From: Yasunori Goto <y-goto@jp.fujitsu.com>

zone->present_pages is updated in online_pages().  But, __add_zone() can be
called twice or more before calling online_pages().  So,
init_currenty_empty_zone() can be called unnecessary times.  It is cause of
memory leak of zone's wait_table.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memory_hotplug.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN mm/memory_hotplug.c~memory-hotplug-fix-unnecessary-calling-of-init_currenty_empty_zone mm/memory_hotplug.c
--- a/mm/memory_hotplug.c~memory-hotplug-fix-unnecessary-calling-of-init_currenty_empty_zone
+++ a/mm/memory_hotplug.c
@@ -65,7 +65,7 @@ static int __add_zone(struct zone *zone,
 	int zone_type;
 
 	zone_type = zone - pgdat->node_zones;
-	if (!populated_zone(zone)) {
+	if (!zone->wait_table) {
 		int ret = 0;
 		ret = init_currently_empty_zone(zone, phys_start_pfn,
 						nr_pages, MEMMAP_HOTPLUG);
_