Move hotplug_cfd() to the end of the file so that we can see what changes

the next patch (generic-ipi: fix the race between
generic_smp_call_function_*() and hotplug_cfd()) actually makes to that
function.

Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

kernel/smp.c

@@ -40,57 +40,6 @@ struct call_single_queue {
 
 static DEFINE_PER_CPU(struct call_function_data, cfd_data);
 
-static int
-hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
-{
-	long cpu = (long)hcpu;
-	struct call_function_data *cfd = &per_cpu(cfd_data, cpu);
-
-	switch (action) {
-	case CPU_UP_PREPARE:
-	case CPU_UP_PREPARE_FROZEN:
-		if (!zalloc_cpumask_var_node(&cfd->cpumask, GFP_KERNEL,
-				cpu_to_node(cpu)))
-			return NOTIFY_BAD;
-		break;
-
-#ifdef CONFIG_HOTPLUG_CPU
-	case CPU_UP_CANCELED:
-	case CPU_UP_CANCELED_FROZEN:
-
-	case CPU_DEAD:
-	case CPU_DEAD_FROZEN:
-		free_cpumask_var(cfd->cpumask);
-		break;
-#endif
-	};
-
-	return NOTIFY_OK;
-}
-
-static struct notifier_block __cpuinitdata hotplug_cfd_notifier = {
-	.notifier_call		= hotplug_cfd,
-};
-
-static int __cpuinit init_call_single_data(void)
-{
-	void *cpu = (void *)(long)smp_processor_id();
-	int i;
-
-	for_each_possible_cpu(i) {
-		struct call_single_queue *q = &per_cpu(call_single_queue, i);
-
-		spin_lock_init(&q->lock);
-		INIT_LIST_HEAD(&q->list);
-	}
-
-	hotplug_cfd(&hotplug_cfd_notifier, CPU_UP_PREPARE, cpu);
-	register_cpu_notifier(&hotplug_cfd_notifier);
-
-	return 0;
-}
-early_initcall(init_call_single_data);
-
 /*
  * csd_lock/csd_unlock used to serialize access to per-cpu csd resources
  *
@@ -489,3 +438,54 @@ void ipi_call_unlock_irq(void)
 {
 	spin_unlock_irq(&call_function.lock);
 }
+
+static int
+hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+	long cpu = (long)hcpu;
+	struct call_function_data *cfd = &per_cpu(cfd_data, cpu);
+
+	switch (action) {
+	case CPU_UP_PREPARE:
+	case CPU_UP_PREPARE_FROZEN:
+		if (!zalloc_cpumask_var_node(&cfd->cpumask, GFP_KERNEL,
+				cpu_to_node(cpu)))
+			return NOTIFY_BAD;
+		break;
+
+#ifdef CONFIG_HOTPLUG_CPU
+	case CPU_UP_CANCELED:
+	case CPU_UP_CANCELED_FROZEN:
+
+	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
+		free_cpumask_var(cfd->cpumask);
+		break;
+#endif
+	};
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block __cpuinitdata hotplug_cfd_notifier = {
+	.notifier_call		= hotplug_cfd,
+};
+
+static int __cpuinit init_call_single_data(void)
+{
+	void *cpu = (void *)(long)smp_processor_id();
+	int i;
+
+	for_each_possible_cpu(i) {
+		struct call_single_queue *q = &per_cpu(call_single_queue, i);
+
+		spin_lock_init(&q->lock);
+		INIT_LIST_HEAD(&q->list);
+	}
+
+	hotplug_cfd(&hotplug_cfd_notifier, CPU_UP_PREPARE, cpu);
+	register_cpu_notifier(&hotplug_cfd_notifier);
+
+	return 0;
+}
+early_initcall(init_call_single_data);