From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753333Ab1KOIG3 (ORCPT ); Tue, 15 Nov 2011 03:06:29 -0500 Received: from mail-yw0-f46.google.com ([209.85.213.46]:52987 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751591Ab1KOIG2 (ORCPT ); Tue, 15 Nov 2011 03:06:28 -0500 Message-ID: <4EC21D78.4080508@gmail.com> Date: Tue, 15 Nov 2011 16:06:16 +0800 From: Wang Sheng-Hui User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.18) Gecko/20110617 Thunderbird/3.1.11 MIME-Version: 1.0 To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] mm: cleanup the comment for head/tail pages of compound pages in mm/page_alloc.c Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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