[PATCH] wait_table and zonelist initializing for memory hotadd: add return code for init_current_empty_zone

When add_zone() is called against empty zone (not populated zone), we have to
initialize the zone which didn't initialize at boot time.  But,
init_currently_empty_zone() may fail due to allocation of wait table.  So,
this patch is to catch its error code.

Changes against wait_table is in the next patch.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 24 insertions, 5 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 652673ea92f..e82fc1a52cd 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -333,6 +333,9 @@ void wakeup_kswapd(struct zone *zone, int order);
 int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
                 int classzone_idx, int alloc_flags);
 
+extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
+                                     unsigned long size);
+
 #ifdef CONFIG_HAVE_MEMORY_PRESENT
 void memory_present(int nid, unsigned long start, unsigned long end);
 #else
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 70df5c0d957..71da5c98c9c 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -26,7 +26,7 @@
 
 extern void zonetable_add(struct zone *zone, int nid, int zid, unsigned long pfn,
                           unsigned long size);
-static void __add_zone(struct zone *zone, unsigned long phys_start_pfn)
+static int __add_zone(struct zone *zone, unsigned long phys_start_pfn)
 {
         struct pglist_data *pgdat = zone->zone_pgdat;
         int nr_pages = PAGES_PER_SECTION;
@@ -34,8 +34,15 @@ static void __add_zone(struct zone *zone, unsigned long phys_start_pfn)
         int zone_type;
 
         zone_type = zone - pgdat->node_zones;
+        if (!populated_zone(zone)) {
+                int ret = 0;
+                ret = init_currently_empty_zone(zone, phys_start_pfn, nr_pages);
+                if (ret < 0)
+                        return ret;
+        }
         memmap_init_zone(nr_pages, nid, zone_type, phys_start_pfn);
         zonetable_add(zone, nid, zone_type, phys_start_pfn, nr_pages);
+        return 0;
 }
 
 extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
@@ -50,7 +57,11 @@ static int __add_section(struct zone *zone, unsigned long phys_start_pfn)
         if (ret < 0)
                 return ret;
 
-        __add_zone(zone, phys_start_pfn);
+        ret = __add_zone(zone, phys_start_pfn);
+
+        if (ret < 0)
+                return ret;
+
         return register_new_memory(__pfn_to_section(phys_start_pfn));
 }
 
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 5ae75bead4d..4bc66f6b771 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2050,8 +2050,9 @@ static __meminit void zone_pcp_init(struct zone *zone)
                         zone->name, zone->present_pages, batch);
 }
 
-static __meminit void init_currently_empty_zone(struct zone *zone,
-                unsigned long zone_start_pfn, unsigned long size)
+__meminit int init_currently_empty_zone(struct zone *zone,
+                                        unsigned long zone_start_pfn,
+                                        unsigned long size)
 {
         struct pglist_data *pgdat = zone->zone_pgdat;
 
@@ -2063,6 +2064,8 @@ static __meminit void init_currently_empty_zone(struct zone *zone,
         memmap_init(size, pgdat->node_id, zone_idx(zone), zone_start_pfn);
 
         zone_init_free_lists(pgdat, zone, zone->spanned_pages);
+
+        return 0;
 }
 
 /*
@@ -2077,6 +2080,7 @@ static void __meminit free_area_init_core(struct pglist_data *pgdat,
         unsigned long j;
         int nid = pgdat->node_id;
         unsigned long zone_start_pfn = pgdat->node_start_pfn;
+        int ret;
 
         pgdat_resize_init(pgdat);
         pgdat->nr_zones = 0;
@@ -2118,7 +2122,8 @@ static void __meminit free_area_init_core(struct pglist_data *pgdat,
                         continue;
 
                 zonetable_add(zone, nid, j, zone_start_pfn, size);
-                init_currently_empty_zone(zone, zone_start_pfn, size);
+                ret = init_currently_empty_zone(zone, zone_start_pfn, size);
+                BUG_ON(ret);
                 zone_start_pfn += size;
         }
 }