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

- Add some comments to try to make the ifdef puzzle a bit clearer

- Explicitly inline one of the three init_hrtick() implementations.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/sched.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff -puN kernel/sched.c~sched-clarify-ifdef-tangle kernel/sched.c
--- a/kernel/sched.c~sched-clarify-ifdef-tangle
+++ a/kernel/sched.c
@@ -1112,7 +1112,7 @@ static void hrtick_start(struct rq *rq, 
 	hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay), HRTIMER_MODE_REL);
 }
 
-static void init_hrtick(void)
+static inline void init_hrtick(void)
 {
 }
 #endif /* CONFIG_SMP */
@@ -1131,7 +1131,7 @@ static void init_rq_hrtick(struct rq *rq
 	rq->hrtick_timer.function = hrtick;
 	rq->hrtick_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
 }
-#else
+#else	/* CONFIG_SCHED_HRTICK */
 static inline void hrtick_clear(struct rq *rq)
 {
 }
@@ -1143,7 +1143,7 @@ static inline void init_rq_hrtick(struct
 static inline void init_hrtick(void)
 {
 }
-#endif
+#endif	/* CONFIG_SCHED_HRTICK */
 
 /*
  * resched_task - mark a task 'to be rescheduled now'.
_