mm/hugetlb: clear compound_mapcount when freeing gigantic pages

[cascardo/linux.git] / mm / hugetlb.c

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 388c2bb..c1f3c0b 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1030,6 +1030,7 @@ static void destroy_compound_gigantic_page(struct page *page,
        int nr_pages = 1 << order;
        struct page *p = page + 1;
 
+       atomic_set(compound_mapcount_ptr(page), 0);
        for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
                clear_compound_head(p);
                set_page_refcounted(p);
@@ -4228,7 +4229,6 @@ pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
                if (saddr) {
                        spte = huge_pte_offset(svma->vm_mm, saddr);
                        if (spte) {
-                               mm_inc_nr_pmds(mm);
                                get_page(virt_to_page(spte));
                                break;
                        }
@@ -4243,9 +4243,9 @@ pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
        if (pud_none(*pud)) {
                pud_populate(mm, pud,
                                (pmd_t *)((unsigned long)spte & PAGE_MASK));
+               mm_inc_nr_pmds(mm);
        } else {
                put_page(virt_to_page(spte));
-               mm_inc_nr_pmds(mm);
        }
        spin_unlock(ptl);
 out: