From: Andrew Morton <akpm@linux-foundation.org>

It uses hrtimers.

Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/tick.h |    1 +
 1 file changed, 1 insertion(+)

diff -puN include/linux/tick.h~git-acpi-tickh-needs-hrtimerh include/linux/tick.h
--- a/include/linux/tick.h~git-acpi-tickh-needs-hrtimerh
+++ a/include/linux/tick.h
@@ -7,6 +7,7 @@
 #define _LINUX_TICK_H
 
 #include <linux/clockchips.h>
+#include <linux/hrtimer.h>
 
 #ifdef CONFIG_GENERIC_CLOCKEVENTS
 
_