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 X-Spam-Level: X-Spam-Status: No, score=-7.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MSGID_FROM_MTA_HEADER,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C087EC07E96 for ; Thu, 8 Jul 2021 08:10:38 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4463561CDF for ; Thu, 8 Jul 2021 08:10:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4463561CDF Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=amd.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C5BE26B0011; Thu, 8 Jul 2021 04:10:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BE5156B005D; Thu, 8 Jul 2021 04:10:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9E9106B006C; Thu, 8 Jul 2021 04:10:37 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0047.hostedemail.com [216.40.44.47]) by kanga.kvack.org (Postfix) with ESMTP id 747A56B0011 for ; Thu, 8 Jul 2021 04:10:37 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id C1EF61C961 for ; Thu, 8 Jul 2021 08:10:36 +0000 (UTC) X-FDA: 78338698872.29.89E902D Received: from NAM04-BN8-obe.outbound.protection.outlook.com (mail-bn8nam08on2079.outbound.protection.outlook.com [40.107.100.79]) by imf23.hostedemail.com (Postfix) with ESMTP id BCC1C9001B05 for ; Thu, 8 Jul 2021 08:10:34 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=FYoH/c1tiPA2EKIQIURz3+sNI390A9Df3cQo9VVU13NzPZA1asUDozarUjuZjXhMli7GnjaJInpKNa3875LKpe67v4Dx7dzxbDPg3UNHG4OBMa1xxoBaHJ3HV4mbOB5D4nIQ/5WzOkc7H2lJqgsMfWgFqCKfmvwdzvjB2iBwtXHKYst0qcAvaHl+VKRmW663oie1n0tdwRZiEhB46hhB8UxkCb/yV1n1zb1zAy0PQqIdR/ztPtnpuJiObelfFR21nEJQDbw0jmoP9RDFGNKBE+BG+magAY6jTqutwpWj2sGc0fR2Re5WmnMpA8AesDSKL6xsvlFg9iwaHVxUJhYzcw== 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-SenderADCheck; bh=BMO1kMg1XjTq+X+UYxazKejnuvisMJ8gy0SeMKIAegs=; b=TSsOnKsJyQune7VWB1Z8DBq4haqTscjmboQSachVfkhzo8D+nptDv/sYDDWEC4GhJs7zsmYRs5S2QvR09yaQF+80VLpSMOA+k/F/xjNNZ1BlfLLBXQCwlG+Oh+QzTZO6FQNV3wGPbbAM4Yovs7856UchJFywpI3yYZDWucHM479IPCnjiYuMkChYHHKoHSjddbaEcWIvBY7ABlzmxRgoQ7AZHtv57iaxm2ZhiG6Ru+XsU87oth/SIBFWVVnOUGMllwewB4b+JxomKN9TVf5BOkGRSsUgoVLTcLqEwGhSk9yEs/dd8Xqub6nKs1svbgeLExJNZk5g2cuTvVnme6vb/A== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=BMO1kMg1XjTq+X+UYxazKejnuvisMJ8gy0SeMKIAegs=; b=h8LNI0tMuvMD8blnbSRW3RrfDEOEUnZ2hqlo01MBiXm7wyEV4zyEgWnIRoTPgDzPl95oq3L/JR0tTrFbCixAoo13pWXFA6A0i/xQsrvdNDnkKJ+JDdPOuSj2BbEziUveT85saraE59fa53S8/mHQv2xYWmQ8eNAT3gzyaW3KbKw= Received: from MN2PR12MB3775.namprd12.prod.outlook.com (2603:10b6:208:159::19) by BL0PR12MB4897.namprd12.prod.outlook.com (2603:10b6:208:17e::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4308.20; Thu, 8 Jul 2021 07:37:59 +0000 Received: from MN2PR12MB3775.namprd12.prod.outlook.com ([fe80::6c9e:1e08:7617:f756]) by MN2PR12MB3775.namprd12.prod.outlook.com ([fe80::6c9e:1e08:7617:f756%5]) with mapi id 