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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 553F0C27C40 for ; Thu, 23 Nov 2023 00:24:57 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B48488D0003; Wed, 22 Nov 2023 19:24:56 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id AF7378D0002; Wed, 22 Nov 2023 19:24:56 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 997C58D0003; Wed, 22 Nov 2023 19:24:56 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 897138D0002 for ; Wed, 22 Nov 2023 19:24:56 -0500 (EST) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 5E4BCC0C85 for ; Thu, 23 Nov 2023 00:24:56 +0000 (UTC) X-FDA: 81487323792.23.B9DA1F3 Received: from NAM12-DM6-obe.outbound.protection.outlook.com (mail-dm6nam12olkn2031.outbound.protection.outlook.com [40.92.22.31]) by imf10.hostedemail.com (Postfix) with ESMTP id 78BE2C0012 for ; Thu, 23 Nov 2023 00:24:53 +0000 (UTC) Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=outlook.com header.s=selector1 header.b=WWuhZCoa; spf=pass (imf10.hostedemail.com: domain of mhklinux@outlook.com designates 40.92.22.31 as permitted sender) smtp.mailfrom=mhklinux@outlook.com; dmarc=pass (policy=none) header.from=outlook.com; arc=pass ("microsoft.com:s=arcselector9901:i=1") ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1700699093; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=vFYuMfZuF9noQQfdnQCzi87xAPOBq7FJX5YtBGl5Vyk=; b=Yg9v3D+EqYzEcnRDWOmm/MmLPNWNcLC8y1OmTVxoE6AgLntypj49JLLRdcHrqqQDCVP1Iq bNAwBo2jojdl3IZu0cSfp7Sl0bRHTuyD2EJ3k/I2ceQFYra8rqVVjncTW5SdO3zgkC3J84 Mevjgm1bwP58fVjbx/3RoBrbsJn47NQ= ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1700699093; a=rsa-sha256; cv=pass; b=f+6eOkVmiEP3l7ypQSuERTq3Pc1LPLT3dUarMRKhf+/tqzmDqMT0sWgO05KMX6ikNHxHRP cJhJaBgg7dKAj+o7Ns396UNqVAw65TGT+uNo4J1U7dokb38aS/BawCn9w8g2Ub5m1ht/m1 1Y81mn16vbgmvjhVU9KP1S5mHc/Mq/Y= ARC-Authentication-Results: i=2; imf10.hostedemail.com; dkim=pass header.d=outlook.com header.s=selector1 header.b=WWuhZCoa; spf=pass (imf10.hostedemail.com: domain of mhklinux@outlook.com designates 40.92.22.31 as permitted sender) smtp.mailfrom=mhklinux@outlook.com; dmarc=pass (policy=none) header.from=outlook.com; arc=pass ("microsoft.com:s=arcselector9901:i=1") ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=XuqLcjR3Zuzl/X345MeNCTPyYI1YOBIWSPE9IfkFMf7O3PDEVDg4CHsvQqFsPVnO++qvvpN+iXiKXRL3Ag7L4Y2drx8Q0h9ZCzhl3yqr0UZOTLRDpLEEW1R7RImUI85K5WmJSoL7FunOzNoYaBGFlGVF9U3sQTVoEk/Z17LFYn67wCejG/TdqvropKA5Elv63oJQhQVWpDoPJ4nsS8QMsokxiid1v5R37Agn/OJziZ3kmz00uhOS8wZXh0w8zpYUzA13WS3pu7pZeKPMSzdwsE0aRRdMNQMOY6yjLo2Pq/OPLRJnOinL9NUQ5HZhX2/5HELVugZipx2ZZaFkO3AKUA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; 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=vFYuMfZuF9noQQfdnQCzi87xAPOBq7FJX5YtBGl5Vyk=; b=fmQ56rd38+BH6I2CdxUcAKiD0iFhRKzEYZxu1sYSgahAMtsNivkclKw3zoWvxBg7nn800rzVhl9ue179ml6l9SK8jtIJJE8ejgL/exUvXHzaZitWyJSXakgNyBM5N2mluM2qP/vijznw6ZWgJvRJDUOGn3u6EuZBYyxcJaWzrlx5M8bmqUs/8cFlsrbnclNKYZEotOMgK6v5YUUnaRSVweqndwDmfUS/sF12EgqclynZjT9qmPZtVrliqc5pfumz5lqQbgI7e5/6U5vck8I9gPKyGKkQ7nuWEKbgjxOw3rTjk06wNy9U/tMEvX9E0yheEjadmPTU549rTMQDsA8ltw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=none; dmarc=none; dkim=none; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=outlook.