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=-5.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 28B2BC433E0 for ; Thu, 18 Mar 2021 08:14:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8147364EF6 for ; Thu, 18 Mar 2021 08:14:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8147364EF6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id D370C6B0070; Thu, 18 Mar 2021 04:14:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CBDF56B0071; Thu, 18 Mar 2021 04:14:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B10A66B0072; Thu, 18 Mar 2021 04:14:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0139.hostedemail.com [216.40.44.139]) by kanga.kvack.org (Postfix) with ESMTP id 9108F6B0070 for ; Thu, 18 Mar 2021 04:14:35 -0400 (EDT) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 51543181AF5C7 for ; Thu, 18 Mar 2021 08:14:35 +0000 (UTC) X-FDA: 77932283268.03.AAF3F4B Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) by imf01.hostedemail.com (Postfix) with ESMTP id F10DF5001522 for ; Thu, 18 Mar 2021 08:14:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616055274; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=15NAKS9Isxz1mUr9bz1U2OlYkIPx+9vW+iRsoYJamYs=; b=Cod5nbCr9zrYPSK0nvHym2lPE22sJ1CdNYtHtyLSuIk4dSq/A1PdZD2PW8ZOEwL2Vm74I/ 8z2KbFX8F2ffoUsg1AyMTMlu/UWg4w7nrfy4u/XBpXlLnshUu+2yJ7eVsQfm8RCaVZXJmI 5ZTX30saiFFkz+Tt3gafveNF8GrQNI4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-452-gDW63DTcOSiKUSClNJiSTA-1; Thu, 18 Mar 2021 04:14:32 -0400 X-MC-Unique: gDW63DTcOSiKUSClNJiSTA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1974D8189CD; Thu, 18 Mar 2021 08:14:30 +0000 (UTC) Received: from [10.36.113.61] (ovpn-113-61.ams2.redhat.com [10.36.113.61]) by smtp.corp.redhat.com (Postfix) with ESMTP id 456C21F41B; Thu, 18 Mar 2021 08:14:27 +0000 (UTC) To: Matthew Wilcox Cc: Aili Yao , akpm@linux-foundation.org, naoya.horiguchi@nec.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, yangfeng1@kingsoft.com, sunhao2@kingsoft.com, Oscar Salvador , Mike Kravetz References: <20210317163714.328a038d@alex-virtual-machine> <20a0d078-f49d-54d6-9f04-f6b41dd51e5f@redhat.com> <20210318044600.GJ3420@casper.infradead.org> From: David Hildenbrand Organization: Red Hat GmbH Subject: Re: [PATCH] mm/gup: check page posion status for coredump. Message-ID: <5cc2ccb8-16bc-bbbf-6c94-124be1d95458@redhat.com> Date: Thu, 18 Mar 2021 09:14:26 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <20210318044600.GJ3420@casper.infradead.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Stat-Signature: zd67k4q4amnmcdehs83nmr3bshsudjbz X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: F10DF5001522 Received-SPF: none (redhat.com>: No applicable sender policy available) receiver=imf01; identity=mailfrom; envelope-from=""; helo=us-smtp-delivery-124.mimecast.com; client-ip=63.128.21.124 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1616055273-408264 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 18.03.21 05:46, Matthew Wilcox wrote: > On Wed, Mar 17, 2021 at 10:12:02AM +0100, David Hildenbrand wrote: >>> + if (IS_ENABLED(CONFIG_MEMORY_FAILURE) && ret =3D=3D 1) { >>> + if (unlikely(PageHuge(page) && PageHWPoison(compound_head(page)))) >>> + ret =3D 0; >>> + else if (unlikely(PageHWPoison(page))) >>> + ret =3D 0; >>> + } >> >> I wonder if a simple >> >> if (PageHWPoison(compound_head(page))) >> ret =3D 0; >> >> won't suffice. But I guess the "issue" is compound pages that are not = huge >> pages or transparent huge pages. >=20 > THPs don't set the HWPoison bit on the head page. >=20 > https://lore.kernel.org/linux-mm/20210316140947.GA3420@casper.infradead= .org/ Oh, okay -- I was missing that we actually already set the HWPoison bit=20 before trying to split via TestSetPageHWPoison(). I thought for a second=20 that if splitting fails, we don't set any HWPoison bit. --=20 Thanks, David / dhildenb