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 41039C07E97 for ; Tue, 28 Nov 2023 02:10:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8DBD46B02EB; Mon, 27 Nov 2023 21:10:10 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 88BBA6B02ED; Mon, 27 Nov 2023 21:10:10 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 705506B02EE; Mon, 27 Nov 2023 21:10:10 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 5D31B6B02EB for ; Mon, 27 Nov 2023 21:10:10 -0500 (EST) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 1A579A015D for ; Tue, 28 Nov 2023 02:10:10 +0000 (UTC) X-FDA: 81505732980.26.4C301E7 Received: from NAM10-DM6-obe.outbound.protection.outlook.com (mail-dm6nam10on2051.outbound.protection.outlook.com [40.107.93.51]) by imf23.hostedemail.com (Postfix) with ESMTP id DF7A91400EA for ; Tue, 28 Nov 2023 02:10:05 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=jIjqguRI; arc=pass ("microsoft.com:s=arcselector9901:i=1"); dmarc=pass (policy=reject) header.from=nvidia.com; spf=pass (imf23.hostedemail.com: domain of jhubbard@nvidia.com designates 40.107.93.51 as permitted sender) smtp.mailfrom=jhubbard@nvidia.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1701137406; a=rsa-sha256; cv=pass; b=VKiLjsjS5T67/M+GzmWM3QTD54rjRfAcZ6DHTady2mcvs+6OTGdcSpO8NIwXQpHxU8+LwX GLCko5sMGkQMf8thKmYgFiLQ2ukyG3qUjhxV8SrGQkrUs9LxFFzRIgfjeo0b/8xxv/4+4h GRWC1sDm63ACWJfMbcsapbM7S/3DzdE= ARC-Authentication-Results: i=2; imf23.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=jIjqguRI; arc=pass ("microsoft.com:s=arcselector9901:i=1"); dmarc=pass (policy=reject) header.from=nvidia.com; spf=pass (imf23.hostedemail.com: domain of jhubbard@nvidia.com designates 40.107.93.51 as permitted sender) smtp.mailfrom=jhubbard@nvidia.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1701137406; 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=ubmcznw19qene2kxfVuKrRYrUJ8fw5+RBKani9eIaVk=; b=wZ2OkT/MExoBTZVG3A5fga7Mee6LM4OWCuhnU5NZTdwmTG6ttwre5x8FivwQNlq/L1nNiA kS/el1ZOSsWANGIdZEAn3TZx4mKIacYbwoKmTii3ruaKDE5ceMTCZCcATrz0ss39GwnMxg Fw1J3UTEYuCUgks23xZ8KidOEMj3Rls= ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=cIn0jUfeLyCLNncUHWIAY24Ks+U0RLQlSsn/IDwoHF1yYROioAzVOsSBIp0OaxoUT4VPtRhHQkDG7skPCvNQJy8Nei/N8Fe72FLsUuBE7QWCztiI2sxtFFcHrpuqgMjM0SkjE2Spco/BrU3VykvfHlzWwg7t0GL9Hs4dS8D7hEEg2pn2yTwne8cLF+OWzlEIDv1OvVXLtETzOMtsUGdvtAERVkqx2CsvdgrLdzhehi/gtHD+2ALvahGGMiMbOp14Q/5v8qrsxrzNZ26GxVJgpfgYClZJWdqgey/465jt7c1ATSRB1plQKCJiS7aTWrhaRcTLs1rAKp3D1dVkeb/pjg== 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=ubmcznw19qene2kxfVuKrRYrUJ8fw5+RBKani9eIaVk=; b=i3AJI6qKzipifFiAnQhvAnuKU2Br/8xjcWDm6AB6GNDWMWhQHYQkR5sBQ35tsZIiRM9q1ON7Z1TNpAsVY2+UXVd5oXOhYQNvJMtg7VK3UoBA4aYeqkfLUqwcxGTot4qKfUeFoLzeNMw+vWPSQPTSKrzKY1KJpYbiuO1iRIMqRXVMZoYmnEuWckh9F//zEGHI5Me+S35T5E8gidZdTJVyKqS9hCgGp+o6dOf6veAk6VWMVk1++MGVpiHBd0ImRD3lsXwzspL0IR64Lpb6PGFp1R1w+GuLR5/CAEzJZ43FGKnpa/mdNaSz7a95x/TFDF8FsEzXGzI/JQaF3Cwd9WT74g== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 216.228.117.161) smtp.rcpttodomain=arm.com smtp.mailfrom=nvidia.com; dmarc=pass (p=reject sp=reject pct=100) action=none header.from=nvidia.com; dkim=none (message not signed); arc=none (0) 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=ubmcznw19qene2kxfVuKrRYrUJ8fw5+RBKani9eIaVk=; b=jIjqguRIFCUK9i4YGxjAiOilereHRzBLRD6OpnRNsH6ySaVPlK86xHlPawhrmkr3LWOV3Bl9qQfVij1HhGvPLJQARKmOLQQtl0KCMCPmdkVs9k4+1CrBStZW4lWkrDceNInQxqKrQPU+ec853Xn78palYCvvsa4YsWjmUv2FxiOrrHvfRKxSsrWny42bt4BQ+PLL++ir93l/7/R/CJzyNBGy2kfK+LoPNWtOpTB7qdYlU4X6RWBZO8BCCyZmunWwBBsAnzM19xoiCILIQZiuJysyla4IynxzohyrM08ADGmHrUU5WrQx6hFxJLrIIqoWD+o8Ol+ke84stpGXU/jECA== Received: from BL1PR13CA0314.namprd13.prod.outlook.com (2603:10b6:208:2c1::19) by BL1PR12MB5221.namprd12.prod.outlook.com (2603:10b6:208:30b::9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7025.28; Tue, 28 Nov 2023 02:10:03 +0000 Received: from MN1PEPF0000F0E4.namprd04.prod.outlook.com (2603:10b6:208:2c1:cafe::41) by BL1PR13CA0314.outlook.office365.com (2603:10b6:208:2c1::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7046.19 via Frontend Transport; Tue, 28 Nov 2023 02:10:03 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 216.228.117.161) smtp.mailfrom=nvidia.