15.20.4308.022; Thu, 8 Jul 2021 07:37:59 +0000 Subject: Re: page pools, was Re: [PATCH v9 1/5] drm: Add a sharable drm page-pool implementation To: Christoph Hellwig , John Stultz Cc: lkml , Daniel Vetter , Sumit Semwal , Liam Mark , Chris Goldsworthy , Laura Abbott , Brian Starkey , Hridya Valsaraju , Suren Baghdasaryan , Sandeep Patil , Daniel Mentz , ??rjan Eide , Robin Murphy , Ezequiel Garcia , Simon Ser , James Jones , linux-media , dri-devel , Mel Gorman , linux-mm References: <20210630013421.735092-1-john.stultz@linaro.org> <20210630013421.735092-2-john.stultz@linaro.org> From: =?UTF-8?Q?Christian_K=c3=b6nig?= Message-ID: <798f5d1d-b64c-8c73-bfe6-701893820ff0@amd.com> Date: Thu, 8 Jul 2021 09:37:41 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-ClientProxiedBy: FR0P281CA0087.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:1e::12) To MN2PR12MB3775.namprd12.prod.outlook.com (2603:10b6:208:159::19) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [IPv6:2a02:908:1252:fb60:bc19:c1e3:6307:7e3e] (2a02:908:1252:fb60:bc19:c1e3:6307:7e3e) by FR0P281CA0087.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:1e::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4331.10 via Frontend Transport; Thu, 8 Jul 2021 07:37:47 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 48bb7de0-f498-4360-da6c-08d941e34e98 X-MS-TrafficTypeDiagnostic: BL0PR12MB4897: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:8882; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: Q7A1LkSEDESTA/jbLk0xHnbe49n1De6MTk+6NsuptzwNTEAEph263DBVoAMpaIHDhaRf9FOo9aJPRhxZwp7GWT6oAVmcf3/ma0ufWTIBcM+vyjpkuGNYwRedWV1cc/7fMnxPihoFhy2CJdCwrDdjiSXAjui0sSUh8bzfdZA9fFg9F5DcSDa7NkPWNqiZBLwKA1IFGqMVeVvigPYqyc6D97EzrI+xmDoAzDay32HRe7Jxn8xKb5xIXP9rWUq6lStV613G8tPEtWCM1r/dJeVHzdnsTmUDGrynjCKxI3OLpQqo2t0D5GGT6S98BScMQ8fSyfjKiY6sGMF6LWcDSIFTl03o0NZTHKu7Y+qmL3MPbtu0mKZxI55vlM52qaFvSCBz0Yw9XuFsj9U98c6tA+2CwldKU8aVnksqMIzL+HqtZUwr8EzbizfUg9QFp29xh7O7TMPvNsPLn0dZep1jdxZ4/6w83ycdXrxon0+J5BrmOWYgl8QeeUMsfOXTj9dsDluEKrtPweWNnMs105qYXsGadinFABITwYqCDo2rq55EvLvpS/mrYAlyX6Ugrz0BWZ8hJcDbpIHlp8KeQ3J66JMEZeN9rMY8qA9twXma/r3E+PGcqnmZIt65A1MncnmsfWl5Q7j4WQA16/MBy3xTbmmX5HcLsHS2JclVQ4UJXDraxC2oYPMpoUXqFRGR0c9qI0JbFXm8BnhZkGLSYyXr+UXbntHU+mC2YhUMeRcLmyDMcpsCCNcqw/UWhiHqhRbY5j0B X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:MN2PR12MB3775.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(346002)(366004)(39860400002)(396003)(136003)(376002)(8936002)(66556008)(66476007)(38100700002)(31696002)(6666004)(2616005)(8676002)(4326008)(316002)(31686004)(54906003)(478600001)(110136005)(7416002)(6486002)(66946007)(86362001)(36756003)(186003)(2906002)(4744005)(5660300002)(45980500001)(43740500002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?emtvQ05YYW1yMXJJUzZrVlJMVHpTL0x6c1VJS2R0d203UWYxMytwdVh3RFFV?