From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from g4t3425.houston.hpe.com (g4t3425.houston.hpe.com [15.241.140.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 3A90021B02B8B for ; Thu, 29 Jun 2017 15:48:27 -0700 (PDT) Subject: Re: [PATCH v4 12/16] libnvdimm, nfit: enable support for volatile ranges References: <149875877608.10031.17813337234536358002.stgit@dwillia2-desk3.amr.corp.intel.com> <149875884190.10031.6179599135820559644.stgit@dwillia2-desk3.amr.corp.intel.com> <595552F5.5040008@hpe.com> <59556E37.80808@hpe.com> <595580A6.9000004@hpe.com> From: Linda Knippers Message-ID: Date: Thu, 29 Jun 2017 18:49:52 -0400 MIME-Version: 1.0 In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Dan Williams Cc: Jan Kara , Matthew Wilcox , X86 ML , "linux-kernel@vger.kernel.org" , "linux-nvdimm@lists.01.org" , Al Viro , linux-fsdevel , Christoph Hellwig List-ID: On 6/29/2017 6:43 PM, Dan Williams wrote: > On Thu, Jun 29, 2017 at 3:35 PM, Linda Knippers wrote: >> On 06/29/2017 06:28 PM, Dan Williams wrote: >>> On Thu, Jun 29, 2017 at 3:12 PM, Linda Knippers wrote: >>> [..] >>>>> The /dev/pmem >>>>> device name just tells you that your block device is hosted by a >>>>> driver that knows how to handle persistent memory constraints, but any >>>>> other details about the nature of the address range need to come from >>>>> other sources of information, and potentially information sources that >>>>> the kernel does not know about. >>>> >>>> >>>> I'm asking about the other source of information in this specific case >>>> where we're exposing pmem devices that will never ever be persistent. >>>> Before we add these devices, I think we should be able to tell the user >>>> how they can know the properties of the underlying device. >>> >>> The only way I can think to indicate this is with a platform + device >>> whitelist in a tool like ndctl. Where the tool says "yes, these >>> xyz-vendor DIMMs on this abc-vendor platform with this 123-version >>> BIOS" is a known good persistent configuration. >> >> Doesn't the kernel know that something will never ever be persistent >> because the NFIT type says NFIT_SPA_VDISK, NFIT_SPA_VCD, or NFIT_SPA_VOLATILE? >> That's the case I'm asking about here. In this patch, you're adding support >> for creating /dev/pmem devices for those address ranges. My question is >> how the admin/user knows that those devices will never ever be persistent. > > The parent region of the namespace will have a 'volatile' type: > > # cat /sys/bus/nd/devices/region0/devtype > nd_volatile If all I know is the /dev/pmem device name, how do