From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752809AbbIOK3a (ORCPT ); Tue, 15 Sep 2015 06:29:30 -0400 Received: from mga03.intel.com ([134.134.136.65]:20468 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751640AbbIOK3Z (ORCPT ); Tue, 15 Sep 2015 06:29:25 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,535,1437462000"; d="scan'208";a="805481607" From: "Kirill A. Shutemov" To: Andrew Morton , Hugh Dickins Cc: Andrea Arcangeli , Dave Hansen , Vlastimil Babka , Johannes Weiner , Michal Hocko , David Rientjes , "Aneesh Kumar K.V" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A. Shutemov" Subject: [PATCHv6 3/7] zsmalloc: use page->private instead of page->first_page Date: Tue, 15 Sep 2015 13:28:11 +0300 Message-Id: <1442312895-124384-4-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.5.1 In-Reply-To: <1442312895-124384-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1442312895-124384-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We are going to rework how compound_head() work. It will not use page->first_page as we have it now. The only other user of page->first_page beyond compound pages is zsmalloc. Let's use page->private instead of page->first_page here. It occupies the same storage space. Signed-off-by: Kirill A. Shutemov Acked-by: Vlastimil Babka Reviewed-by: Sergey Senozhatsky Reviewed-by: Andrea Arcangeli --- mm/zsmalloc.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index f135b1b6fcdc..14fc466785da 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -16,7 +16,7 @@ * struct page(s) to form a zspage. * * Usage of struct page fields: - * page->first_page: points to the first component (0-order) page + * page->private: points to the first component (0-order) page * page->index (union with page->freelist): offset of the first object * starting in this page. For the first page, this is * always 0, so we use this field (aka freelist) to point @@ -26,8 +26,7 @@ * * For _first_ page only: * - * page->private (union with page->first_page): refers to the - * component page after the first page + * page->private: refers to the component page after the first page * If the page is first_page for huge object, it stores handle. * Look at size_class->huge. * page->freelist: points to the first free object in zspage. @@ -764,7 +763,7 @@ static struct page *get_first_page(struct page *page) if (is_first_page(page)) return page; else - return page->first_page; + return (struct page *)page_private(page); } static struct page *get_next_page(struct page *page) @@ -949,7 +948,7 @@ static struct page *alloc_zspage(struct size_class *class, gfp_t flags) * Allocate individual pages and link them together as: * 1. first page->private = first sub-page * 2. all sub-pages are linked together using page->lru - * 3. each sub-page is linked to the first page using page->first_page + * 3. each sub-page is linked to the first page using page->private * * For each size class, First/Head pages are linked together using * page->lru. Also, we set PG_private to identify the first page @@ -974,7 +973,7 @@ static struct page *alloc_zspage(struct size_class *class, gfp_t flags) if (i == 1) set_page_private(first_page, (unsigned long)page); if (i >= 1) - page->first_page = first_page; + set_page_private(page, (unsigned long)first_page); if (i >= 2) list_add(&page->lru, &prev_page->lru); if (i == class->pages_per_zspage - 1) /* last page */ -- 2.5.1