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=-0.3 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 166D5C3404D for ; Wed, 19 Feb 2020 01:58:32 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D40A224655 for ; Wed, 19 Feb 2020 01:58:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ipHlH/Al" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D40A224655 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id A5B2710FC3581; Tue, 18 Feb 2020 17:59:23 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=2607:f8b0:4864:20::442; helo=mail-pf1-x442.google.com; envelope-from=jencce.kernel@gmail.com; receiver= Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id B081C10FC340D for ; Tue, 18 Feb 2020 17:59:20 -0800 (PST) Received: by mail-pf1-x442.google.com with SMTP id 185so11665855pfv.3 for ; Tue, 18 Feb 2020 17:58:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=q/nY1Mf51kH8KT0v62tDiqkFUg4146cYnGwpmJwHyYo=; b=ipHlH/AlxVQ/IulE7p5AjzOFHiVR1RBrVYYtMyUoV1UQoG/6dZkSxq2PGqL2fniBgm p2Y3huDQAm29/M/8lvlIqo28KOk7mjIsnca2skalBXejbHNR1Lrgos+j48iiEPvhqLDw N6lchqBHGjjVN/a0DsS4yGeBI/RdwNASQm1aspA3tBfW0yDxxMFQxIwSs8xp7NcmY1D/ lCOit0ez4+qPD2E7FNkgD5GxN4hi4xESTM/cOe6e6LQV233A0JernCGhcyycJGO0ApCc c7wG+rJ1X+e7UIgAO7ZZ+RZZExBkp5m2WFgdAws1sbupJEUXH/dcteNZKPo27wy5uELj Mwmg== 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=q/nY1Mf51kH8KT0v62tDiqkFUg4146cYnGwpmJwHyYo=; b=AnbvXgkNarbvPT/oI02pLlQyuDn6scyp06qSrUC2vI56IQ/tbkE9BLJZoN4l2cRe4A gfe76Uou2rMZDTm+CNMz1HzR2K9yRoU+O9fvJA6Yke/dBQK34Uc4jgn08pwdPHXWXjam lwVU+OJa95nTRNr51eOYHt4ESYfbD7IT4A/hl3TLoM+AG+I19/YD8coMafYC32dHbMr3 4iEPCVByhaaXN83y0p2ay4KZVPklsaLy0P2P38bPJDpxCfVX1DEZFwKfHum8IPiRVC0z LwvwLu40yBpBNA8+IHCGN7WiGt31vfHji1/Nl3FEyGoA02zKymA54TdHg7TvQ0F1tWGt AI/w== X-Gm-Message-State: APjAAAWVwLwIRcucmR+9jUo/Y738lEl6zE4Ocxx1G0ZJm/hD7sjCF/gd REiwgfL41gJF30ex0TDiM4g= X-Google-Smtp-Source: APXvYqzFJQ7t+g8cJNhe0uBXgIH3F++H+a+3qLANXSylYjhWNApUO0k8Gw5fe0DVzEJDNArl3M7gpg== X-Received: by 2002:aa7:9629:: with SMTP id r9mr24801465pfg.51.1582077507872; Tue, 18 Feb 2020 17:58:27 -0800 (PST) Received: from localhost ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id e2sm206430pjs.25.2020.02.18.17.58.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 18 Feb 2020 17:58:27 -0800 (PST) Date: Wed, 19 Feb 2020 09:58:19 +0800 From: Murphy Zhou To: Jeff Moyer Subject: Re: [PATCH] mm: get rid of WARN if failed to cow user pages Message-ID: <20200219015819.otdnknxpyo52txy7@xzhoux.usersys.redhat.com> References: <20191225054227.gii6ctjkuddjnprs@xzhoux.usersys.redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Message-ID-Hash: M5NRRIRN63XXQOGYUTFFNXNJKFQ66KDY X-Message-ID-Hash: M5NRRIRN63XXQOGYUTFFNXNJKFQ66KDY X-MailFrom: jencce.kernel@gmail.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; suspicious-header CC: linux-nvdimm , Jia He , Linux MM , "Shutemov, Kirill" , Linux Kernel Mailing List X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Tue, Feb 18, 2020 at 04:09:30PM -0500, Jeff Moyer wrote: > Dan Williams writes: > > > [ drop Ross, add Kirill, linux-mm, and lkml ] > > > > On Tue, Dec 24, 2019 at 9:42 PM Murphy Zhou wrote: > >> > >> By running xfstests with fsdax enabled, generic/437 always hits this > >> warning[1] since this commit: > >> > >> commit 83d116c53058d505ddef051e90ab27f57015b025 > >> Author: Jia He > >> Date: Fri Oct 11 22:09:39 2019 +0800 > >> > >> mm: fix double page fault on arm64 if PTE_AF is cleared > >> > >> Looking at the test program[2] generic/437 uses, it's pretty easy > >> to hit this warning. Remove this WARN as it seems not necessary. > > > > This is not sufficient justification. Does this same test fail without > > DAX? If not, why not? At a minimum you need to explain why this is not > > indicating a problem. > > I ran into this, too, and Kirill has posted a patch[1] to fix the issue. > Note that it's a potential data corrupter, so just removing the warning > is NOT the right approach. :) Agree :) Thanks! > > -Jeff > > [1] https://lore.kernel.org/linux-mm/20200218154151.13349-1-kirill.shutemov@linux.intel.com/T/#u > _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org