I find that? -- ljk > >> I don't think we need ndctl to know which vendors' hardware/firmware >> actually works as advertised. > > Certification stickers is what I was thinking, but I was missing your > direction question. > _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751776AbdF2WuD (ORCPT ); Thu, 29 Jun 2017 18:50:03 -0400 Received: from g4t3425.houston.hpe.com ([15.241.140.78]:4440 "EHLO g4t3425.houston.hpe.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751537AbdF2WuA (ORCPT ); Thu, 29 Jun 2017 18:50:00 -0400 X-Greylist: delayed 5594 seconds by postgrey-1.27 at vger.kernel.org; Thu, 29 Jun 2017 18:50:00 EDT Authentication-Results: hpe.com; dkim=none (message not signed) header.d=none;hpe.com; dmarc=none action=none header.from=hpe.com; Subject: Re: [PATCH v4 12/16] libnvdimm, nfit: enable support for volatile ranges To: Dan Williams References: <149875877608.10031.17813337234536358002.stgit@dwillia2-desk3.amr.corp.intel.com> <149875884190.10031.6179599135820559644.stgit@dwillia2-desk3.amr.corp.intel.com> <595552F5.5040008@hpe.com> <59556E37.80808@hpe.com> <595580A6.9000004@hpe.com> CC: "linux-nvdimm@lists.01.org" , Jan Kara , Matthew Wilcox , X86 ML , "linux-kernel@vger.kernel.org" , Al Viro , linux-fsdevel , Christoph Hellwig From: Linda Knippers Message-ID: Date: Thu, 29 Jun 2017 18:49:52 -0400 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [73.60.235.182] X-ClientProxiedBy: DM5PR06CA0066.namprd06.prod.outlook.com (10.168.110.156) To DF4PR84MB0075.NAMPRD84.PROD.OUTLOOK.COM (10.162.192.152) X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: a20e3fd6-75c6-4b2b-14c7-08d4bf412a67 X-MS-Office365-Filtering-HT: Tenant X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:(300000500095)(300135000095)(300000501095)(300135300095)(22001)(300000502095)(300135100095)(300000503095)(300135400095)(48565401081)(201703131423075)(201703031133081)(300000504095)(300135200095)(300000505095)(300135600095)(300000506095)(300135500095);SRVR:DF4PR84MB0075; X-Microsoft-Exchange-Diagnostics: 1;DF4PR84MB0075;3: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 X-MS-TrafficTypeDiagnostic: DF4PR84MB0075: X-Microsoft-Exchange-Diagnostics: 1;DF4PR84MB0075;25: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 X-Microsoft-Exchange-Diagnostics: 1;DF4PR84MB0075;31: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 X-Microsoft-Exchange-Diagnostics: 1;DF4PR84MB0075;20: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 