1 files changed, 9 insertions, 6 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9673d96b1ba7..6a83cd35cfde 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4420,10 +4420,11 @@ static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
  * round what is now in bits to nearest long in bits, then return it in
  * bytes.
  */
-static unsigned long __init usemap_size(unsigned long zonesize)
+static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
 {
         unsigned long usemapsize;
 
+        zonesize += zone_start_pfn & (pageblock_nr_pages-1);
         usemapsize = roundup(zonesize, pageblock_nr_pages);
         usemapsize = usemapsize >> pageblock_order;
         usemapsize *= NR_PAGEBLOCK_BITS;
@@ -4433,17 +4434,19 @@ static unsigned long __init usemap_size(unsigned long zonesize)
 }
 
 static void __init setup_usemap(struct pglist_data *pgdat,
-                                struct zone *zone, unsigned long zonesize)
+                                struct zone *zone,
+                                unsigned long zone_start_pfn,
+                                unsigned long zonesize)
 {
-        unsigned long usemapsize = usemap_size(zonesize);
+        unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
         zone->pageblock_flags = NULL;
         if (usemapsize)
                 zone->pageblock_flags = alloc_bootmem_node_nopanic(pgdat,
                                                                    usemapsize);
 }
 #else
-static inline void setup_usemap(struct pglist_data *pgdat,
-                                struct zone *zone, unsigned long zonesize) {}
+static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
+                                unsigned long zone_start_pfn, unsigned long zonesize) {}
 #endif /* CONFIG_SPARSEMEM */
 
 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
@@ -4594,7 +4597,7 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
                         continue;
 
                 set_pageblock_order();
-                setup_usemap(pgdat, zone, size);
+                setup_usemap(pgdat, zone, zone_start_pfn, size);
                 ret = init_currently_empty_zone(zone, zone_start_pfn,
                                                 size, MEMMAP_EARLY);
                 BUG_ON(ret);