rcu: Eliminate unneeded function wrapping

The functions rcu_init() is a wrapper for __rcu_init(), and also
sets up the CPU-hotplug notifier for rcu_barrier_cpu_hotplug().
But TINY_RCU doesn't need CPU-hotplug notification, and the
rcu_barrier_cpu_hotplug() is a simple wrapper for
rcu_cpu_notify().

So push rcu_init() out to kernel/rcutree.c and kernel/rcutiny.c
and get rid of the wrapper function rcu_barrier_cpu_hotplug().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <12589088302320-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 14 insertions, 3 deletions

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index b79bfcd28e95..e3d3bbddbcd5 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1644,8 +1644,8 @@ static void __cpuinit rcu_online_cpu(int cpu)
 /*
  * Handle CPU online/offline notification events.
  */
-int __cpuinit rcu_cpu_notify(struct notifier_block *self,
-                             unsigned long action, void *hcpu)
+static int __cpuinit rcu_cpu_notify(struct notifier_block *self,
+                                    unsigned long action, void *hcpu)
 {
         long cpu = (long)hcpu;
 
@@ -1781,8 +1781,10 @@ do { \
         } \
 } while (0)
 
-void __init __rcu_init(void)
+void __init rcu_init(void)
 {
+        int i;
+
         rcu_bootup_announce();
 #ifdef CONFIG_RCU_CPU_STALL_DETECTOR
         printk(KERN_INFO "RCU-based detection of stalled CPUs is enabled.\n");
@@ -1791,6 +1793,15 @@ void __init __rcu_init(void)
         RCU_INIT_FLAVOR(&rcu_bh_state, rcu_bh_data);
         __rcu_init_preempt();
         open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
+
+        /*
+         * We don't need protection against CPU-hotplug here because
+         * this is called early in boot, before either interrupts
+         * or the scheduler are operational.
+         */
+        cpu_notifier(rcu_cpu_notify, 0);
+        for_each_online_cpu(i)
+                rcu_cpu_notify(NULL, CPU_UP_PREPARE, (void *)(long)i);
 }
 
 #include "rcutree_plugin.h"