[PATCH] hot-add-mem x86_64: use CONFIG_MEMORY_HOTPLUG_RESERVE

The api for hot-add memory already has a construct for finding nodes based on
an address, memory_add_physaddr_to_nid.  This patch allows the fucntion to do
something besides return 0.  It uses the nodes_add infomation to lookup to
node info for a hot add event.

Signed-off-by: Keith Mannthey <kmannth@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c
index 71ecbb3..19c7252 100644
--- a/arch/x86_64/mm/init.c
+++ b/arch/x86_64/mm/init.c
@@ -474,12 +474,12 @@
 	unsigned long nr_pages = size >> PAGE_SHIFT;
 	int ret;
 
+	init_memory_mapping(start, (start + size -1));
+
 	ret = __add_pages(zone, start_pfn, nr_pages);
 	if (ret)
 		goto error;
 
-	init_memory_mapping(start, (start + size -1));
-
 	return ret;
 error:
 	printk("%s: Problem encountered in __add_pages!\n", __func__);
@@ -501,7 +501,16 @@
 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 #endif
 
-#else /* CONFIG_MEMORY_HOTPLUG */
+#ifndef CONFIG_ACPI_NUMA
+int memory_add_physaddr_to_nid(u64 start)
+{
+	return 0;
+}
+#endif
+
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
+#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
 /*
  * Memory Hotadd without sparsemem. The mem_maps have been allocated in advance,
  * just online the pages.
@@ -527,7 +536,7 @@
 	}
 	return err;
 }
-#endif /* CONFIG_MEMORY_HOTPLUG */
+#endif
 
 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel, kcore_modules,
 			 kcore_vsyscall;