memory hotplug: memmap_init_zone called twice

__add_zone calls memmap_init_zone twice if memory gets attached to an empty
zone.  Once via init_currently_empty_zone and once explictly right after that
call.

Looks like this is currently not a bug, however the call is superfluous and
might lead to subtle bugs if memmap_init_zone gets changed.  So make sure it
is called only once.

Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 7 deletions

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index b17dca7249f8..988bd91b9f7f 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -167,13 +167,9 @@ static int __add_zone(struct zone *zone, unsigned long phys_start_pfn)
         int zone_type;
 
         zone_type = zone - pgdat->node_zones;
-        if (!zone->wait_table) {
-                int ret = 0;
-                ret = init_currently_empty_zone(zone, phys_start_pfn,
-                                                nr_pages, MEMMAP_HOTPLUG);
-                if (ret < 0)
-                        return ret;
-        }
+        if (!zone->wait_table)
+                return init_currently_empty_zone(zone, phys_start_pfn,
+                                                 nr_pages, MEMMAP_HOTPLUG);
         memmap_init_zone(nr_pages, nid, zone_type,
                          phys_start_pfn, MEMMAP_HOTPLUG);
         return 0;