ (tp)->tv_usec += usec; \