From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762942AbZEHLPY (ORCPT ); Fri, 8 May 2009 07:15:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759932AbZEHLMx (ORCPT ); Fri, 8 May 2009 07:12:53 -0400 Received: from mga03.intel.com ([143.182.124.21]:43371 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759456AbZEHLMt (ORCPT ); Fri, 8 May 2009 07:12:49 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.40,316,1239001200"; d="scan'208";a="140664202" Message-Id: <20090508111030.264063904@intel.com> References: <20090508105320.316173813@intel.com> User-Agent: quilt/0.46-1 Date: Fri, 08 May 2009 18:53:21 +0800 From: Wu Fengguang To: Andrew Morton Cc: LKML , Wu Fengguang Cc: Matt Mackall Cc: KOSAKI Motohiro CC: Andi Kleen , Subject: [PATCH 1/8] mm: introduce PageHuge() for testing huge/gigantic pages Content-Disposition: inline; filename=giga-page.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Introduce PageHuge(), which identifies huge/gigantic pages by their dedicated compound destructor functions. Signed-off-by: Wu Fengguang --- include/linux/mm.h | 24 ++++++++++++++++++++++++ mm/hugetlb.c | 2 +- mm/page_alloc.c | 11 ++++++++++- 3 files changed, 35 insertions(+), 2 deletions(-) --- linux.orig/mm/page_alloc.c +++ linux/mm/page_alloc.c @@ -299,13 +299,22 @@ void prep_compound_page(struct page *pag } #ifdef CONFIG_HUGETLBFS +/* + * This (duplicated) destructor function distinguishes gigantic pages from + * normal compound pages. + */ +void free_gigantic_page(struct page *page) +{ + __free_pages_ok(page, compound_order(page)); +} + void prep_compound_gigantic_page(struct page *page, unsigned long order) { int i; int nr_pages = 1 << order; struct page *p = page + 1; - set_compound_page_dtor(page, free_compound_page); + set_compound_page_dtor(page, free_gigantic_page); set_compound_order(page, order); __SetPageHead(page); for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { --- linux.orig/mm/hugetlb.c +++ linux/mm/hugetlb.c @@ -550,7 +550,7 @@ struct hstate *size_to_hstate(unsigned l return NULL; } -static void free_huge_page(struct page *page) +void free_huge_page(struct page *page) { /* * Can't pass hstate in here because it is called from the --- linux.orig/include/linux/mm.h +++ linux/include/linux/mm.h @@ -355,6 +355,30 @@ static inline void set_compound_order(st page[1].lru.prev = (void *)order; } +#ifdef CONFIG_HUGETLBFS +void free_huge_page(struct page *page); +void free_gigantic_page(struct page *page); + +static inline int PageHuge(struct page *page) +{ + compound_page_dtor *dtor; + + if (!PageCompound(page)) + return 0; + + page = compound_head(page); + dtor = get_compound_page_dtor(page); + + return dtor == free_huge_page || + dtor == free_gigantic_page; +} +#else +static inline int PageHuge(struct page *page) +{ + return 0; +} +#endif + /* * Multiple processes may "see" the same page. E.g. for untouched * mappings of /dev/null, all processes see the same page full of --