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=-0.7 required=3.0 tests=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 E2928C169F9 for ; Wed, 19 Feb 2020 18:31:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C805720801 for ; Wed, 19 Feb 2020 18:31:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726691AbgBSSbs (ORCPT ); Wed, 19 Feb 2020 13:31:48 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:32648 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726609AbgBSSbs (ORCPT ); Wed, 19 Feb 2020 13:31:48 -0500 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 01JIMMO5125013 for ; Wed, 19 Feb 2020 13:31:46 -0500 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0b-001b2d01.pphosted.com with ESMTP id 2y8ubsfvqq-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 19 Feb 2020 13:31:46 -0500 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 19 Feb 2020 18:31:41 -0000 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 01JIVemN28770560 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 19 Feb 2020 18:31:40 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 906E2AE051; Wed, 19 Feb 2020 18:31:40 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4AE03AE045; Wed, 19 Feb 2020 18:31:38 +0000 (GMT) Received: from linux.ibm.com (unknown [9.148.205.46]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Wed, 19 Feb 2020 18:31:38 +0000 (GMT) Date: Wed, 19 Feb 2020 19:31:35 +0100 From: Mike Rapoport To: Dan Williams Cc: Baoquan He , Linux Kernel Mailing List , Linux MM , Andrew Morton , Wei Yang , David Hildenbrand , Oscar Salvador , Michal Hocko Subject: Re: [PATCH v2 RESEND] mm/sparsemem: pfn_to_page is not valid yet on SPARSEMEM References: <20200219030454.4844-1-bhe@redhat.com> <20200219085700.GB32242@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-TM-AS-GCONF: 00 x-cbid: 20021918-0020-0000-0000-000003ABB057 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20021918-0021-0000-0000-00002203B29E Message-Id: <20200219183135.GA10266@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.572 definitions=2020-02-19_05:2020-02-19,2020-02-19 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 lowpriorityscore=0 clxscore=1015 adultscore=0 bulkscore=0 priorityscore=1501 mlxscore=0 impostorscore=0 suspectscore=1 spamscore=0 mlxlogscore=665 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002190140 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 19, 2020 at 08:37:25AM -0800, Dan Williams wrote: > On Wed, Feb 19, 2020 at 12:57 AM Mike Rapoport wrote: > > > > On Tue, Feb 18, 2020 at 07:25:15PM -0800, Dan Williams wrote: > > > On Tue, Feb 18, 2020 at 7:05 PM Baoquan He wrote: > > > > > > > > From: Wei Yang > > > > > > > > When we use SPARSEMEM instead of SPARSEMEM_VMEMMAP, pfn_to_page() > > > > doesn't work before sparse_init_one_section() is called. This leads to a > > > > crash when hotplug memory: > > > > > > I'd also add: > > > > > > "On x86 the impact is limited to x86_32 builds, or x86_64 > > > configurations that override the default setting for > > > SPARSEMEM_VMEMMAP". > > > > Do we also want to check how it affects, say, arm64, ia64 and ppc? ;-) > > Sure, I just did not take the time to look up their respective default > stances on SPARSEMEM_VMEMMAP. For a distro looking to backport this > commit I think it's helpful for them to understand if they are exposed > or not. Looks like only i386_defconfig does not enable SPARSEMEM_VMEMMAP. All the rest may have it disabled only with manual override. -- Sincerely yours, Mike.