hugetlb: redefine hugepage copy functions

This patch modifies hugepage copy functions to have only destination
and source hugepages as arguments for later use.
The old ones are renamed from copy_{gigantic,huge}_page() to
copy_user_{gigantic,huge}_page().
This naming convention is consistent with that between copy_highpage()
and copy_user_highpage().

ChangeLog since v4:
- add blank line between local declaration and code
- remove unnecessary might_sleep()

ChangeLog since v2:
- change copy_huge_page() from macro to inline dummy function
  to avoid compile warning when !CONFIG_HUGETLB_PAGE.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

1 files changed, 40 insertions, 5 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 83fa0c3b6e2b..a73dbdcb89eb 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -423,14 +423,14 @@ static void clear_huge_page(struct page *page,
         }
 }
 
-static void copy_gigantic_page(struct page *dst, struct page *src,
+static void copy_user_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);
@@ -440,14 +440,15 @@ static void copy_gigantic_page(struct page *dst, struct page *src,
                 src = mem_map_next(src, src_base, i);
         }
 }
-static void copy_huge_page(struct page *dst, struct page *src,
+
+static void copy_user_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)) {
-                copy_gigantic_page(dst, src, addr, vma);
+                copy_user_gigantic_page(dst, src, addr, vma);
                 return;
         }
 
@@ -458,6 +459,40 @@ static void copy_huge_page(struct page *dst, struct page *src,
         }
 }
 
+static void copy_gigantic_page(struct page *dst, struct page *src)
+{
+        int i;
+        struct hstate *h = page_hstate(src);
+        struct page *dst_base = dst;
+        struct page *src_base = src;
+
+        for (i = 0; i < pages_per_huge_page(h); ) {
+                cond_resched();
+                copy_highpage(dst, src);
+
+                i++;
+                dst = mem_map_next(dst, dst_base, i);
+                src = mem_map_next(src, src_base, i);
+        }
+}
+
+void copy_huge_page(struct page *dst, struct page *src)
+{
+        int i;
+        struct hstate *h = page_hstate(src);
+
+        if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) {
+                copy_gigantic_page(dst, src);
+                return;
+        }
+
+        might_sleep();
+        for (i = 0; i < pages_per_huge_page(h); i++) {
+                cond_resched();
+                copy_highpage(dst + i, src + i);
+        }
+}
+
 static void enqueue_huge_page(struct hstate *h, struct page *page)
 {
         int nid = page_to_nid(page);
@@ -2412,7 +2447,7 @@ retry_avoidcopy:
         if (unlikely(anon_vma_prepare(vma)))
                 return VM_FAULT_OOM;
 
-        copy_huge_page(new_page, old_page, address, vma);
+        copy_user_huge_page(new_page, old_page, address, vma);
         __SetPageUptodate(new_page);
 
         /*