mm, hugetlb: do not use a page in page cache for cow optimization

[mirror_ubuntu-zesty-kernel.git] / mm / hugetlb.c

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index a13be48b818becf82f5f27df2add172f37c23301..da027a3307af000d757f759f50d3ee706f9be391 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2528,7 +2528,6 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
 {
        struct hstate *h = hstate_vma(vma);
        struct page *old_page, *new_page;
-       int avoidcopy;
        int outside_reserve = 0;
        unsigned long mmun_start;       /* For mmu_notifiers */
        unsigned long mmun_end;         /* For mmu_notifiers */
@@ -2538,10 +2537,8 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
 retry_avoidcopy:
        /* If no-one else is actually using this page, avoid the copy
         * and just make the page writable */
-       avoidcopy = (page_mapcount(old_page) == 1);
-       if (avoidcopy) {
-               if (PageAnon(old_page))
-                       page_move_anon_rmap(old_page, vma, address);
+       if (page_mapcount(old_page) == 1 && PageAnon(old_page)) {
+               page_move_anon_rmap(old_page, vma, address);
                set_huge_ptep_writable(vma, address, ptep);
                return 0;
        }