From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751903AbYIEKUx (ORCPT ); Fri, 5 Sep 2008 06:20:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751776AbYIEKUO (ORCPT ); Fri, 5 Sep 2008 06:20:14 -0400 Received: from tallyho.bytemark.co.uk ([80.68.81.166]:41337 "EHLO tallyho.bytemark.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751643AbYIEKUL (ORCPT ); Fri, 5 Sep 2008 06:20:11 -0400 From: Andy Whitcroft To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, KOSAKI Motohiro , Peter Zijlstra , Christoph Lameter , Rik van Riel , Mel Gorman , Andy Whitcroft Subject: [PATCH 1/4] pull out the page pre-release and sanity check logic for reuse Date: Fri, 5 Sep 2008 11:19:59 +0100 Message-Id: <1220610002-18415-2-git-send-email-apw@shadowen.org> X-Mailer: git-send-email 1.6.0.rc1.258.g80295 In-Reply-To: <1220610002-18415-1-git-send-email-apw@shadowen.org> References: <1220610002-18415-1-git-send-email-apw@shadowen.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When we are about to release a page we perform a number of actions on that page. We clear down any anonymous mappings, confirm that the page is safe to release, check for freeing locks, before mapping the page should that be required. Pull this processing out into a helper function for reuse in a later patch. Note that we do not convert the similar cleardown in free_hot_cold_page() as the optimiser is unable to squash the loops during the inline. Signed-off-by: Andy Whitcroft Acked-by: Peter Zijlstra Acked-by: KOSAKI Motohiro Reviewed-by: Rik van Riel --- mm/page_alloc.c | 43 ++++++++++++++++++++++++++++++------------- 1 files changed, 30 insertions(+), 13 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index f52fcf1..b2a2c2b 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -489,6 +489,35 @@ static inline int free_pages_check(struct page *page) } /* + * Prepare this page for release to the buddy. Sanity check the page. + * Returns 1 if the page is safe to free. + */ +static inline int free_page_prepare(struct page *page, int order) +{ + int i; + int reserved = 0; + + if (PageAnon(page)) + page->mapping = NULL; + + for (i = 0 ; i < (1 << order) ; ++i) + reserved += free_pages_check(page + i); + if (reserved) + return 0; + + if (!PageHighMem(page)) { + debug_check_no_locks_freed(page_address(page), + PAGE_SIZE << order); + debug_check_no_obj_freed(page_address(page), + PAGE_SIZE << order); + } + arch_free_page(page, order); + kernel_map_pages(page, 1 << order, 0); + + return 1; +} + +/* * Frees a list of pages. * Assumes all pages on list are in same zone, and of same order. * count is the number of pages to free. @@ -529,22 +558,10 @@ static void free_one_page(struct zone *zone, struct page *page, int order) static void __free_pages_ok(struct page *page, unsigned int order) { unsigned long flags; - int i; - int reserved = 0; - for (i = 0 ; i < (1 << order) ; ++i) - reserved += free_pages_check(page + i); - if (reserved) + if (!free_page_prepare(page, order)) return; - if (!PageHighMem(page)) { - debug_check_no_locks_freed(page_address(page),PAGE_SIZE<