[PATCH] cpu hotplug: make [un]register_cpu_notifier init time only

CPUs come online only at init time (unless CONFIG_HOTPLUG_CPU is defined).
So, cpu_notifier functionality need to be available only at init time.

This patch makes register_cpu_notifier() available only at init time, unless
CONFIG_HOTPLUG_CPU is defined.

This patch exports register_cpu_notifier() and unregister_cpu_notifier() only
if CONFIG_HOTPLUG_CPU is defined.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 3 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 03dcd981846a..70fbf2e83766 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -18,7 +18,7 @@
 /* This protects CPUs going up and down... */
 static DEFINE_MUTEX(cpucontrol);
 
-static BLOCKING_NOTIFIER_HEAD(cpu_chain);
+static __cpuinitdata BLOCKING_NOTIFIER_HEAD(cpu_chain);
 
 #ifdef CONFIG_HOTPLUG_CPU
 static struct task_struct *lock_cpu_hotplug_owner;
@@ -69,10 +69,13 @@ EXPORT_SYMBOL_GPL(lock_cpu_hotplug_interruptible);
 #endif  /* CONFIG_HOTPLUG_CPU */
 
 /* Need to know about CPUs going up/down? */
-int register_cpu_notifier(struct notifier_block *nb)
+int __cpuinit register_cpu_notifier(struct notifier_block *nb)
 {
         return blocking_notifier_chain_register(&cpu_chain, nb);
 }
+
+#ifdef CONFIG_HOTPLUG_CPU
+
 EXPORT_SYMBOL(register_cpu_notifier);
 
 void unregister_cpu_notifier(struct notifier_block *nb)
@@ -81,7 +84,6 @@ void unregister_cpu_notifier(struct notifier_block *nb)
 }
 EXPORT_SYMBOL(unregister_cpu_notifier);
 
-#ifdef CONFIG_HOTPLUG_CPU
 static inline void check_for_tasks(int cpu)
 {
         struct task_struct *p;