X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:(227479698468861)(133145235818549)(236129657087228)(48057245064654); X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(100000700101)(100105000095)(100000701101)(100105300095)(100000702101)(100105100095)(6040450)(601004)(2401047)(5005006)(8121501046)(3002001)(93006095)(93001095)(100000703101)(100105400095)(10201501046)(6055026)(6041248)(20161123562025)(20161123558100)(201703131423075)(201702281528075)(201703061421075)(201703061406153)(20161123564025)(20161123560025)(20161123555025)(6072148)(100000704101)(100105200095)(100000705101)(100105500095);SRVR:DF4PR84MB0075;BCL:0;PCL:0;RULEID:(100000800101)(100110000095)(100000801101)(100110300095)(100000802101)(100110100095)(100000803101)(100110400095)(100000804101)(100110200095)(100000805101)(100110500095);SRVR:DF4PR84MB0075; X-Microsoft-Exchange-Diagnostics: =?utf-8?B?MTtERjRQUjg0TUIwMDc1OzQ6WC9CSWNsdVZneUpmV1pqSUxyL3BuTHZDZDJK?= =?utf-8?B?cDVtOFZ4cmpuckNaS3J3NVRKMEhQNjd4RDkxaDM4V2IrL3duclFZZ0R1VkRo?= =?utf-8?B?MEtnaEs0UTMyZkpXUCtWQy9ETGdDekViY1hZbVdodGNwenpBNmxhRGNIbXZl?= =?utf-8?B?RVZnb0N6Mkd5NGdUVW5FZDVUM212TGpKcXNwbDFEZTNMUzhSRUsxU1JGOTdD?= =?utf-8?B?L2g4QmN2R1E1ZlhwSit1VjE4cENEemtuZEFGN0tzODlJc0tqam15MFpyZmNr?= =?utf-8?B?Z005cHk4cnUyTzU0QVpRemF2dXVPMkg0M3hqdXBpWVFhM20vTm12Undmdk9V?= =?utf-8?B?RVFWa0VQbTdUcFpoM2pWSG5aV3RpN2NocU11a25OMGJNNWNGTTU1aFNaRTQ1?= =?utf-8?B?UzJrMDZ5cG9iSUR4QlIrWCsyN2RjdWxIbXpmbnNqT3VOdDBRUVhNMmRDWWVL?= =?utf-8?B?VnY4SXVTU1Irb0xiV0EwOW5neUpwSFB6OG5ha3FDcEp0c1pBcFdnOERPVyt1?= =?utf-8?B?d29RTFMrbmJlNSt0VUxlRkg1QmFSL3pJWmxoRm1DOXdzdmcrSGtUT1d3Z3Ny?= =?utf-8?B?RVdLOXN0NU9BelB2R01zZmNJRGE3UkhPbDNLTktHTXMxblNjc1dTcjQxSE4y?= =?utf-8?B?TEcrQW5rcmw0bWZXcmdsTEFpT0dRNkZ5NVZEeHI2NjljQzltcnJFOHE1RUR6?= =?utf-8?B?WHBLTldoUHMyeWIvUko5clVQTVFwVk1xZG9SeDM4ZWE5NkJuOC9sRTI0aS9u?= =?utf-8?B?WldDMXIwVmJTN0pKd3JidHNWSy9zY1dFYzJKU0xDamp1RXB5OFpLNU5XK25J?= =?utf-8?B?b0dtOWRCNVlPZXc0MHRzS1JHall3NHNRT2VEZVpsZWdTdU9WOVcwWDRZelBm?= =?utf-8?B?ejRoUXIyZGxLSThqK3FpTVdTTDNBbGg5dlJxQ01kcjhFUzJrdStaSVRvOGk4?= =?utf-8?B?UFdld0JVY0NMOXNlcG1nU1ZsdHN6U29KTXNDLzVSTVVPTnBkTThwVjVYbzR1?= =?utf-8?B?YVJ3MDhSdmE5U0h0aTk2VHVJL1hzT3N3QnRpU2R3bnhIYThnOHBYZmJoV1dI?= =?utf-8?B?SWlDWmhSTUNkTi8yRFhvZHNuYlQyMDJTcnNub0Npb21Gdnk3a0hlRDF3bUND?= =?utf-8?B?SjgvbjRPL28zZVZTcVZJVm1sUHp5cG9ERlJleUEwTE8rRm9jSE5TdUNkU3Nl?= =?utf-8?B?ZzczbjQ3R1hUTGVVV2orclcwMmY3bUJsRmFYc0w2akpyNmdJQ0h0SnN4eVZW?= =?utf-8?B?NThzdzhrUlpKOXU5NUlBWkQySHdoTVpUeDhRckhaNGUxNFZQbFQrYWZjTnY2?= =?utf-8?B?em1ObWRxSWVKUUdacGFiSi9ORjVmTVZlNklGRGhSUlN4NXdPalJKTkthU2d4?= =?utf-8?B?SHIrbHlqS1oyanJLb0JFOWMzS2VVVkgxQU1hWXZKQlMxMVZ1djBTQWUyaUVz?= =?utf-8?B?eWYrc1dJTGY3ekloQUs0VjRrUCs5emlLa0JZeUdpRG5SV0FnUFVuNkRueFl3?