diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 67f29516662..508707704d2 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -85,7 +85,7 @@ void free_huge_page(struct page *page) BUG_ON(page_count(page)); INIT_LIST_HEAD(&page->lru); - page[1].mapping = NULL; + page[1].lru.next = NULL; /* reset dtor */ spin_lock(&hugetlb_lock); enqueue_huge_page(page); @@ -105,7 +105,7 @@ struct page *alloc_huge_page(struct vm_area_struct *vma, unsigned long addr) } spin_unlock(&hugetlb_lock); set_page_count(page, 1); - page[1].mapping = (void *)free_huge_page; + page[1].lru.next = (void *)free_huge_page; /* set dtor */ for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); ++i) clear_user_highpage(&page[i], addr); return page; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index dde04ff4be3..eec89ab39bb 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -169,20 +169,17 @@ static void bad_page(struct page *page) * All pages have PG_compound set. All pages have their ->private pointing at * the head page (even the head page has this). * - * The first tail page's ->mapping, if non-zero, holds the address of the - * compound page's put_page() function. - * - * The order of the allocation is stored in the first tail page's ->index - * This is only for debug at present. This usage means that zero-order pages - * may not be compound. + * The first tail page's ->lru.next holds the address of the compound page's + * put_page() function. Its ->lru.prev holds the order of allocation. + * This usage means that zero-order pages may not be compound. */ static void prep_compound_page(struct page *page, unsigned long order) { int i; int nr_pages = 1 << order; - page[1].mapping = NULL; - page[1].index = order; + page[1].lru.next = NULL; /* set dtor */ + page[1].lru.prev = (void *)order; for (i = 0; i < nr_pages; i++) { struct page *p = page + i; @@ -196,7 +193,7 @@ static void destroy_compound_page(struct page *page, unsigned long order) int i; int nr_pages = 1 << order; - if (unlikely(page[1].index != order)) + if (unlikely((unsigned long)page[1].lru.prev != order)) bad_page(page); for (i = 0; i < nr_pages; i++) { diff --git a/mm/swap.c b/mm/swap.c index 76247424dea..cce3dda59c5 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -40,7 +40,7 @@ static void put_compound_page(struct page *page) if (put_page_testzero(page)) { void (*dtor)(struct page *page); - dtor = (void (*)(struct page *))page[1].mapping; + dtor = (void (*)(struct page *))page[1].lru.next; (*dtor)(page); } }