[PATCH] rcutree: Fix v3.4-rc2-rt2 build break

[John Kacur <jkacur@redhat.com>]

Fix build break of the following types.

linux-rt/kernel/rcutree_plugin.h: In function ‘print_cpu_stall_fast_no_hz’:
linux-rt/kernel/rcutree_plugin.h:2195: error: ‘rcu_idle_gp_timer’ undeclared (first use in this function)
linux-rt/kernel/rcutree_plugin.h:2195: error: (Each undeclared identifier is reported only once
linux-rt/kernel/rcutree_plugin.h:2195: error: for each function it appears in.)

The build break only occurs with the PREEMPT_RT_FULL patch applied, however
the patch is meant to go upstream and be applied to v3.4-rc2 as well because
it makes the code more legible there, and will reduce the number of places
where #ifdef PREEMPT_RT_FULL is required should that go upstream someday.

Signed-off-by: John Kacur <jkacur@redhat.com>
---
 kernel/rcutree_plugin.h |   19 +++++++++----------
 1 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 14acafc..1db9471 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -1938,6 +1938,12 @@ static void rcu_prepare_for_idle(int cpu)
 {
 }
 
+#ifdef CONFIG_RCU_CPU_STALL_INFO
+static void print_cpu_stall_fast_no_hz(char *cp, int cpu)
+{
+}
+#endif /* #ifdef CONFIG_RCU_CPU_STALL_INFO */
+
 #else /* #if !defined(CONFIG_RCU_FAST_NO_HZ) */
 
 /*
@@ -2184,12 +2190,8 @@ static void rcu_prepare_for_idle(int cpu)
 		trace_rcu_prep_idle("Callbacks drained");
 }
 
-#endif /* #else #if !defined(CONFIG_RCU_FAST_NO_HZ) */
 
 #ifdef CONFIG_RCU_CPU_STALL_INFO
-
-#ifdef CONFIG_RCU_FAST_NO_HZ
-
 static void print_cpu_stall_fast_no_hz(char *cp, int cpu)
 {
 	struct hrtimer *hrtp = &per_cpu(rcu_idle_gp_timer, cpu);
@@ -2201,14 +2203,11 @@ static void print_cpu_stall_fast_no_hz(char *cp, int cpu)
 			? ktime_to_us(hrtimer_get_remaining(hrtp))
 			: -1);
 }
+#endif /* #ifdef CONFIG_RCU_CPU_STALL_INFO */
 
-#else /* #ifdef CONFIG_RCU_FAST_NO_HZ */
-
-static void print_cpu_stall_fast_no_hz(char *cp, int cpu)
-{
-}
+#endif /* #else #if !defined(CONFIG_RCU_FAST_NO_HZ) */
 
-#endif /* #else #ifdef CONFIG_RCU_FAST_NO_HZ */
+#ifdef CONFIG_RCU_CPU_STALL_INFO
 
 /* Initiate the stall-info list. */
 static void print_cpu_stall_info_begin(void)
-- 
1.7.2.3