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-rw-r--r--xen-2.4.16/include/xeno/timer.h9
1 files changed, 8 insertions, 1 deletions
diff --git a/xen-2.4.16/include/xeno/timer.h b/xen-2.4.16/include/xeno/timer.h
index c4f01ada59..dcde75b182 100644
--- a/xen-2.4.16/include/xeno/timer.h
+++ b/xen-2.4.16/include/xeno/timer.h
@@ -12,10 +12,17 @@
* The "data" field enables use of a common timeout function for several
* timeouts. You can use this field to distinguish between the different
* invocations.
+ *
+ * RN: Unlike the Linux timers, which are executed at the periodic timer
+ * interrupt, in Xen, the timer list is only checked "occasionally", thus
+ * its accuracy might be somewhat worse than under Linux. However, the
+ * hypervisor should be purely event-driven and, in fact, in the current
+ * implementation, timers are only used for watchdog purpose at a very
+ * coarse granularity anyway. Thus this is not a problem.
*/
struct timer_list {
struct list_head list;
- unsigned long expires;
+ unsigned long expires; /* jiffies */
unsigned long data;
void (*function)(unsigned long);
};