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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> 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-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231127_181015_796619_77974B47 X-CRM114-Status: GOOD ( 20.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel