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authorThomas Schwinge <tschwinge@gnu.org>2007-02-04 14:09:30 +0000
committerThomas Schwinge <tschwinge@gnu.org>2009-06-18 00:27:02 +0200
commit8f8ef5d5634f5ae4d43c46044555dba1073f5f9a (patch)
tree313577234da5c721d0249a328bc9180cf2471558 /kern
parent8005e98d3e6a6c1204803e4c2013863eba9571f4 (diff)
2007-02-04 Thomas Schwinge <tschwinge@gnu.org>
* kern/timer.h: Add some comments from... * i386/i386/timer.h: ... here and remove this file.
Diffstat (limited to 'kern')
-rw-r--r--kern/timer.h27
1 files changed, 27 insertions, 0 deletions
diff --git a/kern/timer.h b/kern/timer.h
index 4146237..4018236 100644
--- a/kern/timer.h
+++ b/kern/timer.h
@@ -36,10 +36,37 @@
* as a result. Service timers once an hour.
*/
+/*
+ * TIMER_MAX is needed if a 32-bit rollover timer needs to be adjusted for
+ * maximum value.
+ */
+#undef TIMER_MAX
+
+/*
+ * TIMER_RATE is the rate of the timer in ticks per second. It is used to
+ * calculate percent cpu usage.
+ */
#define TIMER_RATE 1000000
+
+/*
+ * TIMER_HIGH_UNIT is the unit for high_bits in terms of low_bits.
+ * Setting it to TIMER_RATE makes the high unit seconds.
+ */
#define TIMER_HIGH_UNIT TIMER_RATE
+
+/*
+ * TIMER_ADJUST is used to adjust the value of a timer after it has been
+ * copied into a time_value_t. No adjustment is needed if high_bits is in
+ * seconds.
+ */
#undef TIMER_ADJUST
+/*
+ * MACHINE_TIMER_ROUTINES should defined if the timer routines are
+ * implemented in machine-dependent code (e.g. assembly language).
+ */
+#undef MACHINE_TIMER_ROUTINES
+
#else /* STAT_TIME */
/*
* Machine dependent definitions based on hardware support.