From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.14]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A5FB3207A20; Tue, 15 Apr 2025 17:46:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=198.175.65.14 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744739181; cv=fail; b=HIC8BhWBxHFyMnX6MKuxMdssX/euGHE8Us7r0j8RwFltGVxQ+3Y2P7WG4obi3wL9D86jCprEnAPqF9PzPv0GC/NrYFMb9eLfN+sBRrqJ0811fTmIjTC04tLapVMsa6G7mtlm8EtQwxKWp2DTU2Z23DlStsJn2DJsI/HHNY2QNIA= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744739181; c=relaxed/simple; bh=6Fb8GKkt+r5Qzsn4zZ/knnLkjxVpiI3/4uTG79Bkxi0=; h=Date:From:To:CC:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=m6pbjMfTlZUKbsXjBuSLL6lg4FrnI8IRUNVngx2zjdT8TINLZwYuMqs7iWIKLSoLu8FTjw2Pu5Tp79lhscNRjJ9+4NedqPKBzydTEoDYLl+s3JMwKNRNYNNZikOGGsu1Vjla/uQ4AzvMFU/MpWFZ10YXDGZ3wX9uQHhSsQlaaGM= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=PbxCM7Qh; arc=fail smtp.client-ip=198.175.65.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="PbxCM7Qh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1744739180; x=1776275180; h=date:from:to:cc:subject:message-id:references: in-reply-to:mime-version; bh=6Fb8GKkt+r5Qzsn4zZ/knnLkjxVpiI3/4uTG79Bkxi0=; b=PbxCM7QhtpyFblB5GJQLRQsS1ieQV6YSnQ42tMruyfyfKxNIZ0ALR9EI KEpHs6HdwOq0QKEIuDoi5qSbzeMUzP69spg0TJutDgfFliReRfKxnzJjP sSKst//6hUaLo55xG59tmma7Xa54XmAk+/UW66r0F6IuoJSsibZzT45tR xkb+9ZqyK0D2+ffkoNT9K6hqctybsvDd8CJyzt5ZE2p7KPw2mctZWhETA aM273jnmVjN4Cxcvef40M4o5MonvFvlYMu0TgEo8bWkl6+rO4Sf8+krEP XEbLy1Yea79gBMWX33f5M2NJd3dgqc0eZ5lpmRW5JDb2w3O3n8uHPKdeX g==; X-CSE-ConnectionGUID: XEam9ToqTfK7E0NI9plCPQ== X-CSE-MsgGUID: Jz7m2vgAQeykFA4McCD9dg== X-IronPort-AV: E=McAfee;i="6700,10204,11404"; a="50063336" X-IronPort-AV: E=Sophos;i="6.15,213,1739865600"; d="scan'208";a="50063336" Received: from orviesa008.jf.intel.com ([10.64.159.148]) by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Apr 2025 10:46:17 -0700 X-CSE-ConnectionGUID: KbnyzoRNSweNoh2KINO9LA== X-CSE-MsgGUID: pDC+iicbSnCFF6sNtTYPPQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.15,213,1739865600"; d="scan'208";a="131171735" Received: from orsmsx901.amr.corp.intel.com ([10.22.229.23]) by orviesa008.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Apr 2025 10:46:17 -0700 Received: from ORSMSX901.amr.corp.intel.com (10.22.229.23) by ORSMSX901.amr.corp.intel.com (10.22.229.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.14; Tue, 15 Apr 2025 10:46:16 -0700 Received: from orsedg603.ED.cps.intel.com (10.7.248.4) by ORSMSX901.amr.corp.intel.com (10.22.229.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.14 via Frontend Transport; Tue, 15 Apr 2025 10:46:16 -0700 Received: from NAM10-BN7-obe.outbound.protection.outlook.com (104.47.70.41) by edgegateway.intel.com (134.134.137.100) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.44; Tue, 15 Apr 2025 10:46:14 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=nbj1L0oZVSzPUMWICCzvPV0uSs3GJApw4jMv5pJjTFRaNUd+TYdB40B6oUUwcEpdBO9H8McssdTHdL5M5bKwjIPlvn1V2mWT4hYcJys3IAjT8MAgOQIvUP+UExpu+KPxJwo2f1jQTysmUS0Vxn/uUexHK2OJvVJi/1uYXme0wEWADFsoAD/59cY9/DQNBI5PZhtmNwIepUgtS40mKnPKk1jjDL4857C+6H5FjvxVxZog2Es/qocd6JHeXUOkXpQ+KCqosfGS9HqJs0V1ljzwQlYGEjw3sRFrpWPZMoHfCoCyeAZU9Hsh6ZqzNPOCujHkY86jC0silizlYW3eEsvhyg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=/saO1+V9fK3KMf3Fjwo3WAsXPP3I69CrznbKg4q8w88=; b=kZ3mpQ9OWQSJ4Elw1vUGVfHlSOvatJdQXqs5toD5q5bIceunwv9DY+bL3VjflSxYtluXaQugpIlx2sOROVC2gIfl4JPu6Te5kDEUUicWeDeZyBUvPHAYOUypywWSwLzLQNm+PUyYWf17DLlliKqoRPDBcUtoQezshtHRTgqrcmv4pUWQJt+mLw9TtEWXg3sm82e7LrBX4HeyvjVjC+RKmyM0LxvE53R1E83XiNUsD1JwK+Hg4sVrffw0QIMy0n+jDUcdS4rPMvQy/WKvNjsZ8+vWNQEY/E6MNiV1scmAqarmMO6EumZfb7eV6qEGPQKaxzdclvGTSwQqayUCG5Bzmg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=intel.com; Received: from PH8PR11MB8107.namprd11.prod.outlook.com (2603:10b6:510:256::6) by CY8PR11MB7012.namprd11.prod.outlook.com (2603:10b6:930:54::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8632.32; Tue, 15 Apr 2025 17:45:44 +0000 Received: from PH8PR11MB8107.namprd11.prod.outlook.com ([fe80::6b05:74cf:a304:ecd8]) by PH8PR11MB8107.namprd11.prod.outlook.com ([fe80::6b05:74cf:a304:ecd8%4]) with mapi id 15.20.8632.030; Tue, 15 Apr 2025 17:45:44 +0000 Date: Tue, 15 Apr 2025 10:45:40 -0700 From: Dan Williams To: Jonathan Cameron , Dan Williams CC: Ira Weiny , Dave Jiang , Fan Ni , Davidlohr Bueso , Alison Schofield , Vishal Verma , , , , Li Ming Subject: Re: [PATCH v9 00/19] DCD: Add support for Dynamic Capacity Devices (DCD) Message-ID: <67fe9b44b7663_71fe2947b@dwillia2-xfh.jf.intel.com.notmuch> References: <20250413-dcd-type2-upstream-v9-0-1d4911a0b365@intel.com> <20250414174757.00000fea@huawei.com> <67fde59784933_71fe2945a@dwillia2-xfh.jf.intel.com.notmuch> <20250415110350.00006eee@huawei.com> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20250415110350.00006eee@huawei.com> X-ClientProxiedBy: MW4PR03CA0128.namprd03.prod.outlook.com (2603:10b6:303:8c::13) To PH8PR11MB8107.namprd11.prod.outlook.com (2603:10b6:510:256::6) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH8PR11MB8107:EE_|CY8PR11MB7012:EE_ X-MS-Office365-Filtering-Correlation-Id: 524306bb-0963-440e-c764-08dd7c45590c X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|376014|366016; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?levQXiVujEETTa5ltQHUvu5SopbkA4JZ0BtVW/vQk6c2XsX9LFnXQfnEef8n?= =?us-ascii?Q?+Jd/j14fIzyQdaPYBTV2T0L+1kaReoCgL44NHEu7l4CqqXvlcSlTG20ewWq3?= =?us-ascii?Q?SIS/A8G6ceM4589I82pPKl6PPhtWd0OpJZnI9NCGnYyI0O7nXBpA1GnapV2q?= =?us-ascii?Q?u8s2qZzMjFASJlJCL3LaGwlwkOU8PksF49xEkKrBCnDyn2LIRXKVW48roYRM?= =?us-ascii?Q?Ue9x9iEIYiJxbZ03gLIi5GnHZIjOnviZNgi1B4wHGRsqx2RhCVtSuwXXDvT0?= =?us-ascii?Q?ddgUsWLtU5vmk4gH2rrt3rz4iXZbAMB8/lnBEHCC8zCEJmz1HIZb6zmyeVf7?= =?us-ascii?Q?Fp2lMGjb15ykwnjmdd5oAYJXYU4QRPVSgW3HHwP2K1Q1T+ZQB85CFQrmjIIa?= =?us-ascii?Q?k/w+8QA3gI9docEcGtsnHpZ//b7PQzItqBzG7A78361aguc6Ybo5ilbScsnH?= =?us-ascii?Q?uu4L8vmVc9k7b959nhQ3RA1S5hM+0BPryh6jrvDFJFWSgRxiZ3aasLAuaHqf?= =?us-ascii?Q?nhcsKSXhvDdDjBxteRmV36M4/YK/l3tbqkYy1WcW/rfRKwGkLXpY0H2lcqy7?= =?us-ascii?Q?CfObLIfxjHIPjJUBbaZO3cl+Won0+J6iY6bfROaalEmF8XE69a34C3nDR3AJ?= =?us-ascii?Q?UeclKprwfnZdM0T95ifYjfs3BTuFI9Eb95vYR8Jcl2TpNI3y+SP13CBX9Tqd?= =?us-ascii?Q?vhWdueX0SK4Gwf2ehWGG4n5QccUCrbeMCPsx3t8PspvFPbavPfaNYBM1e9zs?= =?us-ascii?Q?RqpTvwbtjxgj/2S9Evz1jetK+TZ9afWnVihzWVMuE3HeQ3vOMlkMbbW4Xc79?= =?us-ascii?Q?XpjUA6rYKQ8d0l9xS8psysDHWL5PA6wSXhCS0rxNtnwKemxW9XhOCVqS1K4T?= =?us-ascii?Q?unKgATJ5I4FKnSVfWttH3GSzqHgTR9Isy3wNpF5xf6nFuI5x4+jHnfM1myJ7?= =?us-ascii?Q?OszHKtgykydKzE/UjVIrOFYzRgmKhgwGN/T0zEHy+ycI4HF4qGr9hwAex1cT?= =?us-ascii?Q?ijEr2TwDJJEV8LfN1iqiSm9I45EjzX712cCle2en5gMFvxktBSJIktLv7h+r?= =?us-ascii?Q?sN9CzbPpsGHpvhLOVIYfMxI4DGXtbBdofDtn//wnVQ2btUhU3qI3uNKoMDLA?= =?us-ascii?Q?2m0j8i1zPGcWTU/y+cPt5WwV6QOpHSLgdJ0q84ib+/FKIS/FqhFNBx8Ldi6h?= =?us-ascii?Q?LO/Ru98/+ZQIFD9MOChIBnTqn+4J3SbOS/EFLSwmQURWwZ8Y53NfHFCjO0j+?= =?us-ascii?Q?YuUGovw4wsGvLXSy1Ga+TBy4BcLcAzscaoR34fMVpEa7XpzmlJ07eyjOWgPp?= =?us-ascii?Q?ErY5nnICvQITZmfbyMFZYSuPVtcmnt7/hq/DhK1Waz/EVRVielfi9nUQ18C+?= =?us-ascii?Q?LaoJE3TobRF8ordiA8qYdO20Bwd6+sDb0t6IqbrwObq7NxHhWMX7WPNYr3hx?= =?us-ascii?Q?2ztI8Lc2088=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH8PR11MB8107.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(376014)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?bgxcq214qDMxfc2XDIQkCPEnSB7ZIJrz/ZLqHKPs7sElOcKFvAbypiWO1PDE?= =?us-ascii?Q?F/SQC4YGoMFQHbeu0iMUh5ypsYlcS/wwv3Ctxu2ndFMcYLmdVVi/2upFQtrX?= =?us-ascii?Q?myYbQysouCjvF9dlOlNVqLQdBz6cSA9fzmw19KBZesrzWvFxLhoOkm+kSdZJ?= =?us-ascii?Q?xC+UnL68dpdVwNt4ttF1sS1uzQSuHyclccigfZk+FFD3lBahGG1/UBUJeLVm?= =?us-ascii?Q?YISqgIOq46mAekhqL8U/aWiPf484tgZsJQbKPPm4vg2TUJtkiDg7UvPJRjGe?= =?us-ascii?Q?X9t9MNoKi9/J3puU+C/nRdi26aVJJ6ml6ad59Q//EDS+5dsS6L4+UnI1veHl?= =?us-ascii?Q?P/PT86hLpztQLuLkSGJV4wIafENV8k8NtLrkSgA3ZzSO6AtYDotiQW0VeC5G?= =?us-ascii?Q?zWv/q2Fbj4LqfMSL9D3IU2KXU1r12e3KDQIReG42Ixx0rPfnVdRdtX7VK22H?= =?us-ascii?Q?hI1zLKPPFVRgzfeB1fqvlP6TMNokqh+mhzzDixwitKhNGohUEccdap4sja8+?= =?us-ascii?Q?jmXh6dGC8T2PtCDyuGxzRY5ThEdZzB6AEuOO7TdoKmwIk48Ueo8txKKKIkMg?= =?us-ascii?Q?UFeLHwleXokiA6CKk8EB6I9eUN6i28eNufRftxa4jWcPepiNe1e4nDGWUe2f?= =?us-ascii?Q?sZ2HxEuC4epSym+Wmh4uD5pDeHVqeQxa6m+f8EgBCd6rgnromve8xVEDQAYR?= =?us-ascii?Q?0gv8oqYa2xQf7VcXr17N7TSSFSoRH5utyrCUEEB7ER78c2RRVSRWbyZZM3QW?= =?us-ascii?Q?uNADROQQ7ryW0XzS2eKYCfml0Vovi9cVDQaa/hzqYAtd3obhmeLn9Nd+3wkw?= =?us-ascii?Q?xTrohZqq/uhpGmmLzJDnUNTSmcV2WKmc5CsInsJBbDODlSKY1l2ONUK7XcRY?= =?us-ascii?Q?kizxUjGm/5TUs5M3Qjvl9rfVGwtualFANUoUBMpbcru8tT7rNTm75Vu841q0?= =?us-ascii?Q?a6XWn5+Db8RwRYH9cuNV8KP8O0t4R0F3OVatd3mKdWbCFXXWKrA62gWTcy2d?= =?us-ascii?Q?8bgmScNBdeiQdgeJqDC8t7GE1+BYRIg79avSJlFalRIf86TS+HwTCnrQGByk?= =?us-ascii?Q?LSltJqyvuGqrJbv3BiDnkJuqejrqMgkq1+ct3FyxP5Mvqwn/diZs0BuJJga0?= =?us-ascii?Q?gAj5tVBdQxsRdATPuQEVhDwOCcWa/RWoOrh3bmtzveYIp8NWPnMfXxmKvNpq?= =?us-ascii?Q?y2zKw0doNT1QLdJVNbd06np/WANQmePjG1teoVavy1K8EcwCRIobB6Vp8XtG?= =?us-ascii?Q?Lhxm2Y6gQrq2qGBHT5ARiFFtYYkM5X271V63X6+B/nmIr/+MfYA8u+RvMttL?= =?us-ascii?Q?mgNfShwC2UyXJW4TCh/DSU5CCexU5lkqqENxSOX+tMLh8R8SSf+2O3fF+srC?= =?us-ascii?Q?DG++coPbUp+o9kO5fMqOYNTSMiIT8Ti0X1n/4KSLmpuExk6slhY4krrxptX2?= =?us-ascii?Q?PcfvaO1mqig2e+CWyIxgAXJa1bkZoYG2k9SqCj3e4AautwZS5SVoLnd29Sxb?= =?us-ascii?Q?itwLpfTUXCh8xjZvEKt9UYT1Mq7fNTb4hVhoDrwpluSw1umSONr9Z144UYHZ?= =?us-ascii?Q?HKBEQ+wgOp7A4hFh1B8PfnKpO2WGV9KFWYrNuZknz+JoTjLsWdZ/CeRY+nQe?= =?us-ascii?Q?uA=3D=3D?= X-MS-Exchange-CrossTenant-Network-Message-Id: 524306bb-0963-440e-c764-08dd7c45590c X-MS-Exchange-CrossTenant-AuthSource: PH8PR11MB8107.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 15 Apr 2025 17:45:44.6532 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: l1XlkfBhuZEfid6QL/v9MViOjo45KgXesPvzhRIeows2++9Pl8l1V7bVqGym0yMIAN7NHMVttkV/8TJdlf1dJw/LOMSpgrIPtrRB64g/egI= X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY8PR11MB7012 X-OriginatorOrg: intel.com Jonathan Cameron wrote: > On Mon, 14 Apr 2025 21:50:31 -0700 > Dan Williams wrote: > > > Jonathan Cameron wrote: > > [..] > > > To me we don't need to answer the question of whether we fully understand > > > requirements, or whether this support covers them, but rather to ask > > > if anyone has requirements that are not sensible to satisfy with additional > > > work building on this? > > > > Wearing only my upstream kernel development hat, the question for > > merging is "what is the end user visible impact of merging this?". As > > long as DCD remains in proof-of-concept mode then leave the code out of > > tree until it is ready to graduate past that point. > > Hi Dan, > > Seems like we'll have to disagree on this. The only thing I can > therefore do is help to keep this patch set in a 'ready to go' state. > > I would ask that people review it with that in mind so that we can > merge it the day someone is willing to announce a product which > is a lot more about marketing decisions than anything technical. > Note that will be far too late for distro cycles so distro folk > may have to pick up the fork (which they will hate). This is overstated. Distros say "no" to supporting even *shipping* hardware when there is insufficient customer pull through. If none of the distros' customers can get their hands on DCD hardware that contraindicates merge and distro intercept decisions. > Hopefully that 'fork' will provide a base on which we can build > the next set of key features. They are only key features when the adoption approaches inevitability. The LSF/MM discussions around the ongoing challenges of managing disparate performance memory pools still has me uneasy about whether Linux yet has the right ABI in hand for dedicated-memory. What folks seems to want is an anon-only memory provider that does not ever leak into kernel allocations, and optionally a filesystem abstraction to provide file backed allocation of dedicate memory. What they do not want is to teach their applications anything beyond "malloc()" for anon. [..] > That is (at least partly) because the ecosystem for those was initially BIOS > only. That's not true for DCD. So people built devices on basis they didn't > need any kernel support. Lots of disadvantages to that but it's what happened. > As a side note, I'd much rather that path had never been there as it is > continuing to make a mess for Gregory and others. The mess is driven by insufficient communication between platform firmware implementations and Linux expectations. That is a tractable problem.