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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 A7449C31E4B for ; Fri, 14 Jun 2019 16:55:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7FED92184D for ; Fri, 14 Jun 2019 16:55:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726581AbfFNQza (ORCPT ); Fri, 14 Jun 2019 12:55:30 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:44334 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726262AbfFNQz2 (ORCPT ); Fri, 14 Jun 2019 12:55:28 -0400 Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x5EGrUKa057148 for ; Fri, 14 Jun 2019 12:55:27 -0400 Received: from e33.co.us.ibm.com (e33.co.us.ibm.com [32.97.110.151]) by mx0a-001b2d01.pphosted.com with ESMTP id 2t4e0cv1ms-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 14 Jun 2019 12:55:27 -0400 Received: from localhost by e33.co.us.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) Fri, 14 Jun 2019 17:55:23 +0100 Received: from b03ledav001.gho.boulder.ibm.com (b03ledav001.gho.boulder.ibm.com [9.17.130.232]) by b03cxnp07029.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x5EGtM0g34144540 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 14 Jun 2019 16:55:22 GMT Received: from b03ledav001.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 622AB6E059; Fri, 14 Jun 2019 16:55:22 +0000 (GMT) Received: from b03ledav001.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BF1B66E054; Fri, 14 Jun 2019 16:55:19 +0000 (GMT) Received: from [9.199.60.77] (unknown [9.199.60.77]) by b03ledav001.gho.boulder.ibm.com (Postfix) with ESMTP; Fri, 14 Jun 2019 16:55:19 +0000 (GMT) Subject: Re: [PATCH -next] mm/hotplug: skip bad PFNs from pfn_to_online_page() To: Dan Williams Cc: Oscar Salvador , Qian Cai , Andrew Morton , Linux MM , Linux Kernel Mailing List , jmoyer , linux-nvdimm References: <1560366952-10660-1-git-send-email-cai@lca.pw> <1560376072.5154.6.camel@lca.pw> <87lfy4ilvj.fsf@linux.ibm.com> <20190614153535.GA9900@linux> <24fcb721-5d50-2c34-f44b-69281c8dd760@linux.ibm.com> From: "Aneesh Kumar K.V" Date: Fri, 14 Jun 2019 22:25:18 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19061416-0036-0000-0000-00000ACBC6A1 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00011261; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000286; SDB=6.01217925; UDB=6.00640497; IPR=6.00999046; MB=3.00027312; MTD=3.00000008; XFM=3.00000015; UTC=2019-06-14 16:55:25 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19061416-0037-0000-0000-00004C39CFB8 Message-Id: <16108dac-a4ca-aa87-e3b0-a79aebdcfafd@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-14_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=27 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906140137 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/14/19 10:06 PM, Dan Williams wrote: > On Fri, Jun 14, 2019 at 9:26 AM Aneesh Kumar K.V > wrote: >> Why not let the arch >> arch decide the SUBSECTION_SHIFT and default to one subsection per >> section if arch is not enabled to work with subsection. > > Because that keeps the implementation from ever reaching a point where > a namespace might be able to be moved from one arch to another. If we > can squash these arch differences then we can have a common tool to > initialize namespaces outside of the kernel. The one wrinkle is > device-dax that wants to enforce the mapping size, The fsdax have a much bigger issue right? The file system block size is the same as PAGE_SIZE and we can't make it portable across archs that support different PAGE_SIZE? -aneesh