= =?utf-8?B?d2dwSTVMTW9HNitDTityUng0MFl1OEF6NzZPVjFodmU1ZHZKalNNQmZ6ZFpz?= =?utf-8?B?TUxCYkszWXF5a2FDUi9FZnpTVUJJci9weXAvTXN1ZG5VK2dvNXVPV2JBUVBP?= =?utf-8?B?NVE0bzdjYWo4SG9yaXdVeEtuK0tWOEZLaVRWcCt4aVBDZStTVHdVMnpsczVT?= =?utf-8?B?TGRndzkxRmh4TGtZTG83aU1YTWZBbURNSWp6eXJJNjQzcFM4NEIvVjNBOHZ5?= =?utf-8?Q?SJV9XrR/aoTnuoddFBuMJSCCTHGE4IRliLbk=3D?= X-Forefront-PRVS: 0353563E2B X-Forefront-Antispam-Report: SFV:NSPM;SFS:(10019020)(4630300001)(6049001)(6009001)(39410400002)(39850400002)(39450400003)(39860400002)(39400400002)(39840400002)(24454002)(377454003)(4001350100001)(8676002)(65826007)(478600001)(81166006)(6666003)(305945005)(110136004)(50466002)(38730400002)(23676002)(93886004)(230700001)(6246003)(189998001)(64126003)(54356999)(50986999)(76176999)(6486002)(6116002)(7736002)(2906002)(83506001)(25786009)(3846002)(77096006)(54906002)(66066001)(65956001)(65806001)(31696002)(8666007)(229853002)(117156002)(31686004)(33646002)(86362001)(53546010)(42186005)(2950100002)(6916009)(47776003)(53936002)(4326008)(5660300001)(36756003);DIR:OUT;SFP:1102;SCL:1;SRVR:DF4PR84MB0075;H:[192.168.1.9];FPR:;SPF:None;MLV:sfv;LANG:en; X-Microsoft-Exchange-Diagnostics: =?utf-8?B?MTtERjRQUjg0TUIwMDc1OzIzOlpBZjlKK1U3SEpuaTJyM1hzYVVibDlqY1BK?= =?utf-8?B?WG1ldC9xam0vRWpoT1QydGtuL0p4ekdEZG1jR1JNTnUyc2U1cnVKbGZ4SGRF?= =?utf-8?B?M3VSZ2VxRkRSa3R0MFJ3R0M3cHlvQW9QK0pkQXNiVzlGV1pTRkwwUGdPcnFT?= =?utf-8?B?dm1pR25nYy9uWTRYNS9wckpXV3ZiQXluaUhITS9qVXNaZzFXSVo0MDFtZnFL?= =?utf-8?B?RGUyY0tWQmxqY3gycUxVc2IydzlTUitPL05CMGVVcHJFcUw0aGROTU4xM2dO?= =?utf-8?B?cjV6cG9TbVZUT01yVmVmVnUzck80ZkpseE5SZFFUWjIwTG05S0xEUTZ2dUpQ?= =?utf-8?B?c3paT1pRUkprOWZ5QTBVTDdHKzZOcmVsQTkrRWxrWUdIRDh5S25yK2czRFR3?= =?utf-8?B?QU1ST3NWdnp1bEtKWmtpdEFGWlBvTWE1bUdDMUE2Nk9BMFY0dTZDQVVhVEht?= =?utf-8?B?bEtBdWJUT2dBa3BJMmRtd09xcHFMWlZDWWpqYlQzaWFvU1c2WVZ4dDd2OFpa?= =?utf-8?B?dEd0L05NVFprbDRnb0tHajM3dWZxdzYwOTB6dHFkaFRqTGpBcVhVeHVBMm45?= =?utf-8?B?NWk0VGRxWUtyNWUrUW1FTFFjZ21tbXVuUFl4b0VTSlQzdGJtb3BLT0F1bmkv?= =?utf-8?B?Y25NNTJMMVJod3UwS1hhYXBrQzFkbHowVDlFWEw5REQ0UGdkYktjWWlpb0Nr?= =?utf-8?B?Rnp5N0NEQWFzTk9UL1hPc21EQ1o5T0RYKytVTlp6M3BoY1FicHMyN1pHb0J1?= =?utf-8?B?THpIN2pUVHE2YnJoTkd4WmtCdTVjQjA3OVFLMUROSEhycnYzZVV6MjJtb1VM?= =?utf-8?B?MmtJMndSMUM1d2ZMOUJrWWMwdEpRWVBpOC9KSC9OdnNyN1V0VDJpaUJUdlFE?= =?utf-8?B?ZTdVYkJxQmozZVNXdnN5RFdVc2oyOWhpeHJHOUJRei9WdzJKWVRqSU1adlhs?= =?utf-8?B?bUNVTEloWXU1MG9aWHM2dFlKNFZ1RjlKSkN0b2MwTXQvUTlzUFgwU0RtNUF5?= =?utf-8?B?UGY1cHRmZnNYSmRycUNWd3lvZHBTaWEvcUdWMmVxTTNKYzFqS0w3ZEZ3aTVC?= =?utf-8?B?dzNjVXp2TmlLWWlZQk9EZDlVZysrdUtPRllSMkptTlNna05td3RQMVorWksy?= =?utf-8?B?L0RxV2JtQVFQbWxuNkxEMEVSeSsrU2lvTGtkMTZlSmVJWTREVENwQnlxdWRU?