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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS 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 7E704C43441 for ; Wed, 21 Nov 2018 04:51:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3D5CC21104 for ; Wed, 21 Nov 2018 04:51:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="KYUv/rCE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3D5CC21104 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727206AbeKUPYq (ORCPT ); Wed, 21 Nov 2018 10:24:46 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:34580 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726049AbeKUPYp (ORCPT ); Wed, 21 Nov 2018 10:24:45 -0500 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.22/8.16.0.22) with SMTP id wAL4nMqs032244; Wed, 21 Nov 2018 04:51:49 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=content-type : mime-version : subject : from : in-reply-to : date : cc : content-transfer-encoding : message-id : references : to; s=corp-2018-07-02; bh=ObcDvYuCvCRY854lGNth8zzfyqEUvVBRMF/Qt74EXuE=; b=KYUv/rCE/lT+oc+6eV3gucNcZHOeI3d0yFGKUrSOtHxcLZGq+9ibWqZ19it0q2hXyPkD qd0fA2rAKTW2dDpijvMP3FEq5JiZA81qH+niJCYoY+DONuchuL3K8rZ5YM1eXtaWgS9X p8ACNP4Q+GghzoQgRIwtQyaZ5FkNvsRtUXMdL5VYqL2P7JZl7qP3xsCsqCcj/U3fPZrE fhgDzaEKCnxzwJkEcUJjEZQR5LCHQx2mwMnCRy4aIfkggDwbcZTkm0hg/o6r+ubeKtEb luHD6oacE2q10FNMFfg6QkbF4LdOr9tsi8tyKEGVkmg8qvSZgbxliFq5omN0Ek+RRjUP VA== Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by userp2130.oracle.com with ESMTP id 2ntadtydgj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 21 Nov 2018 04:51:49 +0000 Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id wAL4pg56026719 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 21 Nov 2018 04:51:43 GMT Received: from abhmp0013.oracle.com (abhmp0013.oracle.com [141.146.116.19]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id wAL4pf8x018611; Wed, 21 Nov 2018 04:51:41 GMT Received: from [192.168.0.110] (/73.243.10.6) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 20 Nov 2018 20:51:40 -0800 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 12.2 \(3445.102.3\)) Subject: Re: [RFC PATCH 3/3] mm, fault_around: do not take a reference to a locked page From: William Kucharski In-Reply-To: <20181120141207.GK22247@dhcp22.suse.cz> Date: Tue, 20 Nov 2018 21:51:39 -0700 Cc: "Kirill A. Shutemov" , Linux-MM , Andrew Morton , Oscar Salvador , Pavel Tatashin , David Hildenbrand , LKML Content-Transfer-Encoding: 7bit Message-Id: <29F15A96-D6EB-450E-B54B-A4CB460ED9B3@oracle.com> References: <20181120134323.13007-1-mhocko@kernel.org> <20181120134323.13007-4-mhocko@kernel.org> <20181120140715.mouc7okin3ht5krr@kshutemo-mobl1> <20181120141207.GK22247@dhcp22.suse.cz> To: Michal Hocko X-Mailer: Apple Mail (2.3445.102.3) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9083 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=663 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1811210044 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Nov 20, 2018, at 7:12 AM, Michal Hocko wrote: > > + /* > + * Check the locked pages before taking a reference to not > + * go in the way of migration. > + */ Could you make this a tiny bit more explanative, something like: + /* + * Check for a locked page first, as a speculative + * reference may adversely influence page migration. + */ Reviewed-by: William Kucharski