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=-6.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 A0801C433E7 for ; Thu, 15 Oct 2020 21:21:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 292952076A for ; Thu, 15 Oct 2020 21:21:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="UdL45CHP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729804AbgJOVVM (ORCPT ); Thu, 15 Oct 2020 17:21:12 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:37264 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729788AbgJOVVL (ORCPT ); Thu, 15 Oct 2020 17:21:11 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 09FL9sgf108414; Thu, 15 Oct 2020 21:20:52 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2020-01-29; bh=FV6I0fsZyPX8snT2xhDk1zWcNw8UiciM8erCRzN6Udo=; b=UdL45CHPPOXDZ4zEFtc3Q/95eR77q0866gQGri1DzwdjlNd24SbdmOlguedwVWaTTCN0 MFQLMyYBoEpoE32Drz7s/kHLIoSt1DAy53Sn7DnIkdoPt6ZEafnvjo7uGev5InylXvu+ 3fkUWycsHofjpjERriR4m1C01w7P3fjrPyQ2bax2nLFmFXXcBWHJDxH46R/E0FWWIEg0 a4DIWx9TkQ2mFI7zZAdLHqnVbUIrhViQRFaMyGrxo9btO2b5wWI5PN/0GKOeJ7HdAVRG VgB562Dhgvt5zkRkwh78wE9mkvCxQ36uaSIfDy2T6FKagxGTQbx7zNWUbaWVfroDV8N5 WQ== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2120.oracle.com with ESMTP id 343vaencsn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 15 Oct 2020 21:20:52 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 09FLBMm9119076; Thu, 15 Oct 2020 21:20:51 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserp3020.oracle.com with ESMTP id 343pv2bq13-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 15 Oct 2020 21:20:51 +0000 Received: from abhmp0015.oracle.com (abhmp0015.oracle.com [141.146.116.21]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 09FLKdb5010307; Thu, 15 Oct 2020 21:20:39 GMT Received: from [192.168.0.108] (/70.36.60.91) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 15 Oct 2020 14:20:38 -0700 Subject: Re: [PATCH 5/8] x86/clear_page: add clear_page_uncached() To: Borislav Petkov Cc: Andy Lutomirski , Andy Lutomirski , LKML , Linux-MM , "Kirill A. Shutemov" , Michal Hocko , Boris Ostrovsky , Konrad Rzeszutek Wilk , Thomas Gleixner , Ingo Molnar , X86 ML , "H. Peter Anvin" , Arnd Bergmann , Andrew Morton , Ira Weiny , linux-arch References: <20201014195823.GC18196@zn.tnic> <22E29783-F1F5-43DA-B35F-D75FB247475D@amacapital.net> <20201014211214.GD18196@zn.tnic> <3de58840-1f4c-566b-3a66-46d57475820c@oracle.com> <20201015103535.GC11838@zn.tnic> From: Ankur Arora Message-ID: <593f3b75-678c-1cd4-a7f0-55257dc84caf@oracle.com> Date: Thu, 15 Oct 2020 14:20:36 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20201015103535.GC11838@zn.tnic> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9775 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 mlxscore=0 spamscore=0 adultscore=0 suspectscore=0 phishscore=0 bulkscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010150141 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9775 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 clxscore=1015 impostorscore=0 phishscore=0 malwarescore=0 bulkscore=0 priorityscore=1501 mlxscore=0 suspectscore=0 spamscore=0 adultscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010150141 Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On 2020-10-15 3:35 a.m., Borislav Petkov wrote: > On Wed, Oct 14, 2020 at 08:37:44PM -0700, Ankur Arora wrote: >> I don't disagree but I think the selection of cached/uncached route should >> be made where we have enough context available to be able to choose to do >> this. >> >> This could be for example, done in mm_populate() or gup where if say the >> extent is larger than LLC-size, it takes the uncached path. > > Are there examples where we don't know the size? The case I was thinking of was that clear_huge_page() or faultin_page() would know the size to a page unit, while the higher level function would know the whole extent and could optimize differently based on that. Thanks Ankur >