Per the void prep_compound_page(struct page *page, unsigned long order) code, compound pages use PG_head/PG_tail, and only tail pages point at head page using their ->first_page field. Signed-off-by: Wang Sheng-Hui <shhuiw@xxxxxxxxx> --- mm/page_alloc.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6e8ecb6..f645ce8 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -332,8 +332,8 @@ out: * * The remaining PAGE_SIZE pages are called "tail pages". * - * All pages have PG_compound set. All pages have their ->private pointing at - * the head page (even the head page has this). + * Head page has PG_head set, and all tail pages have PG_tail set. All tail + * pages have their ->first_page pointing at the head page. * * 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. -- 1.7.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>