Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932148AbbB0DhX (ORCPT ); Thu, 26 Feb 2015 22:37:23 -0500 Received: from cnbjrel02.sonyericsson.com ([219.141.167.166]:12831 "EHLO cnbjrel02.sonyericsson.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932089AbbB0DhW convert rfc822-to-8bit (ORCPT ); Thu, 26 Feb 2015 22:37:22 -0500 From: "Wang, Yalin" To: "'Minchan Kim'" , Michal Hocko , Andrew Morton , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Rik van Riel , Johannes Weiner , Mel Gorman , Shaohua Li Date: Fri, 27 Feb 2015 11:37:18 +0800 Subject: [RFC] mm: change mm_advise_free to clear page dirty Thread-Topic: [RFC] mm: change mm_advise_free to clear page dirty Thread-Index: AdBQjy3AwY3Rx4ZYTWqPB5c9r68pMQBryeTQ Message-ID: <35FD53F367049845BC99AC72306C23D10458D6173BDC@CNBJMBX05.corpusers.net> References: <1424765897-27377-1-git-send-email-minchan@kernel.org> <20150224154318.GA14939@dhcp22.suse.cz> <20150225000809.GA6468@blaptop> In-Reply-To: <20150225000809.GA6468@blaptop> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1463 Lines: 50 This patch add ClearPageDirty() to clear AnonPage dirty flag, the Anonpage mapcount must be 1, so that this page is only used by the current process, not shared by other process like fork(). if not clear page dirty for this anon page, the page will never be treated as freeable. Signed-off-by: Yalin Wang --- mm/madvise.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index 6d0fcb8..257925a 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -297,22 +297,17 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, continue; page = vm_normal_page(vma, addr, ptent); - if (!page) + if (!page || !PageAnon(page) || !trylock_page(page)) continue; if (PageSwapCache(page)) { - if (!trylock_page(page)) + if (!try_to_free_swap(page)) continue; - - if (!try_to_free_swap(page)) { - unlock_page(page); - continue; - } - - ClearPageDirty(page); - unlock_page(page); } + if (page_mapcount(page) == 1) + ClearPageDirty(page); + unlock_page(page); /* * Some of architecture(ex, PPC) don't update TLB * with set_pte_at and tlb_remove_tlb_entry so for -- 2.2.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/