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=vFYuMfZuF9noQQfdnQCzi87xAPOBq7FJX5YtBGl5Vyk=; b=WWuhZCoaJLy9g0gvPWlaFRU+cEiYfBFcXtGKfM6ATPGVVqbPyBd4R0orc5iFmaThrIp+nVMBo5KFflIoqbN3f8USvFAnzGc/mjubftOukPLkKS50Kw2EJMCesXGQtBht/zsDhE3f18dLWWqg6hGUvnm+xtsCONauL7I9zIjFLOhRSt+r8PKNS3UkX3yJnE0/p/SCoCFBY3B1qVMKt6QqCj8IUF3IeJxGEuRrQaODkZhFUy3TdE1GUlz+HnsyEN6l+AXu80e85oB/Lf8EuZ1uZv3Idm6ZtWk1GDwEyknIxaa+zXbaaPsoCZTrPp6hw18EZx7Pqfb3Q9hItVzgRrLo+Q== Received: from SN6PR02MB4157.namprd02.prod.outlook.com (2603:10b6:805:33::23) by SJ0PR02MB7295.namprd02.prod.outlook.com (2603:10b6:a03:292::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7002.28; Thu, 23 Nov 2023 00:24:49 +0000 Received: from SN6PR02MB4157.namprd02.prod.outlook.com ([fe80::54e5:928f:135c:6190]) by SN6PR02MB4157.namprd02.prod.outlook.com ([fe80::54e5:928f:135c:6190%7]) with mapi id 15.20.7025.017; Thu, 23 Nov 2023 00:24:49 +0000 From: Michael Kelley To: Christoph Hellwig CC: "tglx@linutronix.de" , "mingo@redhat.com" , "bp@alien8.de" , "dave.hansen@linux.intel.com" , "x86@kernel.org" , "hpa@zytor.com" , "kirill.shutemov@linux.intel.com" , "kys@microsoft.com" , "haiyangz@microsoft.com" , "wei.liu@kernel.org" , "decui@microsoft.com" , "luto@kernel.org" , "peterz@infradead.org" , "akpm@linux-foundation.org" , "urezki@gmail.com" , "lstoakes@gmail.com" , "thomas.lendacky@amd.com" , "ardb@kernel.org" , "jroedel@suse.de" , "seanjc@google.com" , "rick.p.edgecombe@intel.com" , "sathyanarayanan.kuppuswamy@linux.intel.com" , "linux-kernel@vger.kernel.org" , "linux-coco@lists.linux.dev" , "linux-hyperv@vger.kernel.org" , "linux-mm@kvack.org" Subject: RE: [PATCH v2 3/8] x86/mm: Remove "static" from vmap_pages_range() Thread-Topic: [PATCH v2 3/8] x86/mm: Remove "static" from vmap_pages_range() Thread-Index: AQHaHMCcNHra+kumRUKExlyvEEqwbLCF4AyAgAEpOhA= Date: Thu, 23 Nov 2023 00:24:49 +0000 Message-ID: References: <20231121212016.1154303-1-mhklinux@outlook.com> <20231121212016.1154303-4-mhklinux@outlook.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-tmn: [pEL4nMtFZRRevAUIjVYH09Yi70BnciIL] x-ms-publictraffictype: Email x-ms-traffictypediagnostic: SN6PR02MB4157:EE_|SJ0PR02MB7295:EE_ x-ms-office365-filtering-correlation-id: f2b0e916-2c65-4bd2-9f28-08dbebba9a73 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: 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 x-ms-exchange-antispam-messagedata-chunkcount: 1 x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?qUSW7lm16aQL0yw2K+cKqPTwfQaluAXqmzsoR5ApJBlwjeY20wb6d9OWywE3?= =?us-ascii?Q?2vdlPcix288TueDEzVRSp/t1aZ9OPNbfZQ4wT46uGWuqPIICwRGzTqR8SPxA?= =?us-ascii?Q?eb6Puzs1Ze5lmiSazaPUvOGeUhOt3ydgDl1JQn8NYgEYn2wyRbW2/cRdNuQn?= =?us-ascii?Q?RTK0t9YR5Utgc1GH1Vp24DVQX9E+FQQWlyvlVrE3oPOUX0TvBq+b/yzwvv4j?= =?us-ascii?Q?0Uf01ZV4ZswvpPnhZE9f1DV2rrLSWfFgUKEpSa7utW7uvJK6dOpPhIaJ91Hc?= =?us-ascii?Q?qF5h3PsMCgSMg1M+t4UxveLKVXuz7+UtV85w+52VGJpf+MXFvfwAPmYmN/vU?= =?us-ascii?Q?NDqfiUPloST9CCRRRLN9GwaC2ZUH3LvT5uPEudhFG0fjduoYPuV/gMJdadej?= =?us-ascii?Q?RahFMXU3FRI7Ofc2cGyO/+WZ7SUwQdP/UTR5DL2UFoU0u5ighEPS3EEe9WtI?= =?us-ascii?Q?N7BVSwDQ2EDRo1kx9W9JZos0SYBr6s9kxpdsPqQckD6cZToKoXba59LEONE5?= =?us-ascii?Q?hF4pAXW1/dO664vOBgV7TSnORdDRUX5ojJ2gMlcpNfJ5MfWRz5GYUvFREHvX?