2 files changed, 55 insertions, 5 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index a8140a9a65e8..9a5d5590bd39 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -748,7 +748,7 @@ extern struct zone *next_zone(struct zone *zone);
 #define PAGE_SECTION_MASK       (~(PAGES_PER_SECTION-1))
 
 #define SECTION_BLOCKFLAGS_BITS \
-                ((SECTION_SIZE_BITS - (MAX_ORDER-1)) * NR_PAGEBLOCK_BITS)
+                ((1 << (PFN_SECTION_SHIFT - (MAX_ORDER-1))) * NR_PAGEBLOCK_BITS)
 
 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
 #error Allocator MAX_ORDER exceeds SECTION_SIZE
@@ -769,7 +769,9 @@ struct mem_section {
          * before using it wrong.
          */
         unsigned long section_mem_map;
-        DECLARE_BITMAP(pageblock_flags, SECTION_BLOCKFLAGS_BITS);
+
+        /* See declaration of similar field in struct zone */
+        unsigned long *pageblock_flags;
 };
 
 #ifdef CONFIG_SPARSEMEM_EXTREME
diff --git a/mm/sparse.c b/mm/sparse.c
index 52843a76feed..1f4dbb867b8a 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -206,7 +206,8 @@ struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pn
 }
 
 static int __meminit sparse_init_one_section(struct mem_section *ms,
-                unsigned long pnum, struct page *mem_map)
+                unsigned long pnum, struct page *mem_map,
+                unsigned long *pageblock_bitmap)
 {
         if (!present_section(ms))
                 return -EINVAL;
@@ -214,6 +215,7 @@ static int __meminit sparse_init_one_section(struct mem_section *ms,
         ms->section_mem_map &= ~SECTION_MAP_MASK;
         ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) |
                                                         SECTION_HAS_MEM_MAP;
+        ms->pageblock_flags = pageblock_bitmap;
 
         return 1;
 }
@@ -224,6 +226,38 @@ void *alloc_bootmem_high_node(pg_data_t *pgdat, unsigned long size)
         return NULL;
 }
 
+static unsigned long usemap_size(void)
+{
+        unsigned long size_bytes;
+        size_bytes = roundup(SECTION_BLOCKFLAGS_BITS, 8) / 8;
+        size_bytes = roundup(size_bytes, sizeof(unsigned long));
+        return size_bytes;
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+static unsigned long *__kmalloc_section_usemap(void)
+{
+        return kmalloc(usemap_size(), GFP_KERNEL);
+}
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
+static unsigned long *sparse_early_usemap_alloc(unsigned long pnum)
+{
+        unsigned long *usemap;
+        struct mem_section *ms = __nr_to_section(pnum);
+        int nid = sparse_early_nid(ms);
+
+        usemap = alloc_bootmem_node(NODE_DATA(nid), usemap_size());
+        if (usemap)
+                return usemap;
+
+        /* Stupid: suppress gcc warning for SPARSEMEM && !NUMA */
+        nid = 0;
+
+        printk(KERN_WARNING "%s: allocation failed\n", __FUNCTION__);
+        return NULL;
+}
+
 #ifndef CONFIG_SPARSEMEM_VMEMMAP
 struct page __init *sparse_early_mem_map_populate(unsigned long pnum, int nid)
 {
@@ -268,6 +302,7 @@ void __init sparse_init(void)
 {
         unsigned long pnum;
         struct page *map;
+        unsigned long *usemap;
 
         for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
                 if (!present_section_nr(pnum))
@@ -276,7 +311,13 @@ void __init sparse_init(void)
                 map = sparse_early_mem_map_alloc(pnum);
                 if (!map)
                         continue;
-                sparse_init_one_section(__nr_to_section(pnum), pnum, map);
+
+                usemap = sparse_early_usemap_alloc(pnum);
+                if (!usemap)
+                        continue;
+
+                sparse_init_one_section(__nr_to_section(pnum), pnum, map,
+                                                                usemap);
         }
 }
 
@@ -332,6 +373,7 @@ int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
         struct pglist_data *pgdat = zone->zone_pgdat;
         struct mem_section *ms;
         struct page *memmap;
+        unsigned long *usemap;
         unsigned long flags;
         int ret;
 
@@ -341,6 +383,7 @@ int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
          */
         sparse_index_init(section_nr, pgdat->node_id);
         memmap = __kmalloc_section_memmap(nr_pages);
+        usemap = __kmalloc_section_usemap();
 
         pgdat_resize_lock(pgdat, &flags);
 
@@ -349,9 +392,14 @@ int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
                 ret = -EEXIST;
                 goto out;
         }
+
+        if (!usemap) {
+                ret = -ENOMEM;
+                goto out;
+        }
         ms->section_mem_map |= SECTION_MARKED_PRESENT;
 
-        ret = sparse_init_one_section(ms, section_nr, memmap);
+        ret = sparse_init_one_section(ms, section_nr, memmap, usemap);
 
 out:
         pgdat_resize_unlock(pgdat, &flags);