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=nvidia.com; Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates 216.228.117.161 as permitted sender) receiver=protection.outlook.com; client-ip=216.228.117.161; helo=mail.nvidia.com; pr=C Received: from mail.nvidia.com (216.228.117.161) by MN1PEPF0000F0E4.mail.protection.outlook.com (10.167.242.42) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7046.17 via Frontend Transport; Tue, 28 Nov 2023 02:10:02 +0000 Received: from rnnvmail201.nvidia.com (10.129.68.8) by mail.nvidia.com (10.129.200.67) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.41; Mon, 27 Nov 2023 18:09:48 -0800 Received: from [10.110.48.28] (10.126.231.35) by rnnvmail201.nvidia.com (10.129.68.8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.41; Mon, 27 Nov 2023 18:09:48 -0800 Message-ID: Date: Mon, 27 Nov 2023 18:09:47 -0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RESEND PATCH v7 00/10] Small-sized THP for anonymous memory Content-Language: en-US To: Ryan Roberts , Alistair Popple , David Hildenbrand CC: Matthew Wilcox , Andrew Morton , Yin Fengwei , Yu Zhao , Catalin Marinas , "Anshuman Khandual" , Yang Shi , "Huang, Ying" , Zi Yan , Luis Chamberlain , Itaru Kitayama , "Kirill A. Shutemov" , David Rientjes , Vlastimil Babka , Hugh Dickins , Kefeng Wang , , , References: <20231122162950.3854897-1-ryan.roberts@arm.com> <9c8f6d2a-7ed8-45d2-9684-d77489bd99b8@redhat.com> <26c361bc-6d87-4a57-9fae-ef635c9039c7@redhat.com> <87sf4rppuc.fsf@nvdebian.thelocal> <51e6c9f1-e863-464b-b5f3-d7f60a7ebed6@arm.com> From: John Hubbard In-Reply-To: <51e6c9f1-e863-464b-b5f3-d7f60a7ebed6@arm.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.126.231.35] X-ClientProxiedBy: rnnvmail201.nvidia.com (10.129.68.8) To rnnvmail201.nvidia.com (10.129.68.8) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: MN1PEPF0000F0E4:EE_|BL1PR12MB5221:EE_ X-MS-Office365-Filtering-Correlation-Id: 9b26f015-e33c-4c46-1829-08dbefb721e1 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:216.228.117.161;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:mail.nvidia.com;PTR:dc6edge2.nvidia.com;CAT:NONE;SFS:(13230031)(4636009)(346002)(39860400002)(396003)(376002)(136003)(230922051799003)(186009)(1800799012)(82310400011)(451199024)(64100799003)(40470700004)(46966006)(36840700001)(2906002)(7416002)(31686004)(70206006)(70586007)(41300700001)(110136005)(53546011)(8676002)(54906003)(316002)(8936002)(16576012)(4326008)(478600001)(5660300002)(2616005)(336012)(16526019)(426003)(26005)(83380400001)(47076005)(40480700001)(36860700001)(86362001)(40460700003)(31696002)(356005)(7636003)(36756003)(82740400003)(43740500002);DIR:OUT;SFP:1101; X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Nov 2023 02:10:02.7479 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 9b26f015-e33c-4c46-1829-08dbefb721e1 X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.117.161];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: MN1PEPF0000F0E4.