= =?us-ascii?Q?b8QaLYo2TFOUreNCVEqywxJ3bSx8xF6JNWh1xZXBWuAtBMsyLWJw6GzWJ1XH?= =?us-ascii?Q?R4t/NWqDGCDAc+DOKZfHi5RL6oAetM1TuGPdr+quN9vC3pwJBy4kAXteunWX?= =?us-ascii?Q?E+8wA6P9ETHwzVp1FflU2z01CJztwklHKSNe9ggWzD/g3G3GWXl0idxWsvvQ?= =?us-ascii?Q?uFEjVVxHNwZOexMoSTVc5D3WQDrqHe+Yy0mjvsAy6owDXkeVkqpzCPju4ItP?= =?us-ascii?Q?3GDxZsVmImjFO+eSNKYZQIJPdeJ9fHpLYqaQzofKA38pQYO5zZwMSAs8f991?= =?us-ascii?Q?c4ISM+2p5qcbYgh7gOLTGNHr43fhV60dJQiP9BmydyLXD6yfLjJpUa24Pm+x?= =?us-ascii?Q?NpvrVafPeO8qvxAMYJiOM++lj7d7852lZDvjSo0/WgGyahwUL05ClkuiulIQ?= =?us-ascii?Q?orHO5oM0Ksp+zv4IUnRARfclGr16PHUWZ9J0/Z1ts5m6NFlQB3DuBFECi7r1?= =?us-ascii?Q?s7kKqP2t/RKJ/cippCQ+Uu0F5n61KjUX7QVI4WM3blTpee2A0vffbZUeOy1H?= =?us-ascii?Q?t3EQJWHnLdWUpexzXRzEWjTmX2X4fW8HCzMzx/Dnb0HLSLHh61IDz/YzzY9Y?= =?us-ascii?Q?Gia3PL1pxo7W9MIOQh5qsjeBnZHODcgiTf3DtQ=3D=3D?= Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: SN6PR02MB4157.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-RMS-PersistedConsumerOrg: 00000000-0000-0000-0000-000000000000 X-MS-Exchange-CrossTenant-Network-Message-Id: f2b0e916-2c65-4bd2-9f28-08dbebba9a73 X-MS-Exchange-CrossTenant-rms-persistedconsumerorg: 00000000-0000-0000-0000-000000000000 X-MS-Exchange-CrossTenant-originalarrivaltime: 23 Nov 2023 00:24:49.0698 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 84df9e7f-e9f6-40af-b435-aaaaaaaaaaaa X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR02MB7295 X-Rspamd-Queue-Id: 78BE2C0012 X-Rspam-User: X-Stat-Signature: ch6n7bpdjmdefh95p3gmnppp69f5fudp X-Rspamd-Server: rspam03 X-HE-Tag: 1700699093-962341 X-HE-Meta: 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 HW2WXsYq 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Christoph Hellwig Sent: Tuesday, November 21, 202= 3 10:26 PM >=20 > On Tue, Nov 21, 2023 at 01:20:11PM -0800, mhkelley58@gmail.com wrote: > > From: Michael Kelley > > > > The mm subsystem currently provides no mechanism to map memory pages > > to a specified virtual address range. A virtual address range can be > > allocated using get_vm_area(), but the only function available for > > mapping memory pages to a caller-specified address in that range is > > ioremap_page_range(), which is inappropriate for system memory. > > > > Fix this by allowing vmap_pages_range() to be used by callers outside > > of vmalloc.c. >=20 > I really do not want to expose vmap_pages_range. Please try to come up > with a good way to encapsulate your map at a certain address primitive > and implement it in vmalloc.c. To clarify, is your concern narrowly about vmap_pages_range() specifically? Or is your concern more generally about having two separate steps as applied to system memory: 1) allocate the virtual address space and 2) do the mapping? The two separate steps are already available for MMIO space. Doing the equivalent for system memory should be straightforward. Conversely, combining the two steps into a single new vmap() variant would be a little messy, but can probably be made to work. This combined approach will be less efficient since my use case does a single allocation of virtual address space and repeatedly maps/unmaps the same page in that space. I would need to take some measurements to see if the inefficiency actually matters. Michael