Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751947AbaKYDCU (ORCPT ); Mon, 24 Nov 2014 22:02:20 -0500 Received: from TYO201.gate.nec.co.jp ([210.143.35.51]:59908 "EHLO tyo201.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750770AbaKYDCT convert rfc822-to-8bit (ORCPT ); Mon, 24 Nov 2014 22:02:19 -0500 From: Naoya Horiguchi To: "Kirill A. Shutemov" CC: Andrew Morton , Andrea Arcangeli , Dave Hansen , Hugh Dickins , Mel Gorman , Rik van Riel , Vlastimil Babka , Christoph Lameter , Steve Capper , "Aneesh Kumar K.V" , Johannes Weiner , Michal Hocko , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" Subject: Re: [PATCH 01/19] mm, thp: drop FOLL_SPLIT Thread-Topic: [PATCH 01/19] mm, thp: drop FOLL_SPLIT Thread-Index: AQHP+QfSWbFOdr5ZS0iDGj9k1RQfn5xwLzCA Date: Tue, 25 Nov 2014 03:01:16 +0000 Message-ID: <20141125030109.GA21716@hori1.linux.bs1.fc.nec.co.jp> References: <1415198994-15252-1-git-send-email-kirill.shutemov@linux.intel.com> <1415198994-15252-2-git-send-email-kirill.shutemov@linux.intel.com> In-Reply-To: <1415198994-15252-2-git-send-email-kirill.shutemov@linux.intel.com> Accept-Language: ja-JP, en-US Content-Language: ja-JP X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.128.101.12] Content-Type: text/plain; charset="iso-2022-jp" Content-ID: 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 On Wed, Nov 05, 2014 at 04:49:36PM +0200, Kirill A. Shutemov wrote: > FOLL_SPLIT is used only in two places: migration and s390. > > Let's replace it with explicit split and remove FOLL_SPLIT. > > Signed-off-by: Kirill A. Shutemov > --- ... > @@ -1246,6 +1246,11 @@ static int do_move_page_to_node_array(struct mm_struct *mm, > if (!page) > goto set_status; > > + if (PageTransHuge(page) && split_huge_page(page)) { > + err = -EBUSY; > + goto set_status; > + } > + This check makes split_huge_page() be called for hugetlb pages, which triggers BUG_ON. So could you do this after if (PageHuge) block below? And I think that we have "Node already in the right place" check afterward, so I hope that moving down this check also helps us reduce thp splitting. Thanks, Naoya Horiguchi > /* Use PageReserved to check for zero page */ > if (PageReserved(page)) > goto put_and_set;-- 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/