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=-6.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 5CF6FC433ED for ; Fri, 14 May 2021 19:16:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2D2D161278 for ; Fri, 14 May 2021 19:16:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233449AbhENTRz (ORCPT ); Fri, 14 May 2021 15:17:55 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:41498 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229610AbhENTRx (ORCPT ); Fri, 14 May 2021 15:17:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621019801; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=R27Jf03ZxREnKxwqc3tfY/ljdTBme23N34D66vuvIQg=; b=Ow3SrpMTq+C+149YXjvsGd3ozjSYy+P7XYbL32TSDl+RSYcX1qCzuU/q9J3EU6kuqiJZtd BsPPd7WzlMUjlfcqurGUvXAQ0eU3RfYZdoDx1hKiwNJEKnEJubWarev8Pcdee2FXT/49eS JEFdkvN36RVfGYJ+0sOxxLCrLb8inww= Received: from mail-qt1-f197.google.com (mail-qt1-f197.google.com [209.85.160.197]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-477-El8uDjjVPU6KTbnK_GampA-1; Fri, 14 May 2021 15:16:39 -0400 X-MC-Unique: El8uDjjVPU6KTbnK_GampA-1 Received: by mail-qt1-f197.google.com with SMTP id v13-20020ac8578d0000b02901e4f5d48831so311181qta.14 for ; Fri, 14 May 2021 12:16:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=R27Jf03ZxREnKxwqc3tfY/ljdTBme23N34D66vuvIQg=; b=UtL0OZUD7vk/oPVuemriv7w+odXt61WtKaMKBMxcgI4D9fjMVRSj7uBo9lQWbldiZp MmXCxKqOg0PKAQsenF7NhhJhslqe4JxVqVtXbsK/DOZpLN+s2PXIllelGgHmHpPbdf0v 3HBLn6KHdExsQNjpzWl1Mk7KKBZUwFs7zJo9YuEtZ9v8DQaBWJripvOwAKucc3DLlhex 0eqFBZyJJYmxiHkyp5iWwl85H84ErnwdrKdd5kAjZlisY3R/nR8eGee+gaJa7W6u4IeE 1VKosCdGhg36JGRywHo2t0Ey54vu9/Irh8Doln3kwckPYVgn4bMOeGqtV4iFPpegZKEA Xvfg== X-Gm-Message-State: AOAM533sLfLG1JpkuiH1IssimePRqwhzO0eKL5g9tSdc88L+LstXcWxw M0iZBARXFfnLiYiTJ+AyT5aOGsdPIyMQgmR1/iJZFFwMKsW6TNqCehemRRUIYTAu/Evf8+5dGz7 0nZMkX4ftXMl94I36il9uq4yf X-Received: by 2002:ae9:e80c:: with SMTP id a12mr32290581qkg.85.1621019799290; Fri, 14 May 2021 12:16:39 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxJs+ha/rpm7/oDhLt+mOMNO1Kxmt5d5fuW6jdVLELsSygkTzBiRgTBeOiTpRSfxRjcymOgfA== X-Received: by 2002:ae9:e80c:: with SMTP id a12mr32290560qkg.85.1621019799027; Fri, 14 May 2021 12:16:39 -0700 (PDT) Received: from t490s (bras-base-toroon474qw-grc-72-184-145-4-219.dsl.bell.ca. [184.145.4.219]) by smtp.gmail.com with ESMTPSA id i11sm5069427qtv.8.2021.05.14.12.16.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 14 May 2021 12:16:38 -0700 (PDT) Date: Fri, 14 May 2021 15:16:36 -0400 From: Peter Xu To: Mike Kravetz Cc: Mina Almasry , Axel Rasmussen , Linux-MM , Andrew Morton , open list Subject: Re: [PATCH] mm, hugetlb: fix resv_huge_pages underflow on UFFDIO_COPY Message-ID: References: <20210513234309.366727-1-almasrymina@google.com> <09dc0712-48e8-8ba2-f170-4c2febcfff83@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 14, 2021 at 10:56:36AM -0700, Mike Kravetz wrote: > Since this is a shared mapping, can we not have a 'regular' mapping to > the same range that is uffd registered? And, that regular mappings could > fault and race with the uffd copy code? Yeah we can.. Please ignore the paragraph in the parenthesis. Sorry. -- Peter Xu