1 files changed, 11 insertions, 6 deletions

diff --git a/mm/sparse.c b/mm/sparse.c
index 4900707ae146..044138852baf 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -23,8 +23,7 @@
  * 1) mem_section       - memory sections, mem_map's for valid memory
  */
 #ifdef CONFIG_SPARSEMEM_EXTREME
-struct mem_section *mem_section[NR_SECTION_ROOTS]
-        ____cacheline_internodealigned_in_smp;
+struct mem_section **mem_section;
 #else
 struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
         ____cacheline_internodealigned_in_smp;
@@ -101,7 +100,7 @@ static inline int sparse_index_init(unsigned long section_nr, int nid)
 int __section_nr(struct mem_section* ms)
 {
         unsigned long root_nr;
-        struct mem_section* root;
+        struct mem_section *root = NULL;
 
         for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
                 root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
@@ -112,7 +111,7 @@ int __section_nr(struct mem_section* ms)
                      break;
         }
 
-        VM_BUG_ON(root_nr == NR_SECTION_ROOTS);
+        VM_BUG_ON(!root);
 
         return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
 }
@@ -330,11 +329,17 @@ again:
 static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
 {
         unsigned long usemap_snr, pgdat_snr;
-        static unsigned long old_usemap_snr = NR_MEM_SECTIONS;
-        static unsigned long old_pgdat_snr = NR_MEM_SECTIONS;
+        static unsigned long old_usemap_snr;
+        static unsigned long old_pgdat_snr;
         struct pglist_data *pgdat = NODE_DATA(nid);
         int usemap_nid;
 
+        /* First call */
+        if (!old_usemap_snr) {
+                old_usemap_snr = NR_MEM_SECTIONS;
+                old_pgdat_snr = NR_MEM_SECTIONS;
+        }
+
         usemap_snr = pfn_to_section_nr(__pa(usemap) >> PAGE_SHIFT);
         pgdat_snr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT);
         if (usemap_snr == pgdat_snr)