x86: change NR_CPUS arrays in smpboot_64

Change the following static arrays sized by NR_CPUS to
per_cpu data variables:

	task_struct *idle_thread_array[NR_CPUS];

This is only done if CONFIG_HOTPLUG_CPU is defined
as otherwise, the array is removed after initialization
anyways.

Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/smpboot_64.c

@@ -111,10 +111,20 @@ DEFINE_PER_CPU(int, cpu_state) = { 0 };
  * a new thread. Also avoids complicated thread destroy functionality
  * for idle threads.
  */
+#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * Needed only for CONFIG_HOTPLUG_CPU because __cpuinitdata is
+ * removed after init for !CONFIG_HOTPLUG_CPU.
+ */
+static DEFINE_PER_CPU(struct task_struct *, idle_thread_array);
+#define get_idle_for_cpu(x)     (per_cpu(idle_thread_array, x))
+#define set_idle_for_cpu(x,p)   (per_cpu(idle_thread_array, x) = (p))
+#else
 struct task_struct *idle_thread_array[NR_CPUS] __cpuinitdata ;
-
 #define get_idle_for_cpu(x)     (idle_thread_array[(x)])
 #define set_idle_for_cpu(x,p)   (idle_thread_array[(x)] = (p))
+#endif
+
 
 /*
  * Currently trivial. Write the real->protected mode