diff options
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index dde04ff4be31..eec89ab39bb6 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++) { |