= =?utf-8?B?MHY4VlZGZDgrcEJlVW91dTV4RTJzNnYyVW11ZXFjR3ZWeFBOdzVQT0g2c1V0?= =?utf-8?B?ZTk0Mkx1QitrMk1GRTBva3UyT01Qalp1bE9qM3ZCNUYxbjNtVWZDQzQxYjZx?= =?utf-8?B?dmlHaTI5QUQ3clFkdTZzd1V4c09VY0dYVG9SNWhDeWV3cVgwZHFCcml2Mnow?= =?utf-8?B?Wk00RzRyclVtK1JTTVp0WlIzeGQ0djF6ek5xaGN4U3NvRHU0MGZXcXZTdTFp?= =?utf-8?B?WGhJMTJHUlNxL2duUlJaNktBSWxKbFpYZVlydndTb2s4b1djSmJ3amZCeGVC?= =?utf-8?B?cWV6ZVgzbDJuTmx3c1BuMXQrdUMvYmtXMEdYOXhJMnY5QzYxN1F6RzI4WEx0?= =?utf-8?B?UzVZUnFrNktPcEpUcXNxYURkRVlHaFA5VU5yQTRKWVhaYjQxZDVQaFFMTWcx?= =?utf-8?B?VTJxZm1FS2o5N3VHRXFJZFgySkUzQXpYd1FQYU1STUs2YUg1Q1dGRXFvak1G?= =?utf-8?B?cllpMjlqMVJPQi9vUnZTOGlRay9RZkR5WlJWVHhrZzVBUHBVS3NtK3FGZ05Z?= =?utf-8?B?THpVdkkxU0l0OEdGUit1Y0JZZEdST0FpbGIvcnJYSFRjMG5BTVpoMTdiL1BY?= =?utf-8?B?b240aUF6UmllWmMrQWE5cVg4OXFqdlZHbVliUWtrL0hiUXZFMEs3dG1iNE0y?= =?utf-8?B?d2tIc2s3RFErYU9DOExjaENub0VTVytZZVd2NHRkcGlxOCt4RXdxSDdURWVP?= =?utf-8?B?bFpKNkpEQjN3PT0=?= X-Microsoft-Exchange-Diagnostics: =?utf-8?B?MTtERjRQUjg0TUIwMDc1OzY6dFpWSVVMVjBUblhwQ3VQOUNCNTRwd2RGZHhv?= =?utf-8?B?T3V3NWszbFZHVkd4dzFUSHhTVkF0eUluUDVseW9tM0RRNTdHWnExK0RpWTdm?= =?utf-8?B?ZGpnMlM2amI5dG9HMFNSRXVoNWVDcGhTYWUzZ2MxWGdxYmJyV0NCb1g0VVZu?= =?utf-8?B?RlB4ZURnaVRzOXc2WDN3Nyt4cVpYTUUxQlVFUkNDZ3BZTVc3YkdSNUlhR0FI?= =?utf-8?B?VkpYUWN2OGJqcEJudDF3aUJzY1JveFBCcmp0MGdCci9BOFBrZUVhb3Z6ZUIv?= =?utf-8?B?MFhiSmh5emV1RnhQOGJqeEwvNjV3UndaeXhXUW5QZHFINzgrbS9EeVozSHBx?= =?utf-8?B?VWpzZmN5SUdxNzFnRUZ6bWhjdzlsdVBoa2g3NVJicWZpZkF0U1U3Q1d1QVpE?= =?utf-8?B?SUk3T0JWTVpwcGw2MFBFWWtlWmpVMWVaaGlkaEZLYlcyRVBuQytCNWtYVVdl?= =?utf-8?B?amZHQk9RWndCSmlSZm03K0NJaXdkZUxHOEJRRmNIVjBVazhlUmtWaVlXSy85?= =?utf-8?B?Y1A3V2crSyt6QSs1NUtRcmJnblpoa1loQ0MrWlV2RE1Xc2Jvem91eVBzVFZ6?= =?utf-8?B?ZDBvS3FlQ2M5bFB2eDF4Rm9GQWJIRzcwc1Faa3Q1OFFQdENDLzFTUFdaekpG?= =?utf-8?B?RndsRVBra1RzbTBpU2xyNndlVTd0dG1rK1FxTmRDMitUN0cxcW5YNlh1NUlH?= =?utf-8?B?eGpLOFRmVmZWbU5oQVJCc2RQS3NRalg3OCtqcHQ4ekVJQzJmV3B5R2hDYXAw?= =?utf-8?B?d2FvaUh2dVY3dXdvLzN5UjIwTFFzWmJwY1ZjYUVOR2dmYlBobmd2S1RWb1M1?= =?utf-8?B?Y0lsZmR6OGNwNUV1SWlucnRvbDA5VlYvQ1NJNE94cXFQOGVKb0QydGNSUlJ4?= =?utf-8?B?NXRJZDh4NXBUL3l2S1ovQ3JXUmxCVW1CbFJtRkNQV2pvdDNJNCtiMzgzbTlN?= =?utf-8?B?b1VUVjJZR3FDN01hU29TMThNWWlzc2VkWG9Ud2N3dnNpaitpb1RnOGxxcWNV?= =?utf-8?B?M3lFcVpITytRdERVa3ZOREdrRzVORzJYZ1ZkRXluR1VGUDdIb094aGxkZ09p?= =?utf-8?B?Znl5R293cmpJNXRrS24rVWMzNTR2eWc3QnZnYkNIczZBRmpYc1BXZWNWNXdp?= =?utf-8?B?QUFaT1hRMWJwbExOTHFISUd3aE1CVXQxMGw5T2xDMDI1QkRmQ0FyMVgvSkxX?= =?utf-8?B?aXZuV1NQemhsSHJJOTNjQW8xYzN3cG14TFF0RHd0V1FGRzQrY1MxSG1XQTZY?= =?utf-8?B?Q3REcm5TdDdrWE9rY3F0Q3Y4aERIUCtiQ0t4N1ZvSXpNdGF6K1V4NTVrRzZU?= =?utf-8?B?WXFsZHdNTHV0bXloU3JhMlhSVTY5elZjT1hiQ2dJVy9EMytlc1hJMjN4Tzk5?