1 files changed, 10 insertions, 0 deletions

diff --git a/mm/sparse.c b/mm/sparse.c
index b00a97398795..d294148ba395 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -206,6 +206,16 @@ void __init memory_present(int nid, unsigned long start, unsigned long end)
 {
         unsigned long pfn;
 
+#ifdef CONFIG_SPARSEMEM_EXTREME
+        if (unlikely(!mem_section)) {
+                unsigned long size, align;
+
+                size = sizeof(struct mem_section) * NR_SECTION_ROOTS;
+                align = 1 << (INTERNODE_CACHE_SHIFT);
+                mem_section = memblock_virt_alloc(size, align);
+        }
+#endif
+
         start &= PAGE_SECTION_MASK;
         mminit_validate_memmodel_limits(&start, &end);
         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {