From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM04-DM6-obe.outbound.protection.outlook.com (mail-dm6nam04on2079.outbound.protection.outlook.com [40.107.102.79]) (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 2D7BA4A1E for ; Mon, 8 Sep 2025 18:18:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.102.79 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757355503; cv=fail; b=R6uK491c4TqmkAryKBx19geKNhQZf/aQoaPueREchP86XN7afHXeAOkqTWB6wtIKxiQscGdOF4zJzTy8zqhU42z1762Rl3ukusA9qTrm9FJmeSBo0OuBzsrqRaIE8qCrTy6zexeb19LwH2FggYehbK9ICP2lhInKINgzllpvnoQ= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757355503; c=relaxed/simple; bh=ovbBUOIBtW23o3iP4lx2aRD3pMpyULOKBz0lWlgp3LQ=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=bm+CdLhsZHvbrMd1j54N9h2JJFYgNTxT+39SRzp38UwSTwi98Z7ORk39dm3riHtvPHRregpvjur0eI2ZGUWbEBB54gYG0f6euUxQ16iX1y6/AzJhHy0s3TTolqYrzAj2k2CyftJ4FJiMkb9C6V6oCkZXo+JtfflOGOaBW9GM4vE= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=acV0Sq8Y; arc=fail smtp.client-ip=40.107.102.79 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="acV0Sq8Y" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=qJWYD3hjZDW+nIO0hO0QzugoRV4eZlt6IzRuItEPScSmlFtiMW6pocxidF+yFm4DI8ZbGh9veQk01B1qUwQ+D0AM1o8537Mor/7Zu0uCP3dPmv9k6eKKLj2xRUZgaoiADjeCmp9OeuJwDmhO9OPy7bYU/0x7lguF1r/fhyZmScLR4TNqsfexCSrZ9Zx9SGXfzO6beHYNx4QRnLPquwGn8yv7Lbpo6X/6P/We3NIR+qJU6pLYuSo6Do638tbMOtxAuI1cnAMbKXoiTs4Tz7tyt9mxe9y59nU67zqU3K1LStfa97rusvbfRQL6y66p4UAa39UQsSPoE07hKYR6Lo2OCQ== 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=mTazilRRQUgzVgW6twbcGUfVNxS0a3YnsG2oe8K77sc=; b=MEkjWac0KUV2zWcuYt4/2ng2FIiSk1cVSPz51LLYEZ3qYWLFYEo61yhLMYQx5JHgPe7DLIPheIzHxbTqR7XQyV2YTdFPE0xTR/JEfpBDubxITP+6Unv1JB1gpgaF/DaXecc1W8bzXZsHhkKcD38QkosnuzB0KzKkw/8XAjD1yppwBQObwGVwBY350xWEYtMi4JA4NixgS4fpWcyleJEzGIf/VfeHcf+PB1ZTj28BMLCum+DqfjkgE7nkNKk8VxhRNQmwXJk2Ujz1bY4eboXebwa2lPEvcvFe3l/NAgTRo0icC+dcoWvcmzIdcwD/JUkV6n4RDsKLvrqydD5vYaIwvw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=mTazilRRQUgzVgW6twbcGUfVNxS0a3YnsG2oe8K77sc=; b=acV0Sq8YdBQjyb8nHQiuPYuWav8jRbHuwHKgAdAhhr2KvFeCjAv8TP5pwswL/l9g3PsuUC/0PnftJQMknZWLFS+ckza/TP7FH7veWG/lPqf4L75N7Bcl3peceEtURgRj22HTtMhRDItYdLL6VPa8AP+WVcDdKEt8HqR3G8oyZR9iV83tVpC2Ma8jjpz1f4jfQCLk8d+H9cABUlZQZeBxDmmuwLmuRfFChjQ1nICcHD6BiRH8tdMBbmt8nE2bLyF6aERZkhCcQt+JcqXiwZMTDOWESAdOIG6ExtVHJL8KrAIInMvKJqwlEnjcwlI6OpA1NGnQKal0YbigHvc1D+K2nQ== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from BL1PR12MB5753.namprd12.prod.outlook.com (2603:10b6:208:390::15) by SN7PR12MB7276.namprd12.prod.outlook.com (2603:10b6:806:2af::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9094.22; Mon, 8 Sep 2025 18:18:18 +0000 Received: from BL1PR12MB5753.namprd12.prod.outlook.com ([fe80::81e6:908a:a59b:87e2]) by BL1PR12MB5753.namprd12.prod.outlook.com ([fe80::81e6:908a:a59b:87e2%6]) with mapi id 15.20.9094.018; Mon, 8 Sep 2025 18:18:18 +0000 Date: Mon, 8 Sep 2025 15:18:17 -0300 From: Jason Gunthorpe To: Pratyush Yadav Cc: Mike Rapoport , Andrew Morton , Alexander Graf , Baoquan He , Changyuan Lyu , Chris Li , Pasha Tatashin , kexec@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 1/2] kho: add support for preserving vmalloc allocations Message-ID: <20250908181817.GG789684@nvidia.com> References: <20250908103528.2179934-1-rppt@kernel.org> <20250908103528.2179934-2-rppt@kernel.org> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: YT1PR01CA0156.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:2f::35) To BL1PR12MB5753.namprd12.prod.outlook.com (2603:10b6:208:390::15) 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: BL1PR12MB5753:EE_|SN7PR12MB7276:EE_ X-MS-Office365-Filtering-Correlation-Id: c329a428-55df-406e-c63e-08ddef0415d5 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|7416014|376014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?UtcEGsRI7GuAuR2NxPDzEu/lg+pSk5oHtRkV18CPIjlaSYef2fAsMomQlzYa?= =?us-ascii?Q?ZYwo3PtHC8eg1WAqpMdb6b2TfdFoten8siZ+CxQ+/x7loEahmuepX9N5OZi3?= =?us-ascii?Q?X9SxbbfxYNWymJejtL4gUUC08z9IrWFlU9s3oKsWTKyJ5E3mVq/HA9RQfDBU?= =?us-ascii?Q?6F6HeM6OTOweJ+wdeZ++dWCOVrnGzgJb0jUJUy2lmogP4V3QvxtI9V7m4Hx3?= =?us-ascii?Q?+0o4js0+jfMGYz9IH9MIZAntlN0NpmBexjkj2tDUGYkhVyQSwYVLmq8XCBF/?= =?us-ascii?Q?xlW34JKLPWmihJQJcDKsyW2BtgtDMbyLFbYYLYUlKnFdbJCLz0APr5auGz5l?= =?us-ascii?Q?gLASidoK4mgdYJa09d4qF2Xja3UJIzJpkSXRK86HI0gbSzLT3aWmM+ww/+vC?= =?us-ascii?Q?CgfgpdIcplAok39RTFsufIktqHy1HFWUNED7xAx5/4uV6/R+hFf/+wd8/ezN?= =?us-ascii?Q?vrf/Q1E0Ckry7VzUXzcfh/53I5+P4LDPqLAeb4JePLA/zW9j5TI4ttM2LuMO?= =?us-ascii?Q?4ttdqghHHbWu8d2KfvdflUee1qSJNzlOoYI6NjFxcOi5SEmyGoN8P/xb/zb+?= =?us-ascii?Q?iKW5Zx7aE68FenzNnAG50uddFIaSl42WmKpYK9b8zZEUNLWgKjACNsBET+9d?= =?us-ascii?Q?6zoiGXp6m9lzSfdpEivJcYgUfzxcEla8wpBhEBjyvTGTdp0FSUvGEO6j4WgQ?= =?us-ascii?Q?d5sKJPCGNQHDFkSVDIyDdXfCMxRPdZHn5sgF5ZRv3VIdkbcD9ggwrY69jyIH?= =?us-ascii?Q?HJel1/3VCoVMAmHycA0P3aA0KZ1RoLX8LOPr3oTus4+MJ5QXkk9BwAx3A1Az?= =?us-ascii?Q?KPGnFwCpnpoHJvvPWGTlHYnaHGvgn2+aK/WbXTkecPFU4ZVfO6aQkEGL+6+h?= =?us-ascii?Q?iH7MLt1lkvGKN02jh5YapFi+kgMSzrVK2Cqa7XvyU+LTg1p6EwQR0Ss3QYZ+?= =?us-ascii?Q?PzeCUEGQDpA6XPASpu/JN1VopN6iYl9P2tKrz6VkcEJBex8MNHlMbNm0vxKb?= =?us-ascii?Q?+/rs3wWWrGNDwOJj6i4Yc/QRJOHkmFQYBy8wibTnlnlP0zLNgHRG2c+mhpIf?= =?us-ascii?Q?O7LBdybWB6kbgQlZGxvXeTuxsM84SP83IkUoT7yIuPQSBY3zjlEHZ0ISnywD?= =?us-ascii?Q?Ka/CVk5o/t0C4444QtEq92jDM6xpoQV8rtcczTtEWHQvj86y1CBje1hcsQ9Y?= =?us-ascii?Q?FCJXuqowYuD5fxB8Xj/B9LnbbopB5AgGBV0GCJ1ydaqlDURgOO8ZeLd/Bbwn?= =?us-ascii?Q?dRgtkZlg+4iwfDb+vcBR+My1Argnrz02qXQRAbPwW/Ti0LTiECw1BqwStVhr?= =?us-ascii?Q?FjjYTCef3VYeuqXu/hdGP+rv6MsZgM+31Nmp+jHYu/LKDP0t0cDoz6yJ/0di?= =?us-ascii?Q?IV/Rxvv0JSt3hgsYXf+2xmUcErHZmTxPlayt1XQTAP3P109WUoDp3ZV4E4B2?= =?us-ascii?Q?ve5cgpUtBb4=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BL1PR12MB5753.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(366016)(7416014)(376014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?A2jLwsmkpKCa2vD7Tc3MicygEL4FIbDTA/H41ckRXagtav2Dk2Fmpr21Zs7M?= =?us-ascii?Q?G1i8uuCKG6jygjoToufAmjXoTawdMCswa+tDLrKp7tS4UhbdmVdTUjbNxWcx?= =?us-ascii?Q?E/cAypdiOMyZayrr9E8fDtD+mNsyOIoBkuJGHal8Emn/aywqFaLUClwpgk7H?= =?us-ascii?Q?5GtErHiTnSFkBzS2gZ0BDOBc6wPBIiTgV7ccfiJZFMRV4R7ZDi6WsGEPLEYj?= =?us-ascii?Q?DTOUqrab4RjDxVSp9mHvoXGbSTr55l3Cq6WAGJL58xfKbkmpsZ006IH77rqD?= =?us-ascii?Q?1Abluz7u2DsU2Ggge7+RySxG0gJaYYOZ0yRKO3v67Rf2Q1B3bGP0FRf+dK/L?= =?us-ascii?Q?YFwFsP7vjqgN6dbC0u0AXr6JlDpTtUK+fnyL07Lm1NWpGDArKJiuuXhK6/6c?= =?us-ascii?Q?ObVLpWSEatKmDn/L2h9Fy8RCBy7JNhdrZwDs8NatD2lywM1J9cjd0euXkkEC?= =?us-ascii?Q?3NNNNPzyFtBmW6bPNovBkfVdhOmxemm0rL62xCVIP+LL8aEe3GsutEf8AT2y?= =?us-ascii?Q?zjmJuwy3souq9KD3VQzXfSGBuhwvbbyKDl2H0vo93yBhzLR6E81RLXoIK02e?= =?us-ascii?Q?nvwOvjB3rgbJF793viGEYEVqPtWBzz9VlhJ3400yAmxBC4mVotq0cZA9KuNu?= =?us-ascii?Q?ABo4Icf5XwNN75D9EwUEh5AMvaFyCObVoBHykZBkRPjvQZsDpTlVIrYiDBfI?= =?us-ascii?Q?jktfXmcn2BCqzpNcbuEZVGiXjY213Iiisqf0izTCNhVWIbXAaNAA4LLnui3V?= =?us-ascii?Q?sW8uoIrpqy3boh5Dqhoh1Ci39zwYZPgwLxv+YPg/JoXLXuvVRzROVMvhCQwY?= =?us-ascii?Q?WbfcCbgJh+7Xu1AHJMG53HLfs2UmTCYGXfjNMsEpA+RowTmSSXSNV7YQsDt5?= =?us-ascii?Q?2xaOSdGSenoLobp5RcUZnQDesN+QIJ5mBTqieE2BQH+r/+LTFzSmWwbCpbXT?= =?us-ascii?Q?QNrDj+BsEaSyGm1jfCDDYpBHa4Zrx94MFYJldsR7XsNvGvCSYVwW5aJpxJzn?= =?us-ascii?Q?kPmgrnXuvRcf+X/3b1WRT6w8Lf5dyVSrFRexXQw/htebagkSaxk6dMrzF1rQ?= =?us-ascii?Q?Eos1ecD5koWgRco8K7OCn1vuKqR8UUMl5rV9F65utVYQ/TN44KI+l3gqAJWA?= =?us-ascii?Q?BClw0rCFdWvzblXfeszIkMhmOBGXi2piXrZ5NRj7xa2ussnK2gH0FrdASylY?= =?us-ascii?Q?W6WCW8OvAY+fwkk0POxDFMZISu9GBCvH25opzjA3+C1Jh0fbOE4xI5CsZF0s?= =?us-ascii?Q?JfzUH3baUMpc/OG9T2Tp8KE7qgcPH0PvBjrTlp41UjzHxf1HD1R/6sGy3a0H?= =?us-ascii?Q?LXV1pTgCZ2IAPEzFzeNKKM6RCkSWCjkF3OjBvI74NyWljWSgbTjJvLPd3BHX?= =?us-ascii?Q?P42SAadQGaCMLnQSEMzlSTlPNgadbR5iwWjilY9i0o1OK+H7X7BSqftv/AUQ?= =?us-ascii?Q?sg+ZPi+BZvfpCVjOyzYyAOIAXyWHanlizu5JWctiKzhO2FBBTn8zXA5zuaoM?= =?us-ascii?Q?vPRXC2a+xL7PbmeP+VZtgmTIDjw5ityEEUCJDUR2c3ZjAzXWC2/l4qza0YbG?= =?us-ascii?Q?RUqd9wZzLk3GVHSwMF4=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: c329a428-55df-406e-c63e-08ddef0415d5 X-MS-Exchange-CrossTenant-AuthSource: BL1PR12MB5753.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Sep 2025 18:18:18.4511 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: Paa+zedHWXNKEHazkhnF89E9VgThDU9TgZMt0NqQ70So5MOJot3oXQjCDG7lMbSI X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN7PR12MB7276 On Mon, Sep 08, 2025 at 08:12:59PM +0200, Pratyush Yadav wrote: > > +#define KHO_VMALLOC_FLAGS_MASK (VM_ALLOC | VM_ALLOW_HUGE_VMAP) > > I don't think it is a good idea to re-use VM flags. This can make adding > more flags later down the line ugly. I think it would be better to > define KHO_VMALLOC_FL* instead. +1 This kind of stuff should be avoided, it becomes a very sneaky ABI. Jason