1 files changed, 47 insertions, 2 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 421aee9..d143ab6 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -354,11 +354,26 @@ static int vma_has_reserves(struct vm_area_struct *vma)
 	return 0;
 }
 
+static void clear_gigantic_page(struct page *page,
+			unsigned long addr, unsigned long sz)
+{
+	int i;
+	struct page *p = page;
+
+	might_sleep();
+	for (i = 0; i < sz/PAGE_SIZE; i++, p = mem_map_next(p, page, i)) {
+		cond_resched();
+		clear_user_highpage(p, addr + i * PAGE_SIZE);
+	}
+}
 static void clear_huge_page(struct page *page,
 			unsigned long addr, unsigned long sz)
 {
 	int i;
 
+	if (unlikely(sz > MAX_ORDER_NR_PAGES))
+		return clear_gigantic_page(page, addr, sz);
+
 	might_sleep();
 	for (i = 0; i < sz/PAGE_SIZE; i++) {
 		cond_resched();
@@ -366,12 +381,32 @@ static void clear_huge_page(struct page *page,
 	}
 }
 
+static void copy_gigantic_page(struct page *dst, struct page *src,
+			   unsigned long addr, struct vm_area_struct *vma)
+{
+	int i;
+	struct hstate *h = hstate_vma(vma);
+	struct page *dst_base = dst;
+	struct page *src_base = src;
+	might_sleep();
+	for (i = 0; i < pages_per_huge_page(h); ) {
+		cond_resched();
+		copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma);
+
+		i++;
+		dst = mem_map_next(dst, dst_base, i);
+		src = mem_map_next(src, src_base, i);
+	}
+}
 static void copy_huge_page(struct page *dst, struct page *src,
 			   unsigned long addr, struct vm_area_struct *vma)
 {
 	int i;
 	struct hstate *h = hstate_vma(vma);
 
+	if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES))
+		return copy_gigantic_page(dst, src, addr, vma);
+
 	might_sleep();
 	for (i = 0; i < pages_per_huge_page(h); i++) {
 		cond_resched();
@@ -456,6 +491,8 @@ static void update_and_free_page(struct hstate *h, struct page *page)
 {
 	int i;
 
+	VM_BUG_ON(h->order >= MAX_ORDER);
+
 	h->nr_huge_pages--;
 	h->nr_huge_pages_node[page_to_nid(page)]--;
 	for (i = 0; i < pages_per_huge_page(h); i++) {
@@ -970,6 +1007,14 @@ found:
 	return 1;
 }
 
+static void prep_compound_huge_page(struct page *page, int order)
+{
+	if (unlikely(order > (MAX_ORDER - 1)))
+		prep_compound_gigantic_page(page, order);
+	else
+		prep_compound_page(page, order);
+}
+
 /* Put bootmem huge pages into the standard lists after mem_map is up */
 static void __init gather_bootmem_prealloc(void)
 {
@@ -980,7 +1025,7 @@ static void __init gather_bootmem_prealloc(void)
 		struct hstate *h = m->hstate;
 		__ClearPageReserved(page);
 		WARN_ON(page_count(page) != 1);
-		prep_compound_page(page, h->order);
+		prep_compound_huge_page(page, h->order);
 		prep_new_huge_page(h, page, page_to_nid(page));
 	}
 }
@@ -2130,7 +2175,7 @@ same_page:
 			if (zeropage_ok)
 				pages[i] = ZERO_PAGE(0);
 			else
-				pages[i] = page + pfn_offset;
+				pages[i] = mem_map_offset(page, pfn_offset);
 			get_page(pages[i]);
 		}