= =?utf-8?Q?zz68s82?= X-Microsoft-Exchange-Diagnostics: 1;DF4PR84MB0075;5: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;24:BKhWPhc17ywhMG5mau7LaaK4v6y2WVbx3MkoPQYdmIUA6I3oNgxAKEBZR2k6c3jYYRrS+IXQ3N4YxSZKOD17MhAduUXpb9UHqV7apUp7714= SpamDiagnosticOutput: 1:99 SpamDiagnosticMetadata: NSPM X-Microsoft-Exchange-Diagnostics: 1;DF4PR84MB0075;7: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 X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Jun 2017 22:49:56.0947 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-Transport-CrossTenantHeadersStamped: DF4PR84MB0075 X-OriginatorOrg: hpe.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/29/2017 6:43 PM, Dan Williams wrote: > On Thu, Jun 29, 2017 at 3:35 PM, Linda Knippers wrote: >> On 06/29/2017 06:28 PM, Dan Williams wrote: >>> On Thu, Jun 29, 2017 at 3:12 PM, Linda Knippers wrote: >>> [..] >>>>> The /dev/pmem >>>>> device name just tells you that your block device is hosted by a >>>>> driver that knows how to handle persistent memory constraints, but any >>>>> other details about the nature of the address range need to come from >>>>> other sources of information, and potentially information sources that >>>>> the kernel does not know about. >>>> >>>> >>>> I'm asking about the other source of information in this specific case >>>> where we're exposing pmem devices that will never ever be persistent. >>>> Before we add these devices, I think we should be able to tell the user >>>> how they can know the properties of the underlying device. >>> >>> The only way I can think to indicate this is with a platform + device >>> whitelist in a tool like ndctl. Where the tool says "yes, these >>> xyz-vendor DIMMs on this abc-vendor platform with this 123-version >>> BIOS" is a known good persistent configuration. >> >> Doesn't the kernel know that something will never ever be persistent >> because the NFIT type says NFIT_SPA_VDISK, NFIT_SPA_VCD, or NFIT_SPA_VOLATILE? >> That's the case I'm asking about here. In this patch, you're adding support >> for creating /dev/pmem devices for those address ranges. My question is >> how the admin/user knows that those devices will never ever be persistent. > > The parent region of the namespace will have a 'volatile' type: > > # cat /sys/bus/nd/devices/region0/devtype > nd_volatile If all I know is the /dev/pmem device name, how do I find that? -- ljk > >> I don't think we need ndctl to know which vendors' hardware/firmware >> actually works as advertised. > > Certification stickers is what I was thinking, but I was missing your > direction question. >