memory hotplug: fix unnecessary calling of init_currenty_empty_zone()

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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 8427912..df9d554 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -65,7 +65,7 @@ static int __add_zone(struct zone *zone, unsigned long phys_start_pfn)
        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);