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL1PR12MB5221 X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: DF7A91400EA X-Stat-Signature: woms6oyif676idkgmfey98ugh9m4saub X-HE-Tag: 1701137405-284837 X-HE-Meta: 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 ln7CCMPI +DdIqprN2a0ZvdFEfjEwqNN1GzacUKIKf44a78z2ioqWHhsCqQL+VCDHVoyubtdTpbo08/q3Zo+bHzo7s1CX6iCXvQWMtBX/AhCTsUbu+i3h3FIOEGZm5lDAjajCyH1LSwfTigOOGG1Mv8tXD1UmuBL2Qqa9leMpmXb8TogfxuLi7fSpv/E68io7UcK3CbbOHhFk0XRy9ef1z+yG4+C9mAaRfVCyfDwmgM5M0a512k/W7LC6SpTjL1mb0zTjQCWyb3e1F1e8Bsl5cUVCthRjMidI/t+0+cY3gclr5CgmXcTIIwCKjOmMJQtQGYE8xMxcL5aEaxMhF2J0sZBtsF6fgWjupBVoXrgfI5hxyu8Ybxo9UzRdTDgJDLlz//KkWmqtJFngcqbvNuYAnqABcqlHUMR/o92XcKX7CKhVD5YifGw+pqABFPU76aOlw2/RT+zpnE0cGO1OcWvtnaUn50CZwLZru6h7uxqgtPbCq 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: On 11/27/23 02:31, Ryan Roberts wrote: > On 27/11/2023 08:20, Alistair Popple wrote: >> David Hildenbrand writes: >>> On 24.11.23 16:53, Matthew Wilcox wrote: >>>> On Fri, Nov 24, 2023 at 04:25:38PM +0100, David Hildenbrand wrote: >>>>> On 24.11.23 16:13, Matthew Wilcox wrote: >>>>>> On Fri, Nov 24, 2023 at 09:56:37AM +0000, Ryan Roberts wrote: >>>>>>> On 23/11/2023 15:59, Matthew Wilcox wrote: >>>>>>>> On Wed, Nov 22, 2023 at 04:29:40PM +0000, Ryan Roberts wrote: ... >>> Maybe that's the reason why FreeBSD calls them "medium-sized >>> superpages", because "Medium-sized" seems to be more appropriate to >>> express something "in between". >> >> Transparent Medium Pages? I enjoyed this suggestion, because the resulting acronym is TMP. Which *might* occasionally lead to confusion. haha :) > > I don't think this is future proof; If we are going to invent a new term, it > needs to be indpendent of size to include all sizes including PMD-size and > perhaps in future, bigger-than-PMD-size. I think generalizing the meaning of > "huge" in THP to mean "bigger than the base page" is the best way to do this. > Then as David says, over time people will qualify it with a specific size when > appropriate. > >> >>> So far I thought the reason was because they focused on 64k only. >>> >>> Never trust a German guy on naming suggestions. John has so far been >>> my naming expert, so I'm hoping he can help. >> >> Likewise :-) >> I appreciate the call-out, although my latest suggestion seems to have gotten buried in the avalanche of discussions. I'm going to revive it and try again, though. >>> "Sub-pmd-sized THP" is just mouthful. But then, again, this is would >>> just be a temporary name, and in the future THP will just naturally >>> come in multiple sizes (and others here seem to agree on that). > > I actually don't mind "sub-pmd-sized THP" given the few locations its actually > going to live. > >>> >>> >>> But just to repeat: I don't think there is need to come up with new >>> terminology and that there will be mass-confusion. So far I've not >>> heard a compelling argument besides "one memory counter could confuse >>> an admin that explicitly enables that new behavior.". >>> >>> Side note: I'm, happy that we've reached a stage where we're >>> nitpicking on names :) >> > > Agreed. We are bikeshedding here. But if we really can't swallow "small-sized > THP" then perhaps the most efficient way to move this forwards is to review the > documentation (where "small-sized THP" appears twice in order to differentiate > from PMD-sized THP) - its in patch 3. Perhaps it will be easier to come up with > a good description in the context of those prose? Then once we have that, > hopefully a term will fall out that I'll update the commit logs with. > I will see you over in patch 3, then. I've already looked at it and am going to suggest a long and a short name. The long name is for use in comments and documentation, and the short name is for variable fragments: Long name: "pte-mapped THPs" Short names: pte_thp, or pte-thp thanks, -- John Hubbard NVIDIA