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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 13BD4C3F2D4 for ; Mon, 2 Mar 2020 02:29:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD4F22469C for ; Mon, 2 Mar 2020 02:28:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ZVPuK9Cy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726764AbgCBC26 (ORCPT ); Sun, 1 Mar 2020 21:28:58 -0500 Received: from mail-io1-f47.google.com ([209.85.166.47]:45460 "EHLO mail-io1-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726695AbgCBC26 (ORCPT ); Sun, 1 Mar 2020 21:28:58 -0500 Received: by mail-io1-f47.google.com with SMTP id w9so9801102iob.12 for ; Sun, 01 Mar 2020 18:28:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=J0980YMlHpI5mQNZ0x9GeM8jDUtERfj40WG6yxOZ0aY=; b=ZVPuK9Cy6YB7vebkLEbrOwTXVyBu8gFrwE59AamU37CWWkff8x7Nz9OrLpABRZvRNu Pb3hTyOmquoMqg6fYDpLXzZKIS18EIsVBNlw4w7e1jVMxzPPHxUUx5BY/tB1haEkdx5A C9Lyn+MwiksraxbOYHCeQVmEzRn0gHrj8/KYmTGgZwh21HwBhvOqvmvRp4tpJcZ1CLtt 3Jie6KMQMVIHJ5Y3QRs3VB5kSNfEx35KSrmecdXlsjQYt8MIBcn162INGDu613w1S4Yg CCN3yakBD1jF+fjRyKiMsxr3FPLX0jVTkVX1SDFTbag3JMWExvs4Yegfsb3az/rs58JF u+ww== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=J0980YMlHpI5mQNZ0x9GeM8jDUtERfj40WG6yxOZ0aY=; b=FAsw66oaOUgzf41ux0vuCml729DBxZ+gamLjv6RfABvD/d3eOvUYPFC5rpqHisyo9s AdsmSbaPG+ZULLcj6WiJ/S76bkD63rcUbnyO5ePaacYBedbGRwC54DlDtyVYQxM8ejox EKysYHzQ6AuaN7ithx7CF9tTHiY0sKPtEMENEtmcCDjgRBM7Z78cGnQo7bBysS9QJRvi BVb3wUonAyyhb8Hocz2thgGx5gWTmeLU5sKOlJ+RO4y31XaBjQq/3+FglF4x9QRbDlQu 7QFhb2KhuuW1du6W3TkJmpaSvcNRbEVceVJGdSUuqAuAjn+BYLnxcz5PykEpD4orsjTA G5hA== X-Gm-Message-State: APjAAAXx2FqJnlyTLR4qlnhVvGKtPoVgT2QjTBlOUMF/MF8coRewJoYq I+LKIAqW2g6C29aJlmlJngMQ9k/2h7NlRCjBfw== X-Google-Smtp-Source: APXvYqwsPpzc21trMG0QKeGzBsTS1cZD0vaNdLT/wd0/aNF6rYH9AQ2YuIQHTk97BmbShE1c237Q2qHWcKrh6dppAAY= X-Received: by 2002:a6b:3103:: with SMTP id j3mr9726379ioa.39.1583116137647; Sun, 01 Mar 2020 18:28:57 -0800 (PST) MIME-Version: 1.0 References: <1582889550-9101-1-git-send-email-kernelfans@gmail.com> <1582889550-9101-3-git-send-email-kernelfans@gmail.com> <20200228223446.GA4658@iweiny-DESK2.sc.intel.com> In-Reply-To: <20200228223446.GA4658@iweiny-DESK2.sc.intel.com> From: Pingfan Liu Date: Mon, 2 Mar 2020 10:28:45 +0800 Message-ID: Subject: Re: [PATCHv5 2/3] mm/gup: fix omission of check on FOLL_LONGTERM in gup fast path To: Ira Weiny Cc: Linux-MM , Andrew Morton , Mike Rapoport , Dan Williams , Matthew Wilcox , John Hubbard , "Aneesh Kumar K.V" , Christoph Hellwig , Shuah Khan , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Feb 29, 2020 at 6:34 AM Ira Weiny wrote: > > On Fri, Feb 28, 2020 at 07:32:29PM +0800, Pingfan Liu wrote: > > FOLL_LONGTERM suggests a pin which is going to be given to hardware and > > can't move. It would truncate CMA permanently and should be excluded. > > I don't understand what is 'truncated' here? a pinned page will truncate a continuous area, and prevent CMA to reclaim the continuous area. > > I generally agree with Jason that this is going to be confusing to the user. Please see the reply in anothe mail. Thanks, Pingfan [...]