From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35137C3A59C for ; Thu, 15 Aug 2019 17:19:24 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 01DF2205F4 for ; Thu, 15 Aug 2019 17:19:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 01DF2205F4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 95D186B02E2; Thu, 15 Aug 2019 13:19:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 90CCB6B02E4; Thu, 15 Aug 2019 13:19:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8226B6B02E5; Thu, 15 Aug 2019 13:19:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0245.hostedemail.com [216.40.44.245]) by kanga.kvack.org (Postfix) with ESMTP id 613EB6B02E2 for ; Thu, 15 Aug 2019 13:19:23 -0400 (EDT) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id 1FE4F8248AB8 for ; Thu, 15 Aug 2019 17:19:23 +0000 (UTC) X-FDA: 75825323406.08.plant16_51d7a2a40a832 X-HE-Tag: plant16_51d7a2a40a832 X-Filterd-Recvd-Size: 3842 Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by imf37.hostedemail.com (Postfix) with ESMTP for ; Thu, 15 Aug 2019 17:19:22 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 41DFE8535C; Thu, 15 Aug 2019 17:19:21 +0000 (UTC) Received: from redhat.com (unknown [10.20.6.178]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 24D02601A4; Thu, 15 Aug 2019 17:19:20 +0000 (UTC) Date: Thu, 15 Aug 2019 13:19:18 -0400 From: Jerome Glisse To: Pingfan Liu Cc: linux-mm@kvack.org, Andrew Morton , Mel Gorman , Jan Kara , "Kirill A. Shutemov" , Michal Hocko , Mike Kravetz , Andrea Arcangeli , Matthew Wilcox , linux-kernel@vger.kernel.org Subject: Re: [PATCHv2] mm/migrate: clean up useless code in migrate_vma_collect_pmd() Message-ID: <20190815171918.GC30916@redhat.com> References: <20190807052858.GA9749@mypc> <1565167272-21453-1-git-send-email-kernelfans@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <1565167272-21453-1-git-send-email-kernelfans@gmail.com> User-Agent: Mutt/1.11.3 (2019-02-01) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Thu, 15 Aug 2019 17:19:21 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Aug 07, 2019 at 04:41:12PM +0800, Pingfan Liu wrote: > Clean up useless 'pfn' variable. NAK there is a bug see below: >=20 > Signed-off-by: Pingfan Liu > Cc: "J=E9r=F4me Glisse" > Cc: Andrew Morton > Cc: Mel Gorman > Cc: Jan Kara > Cc: "Kirill A. Shutemov" > Cc: Michal Hocko > Cc: Mike Kravetz > Cc: Andrea Arcangeli > Cc: Matthew Wilcox > To: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > --- > mm/migrate.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) >=20 > diff --git a/mm/migrate.c b/mm/migrate.c > index 8992741..d483a55 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -2225,17 +2225,15 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp, > pte_t pte; > =20 > pte =3D *ptep; > - pfn =3D pte_pfn(pte); > =20 > if (pte_none(pte)) { > mpfn =3D MIGRATE_PFN_MIGRATE; > migrate->cpages++; > - pfn =3D 0; > goto next; > } > =20 > if (!pte_present(pte)) { > - mpfn =3D pfn =3D 0; > + mpfn =3D 0; > =20 > /* > * Only care about unaddressable device page special > @@ -2252,10 +2250,10 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp, > if (is_write_device_private_entry(entry)) > mpfn |=3D MIGRATE_PFN_WRITE; > } else { > + pfn =3D pte_pfn(pte); > if (is_zero_pfn(pfn)) { > mpfn =3D MIGRATE_PFN_MIGRATE; > migrate->cpages++; > - pfn =3D 0; > goto next; > } > page =3D vm_normal_page(migrate->vma, addr, pte); > @@ -2265,10 +2263,9 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp, > =20 > /* FIXME support THP */ > if (!page || !page->mapping || PageTransCompound(page)) { > - mpfn =3D pfn =3D 0; > + mpfn =3D 0; > goto next; > } > - pfn =3D page_to_pfn(page); You can not remove that one ! Otherwise it will break the device private case.