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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 D0ABFC04AB4 for ; Tue, 14 May 2019 04:48:00 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 548EA2086A for ; Tue, 14 May 2019 04:48:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 548EA2086A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4534tk1VPmzDqM1 for ; Tue, 14 May 2019 14:47:58 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=linux.ibm.com (client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com; envelope-from=aneesh.kumar@linux.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4534sH4jxszDqGS for ; Tue, 14 May 2019 14:46:43 +1000 (AEST) Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x4E4h8JO060014 for ; Tue, 14 May 2019 00:46:41 -0400 Received: from e33.co.us.ibm.com (e33.co.us.ibm.com [32.97.110.151]) by mx0b-001b2d01.pphosted.com with ESMTP id 2sfh3kkh72-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 14 May 2019 00:46:40 -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) Tue, 14 May 2019 05:46:38 +0100 Received: from b03ledav002.gho.boulder.ibm.com (b03ledav002.gho.boulder.ibm.com [9.17.130.233]) by b03cxnp08025.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x4E4kbOo10551696 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 14 May 2019 04:46:38 GMT Received: from b03ledav002.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D3310136055; Tue, 14 May 2019 04:46:37 +0000 (GMT) Received: from b03ledav002.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6216913604F; Tue, 14 May 2019 04:46:36 +0000 (GMT) Received: from [9.80.230.27] (unknown [9.80.230.27]) by b03ledav002.gho.boulder.ibm.com (Postfix) with ESMTP; Tue, 14 May 2019 04:46:35 +0000 (GMT) Subject: Re: [PATCH] mm/nvdimm: Use correct #defines instead of opencoding To: Dan Williams References: <20190514025604.9997-1-aneesh.kumar@linux.ibm.com> From: "Aneesh Kumar K.V" Date: Tue, 14 May 2019 10:16:34 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 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: 19051404-0036-0000-0000-00000AB9189C X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00011095; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000285; SDB=6.01203030; UDB=6.00631440; IPR=6.00983952; MB=3.00026878; MTD=3.00000008; XFM=3.00000015; UTC=2019-05-14 04:46:39 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19051404-0037-0000-0000-00004BC780CB Message-Id: <02d1d14d-650b-da38-0828-1af330f594d5@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-05-14_02:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 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-1905140032 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Linux MM , linuxppc-dev , linux-nvdimm Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 5/14/19 9:42 AM, Dan Williams wrote: > On Mon, May 13, 2019 at 9:05 PM Aneesh Kumar K.V > wrote: >> >> On 5/14/19 9:28 AM, Dan Williams wrote: >>> On Mon, May 13, 2019 at 7:56 PM Aneesh Kumar K.V >>> wrote: >>>> >>>> The nfpn related change is needed to fix the kernel message >>>> >>>> "number of pfns truncated from 2617344 to 163584" >>>> >>>> The change makes sure the nfpns stored in the superblock is right value. >>>> >>>> Signed-off-by: Aneesh Kumar K.V >>>> --- >>>> drivers/nvdimm/pfn_devs.c | 6 +++--- >>>> drivers/nvdimm/region_devs.c | 8 ++++---- >>>> 2 files changed, 7 insertions(+), 7 deletions(-) >>>> >>>> diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c >>>> index 347cab166376..6751ff0296ef 100644 >>>> --- a/drivers/nvdimm/pfn_devs.c >>>> +++ b/drivers/nvdimm/pfn_devs.c >>>> @@ -777,8 +777,8 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) >>>> * when populating the vmemmap. This *should* be equal to >>>> * PMD_SIZE for most architectures. >>>> */ >>>> - offset = ALIGN(start + reserve + 64 * npfns, >>>> - max(nd_pfn->align, PMD_SIZE)) - start; >>>> + offset = ALIGN(start + reserve + sizeof(struct page) * npfns, >>>> + max(nd_pfn->align, PMD_SIZE)) - start; >>> >>> No, I think we need to record the page-size into the superblock format >>> otherwise this breaks in debug builds where the struct-page size is >>> extended. >>> >>>> } else if (nd_pfn->mode == PFN_MODE_RAM) >>>> offset = ALIGN(start + reserve, nd_pfn->align) - start; >>>> else >>>> @@ -790,7 +790,7 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) >>>> return -ENXIO; >>>> } >>>> >>>> - npfns = (size - offset - start_pad - end_trunc) / SZ_4K; >>>> + npfns = (size - offset - start_pad - end_trunc) / PAGE_SIZE; >>> >>> Similar comment, if the page size is variable then the superblock >>> needs to explicitly account for it. >>> >> >> PAGE_SIZE is not really variable. What we can run into is the issue you >> mentioned above. The size of struct page can change which means the >> reserved space for keeping vmemmap in device may not be sufficient for >> certain kernel builds. >> >> I was planning to add another patch that fails namespace init if we >> don't have enough space to keep the struct page. >> >> Why do you suggest we need to have PAGE_SIZE as part of pfn superblock? > > So that the kernel has a chance to identify cases where the superblock > it is handling was created on a system with different PAGE_SIZE > assumptions. > The reason to do that is we don't have enough space to keep struct page backing the total number of pfns? If so, what i suggested above should handle that. or are you finding any other reason why we should fail a namespace init with a different PAGE_SIZE value? My another patch handle the details w.r.t devdax alignment for which devdax got created with PAGE_SIZE 4K but we are now trying to load that in a kernel with PAGE_SIZE 64k. -aneesh