= =?utf-8?B?QjdGbkxsbmF0UVMyMWN1cmg5eDNyRnpKanpmT0VZNFdlemY3MDgwNmlCaW53?= =?utf-8?B?dytOTnFGZmRqWkhEbGx3eGlJZkRINVJSRGsvdTRWUm5STDRFNXRFL3dvMXZT?= =?utf-8?B?bG1FdnhhakZNZ1ovSEFLWnhORjlLZTFvNzIrV3R1NnJianh5VFhkVUxGTXQ4?= =?utf-8?B?cmE3ZG0yWlRVejNUK2R5bUt3SjJ4OFptRml1SG1DU1FoQ281TTFlWjBIMXcx?= =?utf-8?B?QlhZcno2aGdFNUVUcTM4Uyt2QzFodGdnVXVJaGcwcUtwaHFqZkU2MjhTeFJu?= =?utf-8?B?Vk94UXM2Y3laQXd2azdFSzRERm5vdWJzN01ueVc5VnRuOGErbzhWeWNybFg4?= =?utf-8?B?ZkdDNENSelRKcGMwamY3R3lFYXZaREZ3UHRhdG5PQlVQb0o3aDdWOHl1L2p3?= =?utf-8?B?TUVCaExrU3RKVE5BRXR1VTdFZGt3eUlVWjZ6M2k1VXFpQ09tWUYwNmpYeFdC?= =?utf-8?B?T3ROWlhBMU1vUFVsc0c2dFRxVFBaVFo4bFhWVFdIOVRLUnIzRWUrVURWdFlv?= =?utf-8?B?NVB4VU9hbWs4N1gyNCtCWXpXR1RaSFM5ZksySXd2Q2dsbEdpc1kwemxkY2lU?= =?utf-8?B?cU1CSDVoTVlSM2QrT2Z4MVpwZnI0UkYxaFFtS1dUTmh3R2xWUnJ4bWd6UDhQ?= =?utf-8?B?SFo1bDB5c2EreWpRNnloTFN6VFY1NVE3ckhWNzIrRFNvY2RSMkxqaXB3MTI5?= =?utf-8?B?WnhDMTVBZTNFQjFkUFFKRlVOekZkR3dUdm9HRWM4Ny9IWEpIVGt4ODI1OVQ2?= =?utf-8?B?RGl0amhodzdOWTdaNG1vaUpwMlRKeXdoVXNzL1Y5ZnRwUFU1cEZnMWZwWXRs?= =?utf-8?B?cnllNVJsMDNkYU9QekE4S2dsTU93dzZxNTAvNHg0cGcwWWF3ZkNZQWk3Myta?= =?utf-8?B?WHNNc0Uzc0FRNERoYVV4RmYrMFJuOUJaY1FiVUZBa3NIY0JhYXA1UGMzR2U4?= =?utf-8?B?RmdJSElwRURaSnFEdVg0dmlLR2tvNkNYY2VtY3k4VE13ZGRwUkNOZzBpK3dl?= =?utf-8?B?c2ZvRzdDVVk0V2tydHJaSnlRUGNoWjAzd0Y4Unp6MXdUd0FVZHVLTS9xYVh1?= =?utf-8?B?RFRkNGdnSmVWRWQvWjVGaDhTM1BoVGRxa3drTzkrTktNcnh5UmNIY0c4Nm1j?= =?utf-8?B?MmlSV0w1RXNyVVdqd055ZEhORzNDWWhsYnFrM042NjAzU00vcU40N1F4T3o0?= =?utf-8?B?RzExKzRESExsTDBHSlIvWWFJWjBmcStMejJuUXFGdmRLQ0FHdjdQNXJkY0Ix?= =?utf-8?B?bkxZL3J3OHBGejJhQXpQd1cySGNjV3ZRSGg3RDArZlAwOGF4OUhTUXhmdVFJ?= =?utf-8?B?NGQ2OGxNKzBLaUtTR0hsQ1Vlc1VsUi9wdjRRYXlKeGR1VmJicmRJeDFVUW9y?= =?utf-8?B?WStlRXQ0bWwvSmpGOWxtZnJFSlpWZWQzM2VaazVvMmZRSlRleWFHVVpPSlll?= =?utf-8?B?L0NMcXhkUk9WWks4aG54MGY3bHEyUEZ3c3BuOXdPQXlTaG5JTFJFUWFWc3NR?= =?utf-8?B?WEdrU0Zqd0djaFZJSVZyNjhzL0Y3YTlUazJ2SFFHWC9MTE1TdngwMGwxOURQ?= =?utf-8?B?ZzhuZkV4OVpvU2xOekVRSXV5L2dNWDI4a09UaFBWRnZ2VU1JSnlQQmVBMXBy?= =?utf-8?B?dFVxT0xjanBXZGdXT085WDIzTWQ3clV4SjFtL1RWcUZBdEp4TEUxWnpHb2o0?= =?utf-8?B?emdlNnpKS2J2WUhqbXpnbm5OckZWOFJuYVkrN3NkamRBM01MUXFycE8vRlVo?= =?utf-8?B?Tkt4dkdJUzR2RU1vbG4zQmYxb2xqaDdsRVRESzRyaElqMXJCOFlrWk5QZnBr?= =?utf-8?Q?DqpqifLONl2XA?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 48bb7de0-f498-4360-da6c-08d941e34e98 X-MS-Exchange-CrossTenant-AuthSource: MN2PR12MB3775.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Jul 2021 07:37:59.5619 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: +09IUgizJvH0pK6ASmIdu6wXs+FQL+1voQTYzWfsPEwW+MGWVkQYnRqO8DTG9N7a X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL0PR12MB4897 Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=amd.com header.s=selector1 header.b=h8LNI0tM; spf=pass (imf23.hostedemail.com: domain of Christian.Koenig@amd.com designates 40.107.100.79 as permitted sender) smtp.mailfrom=Christian.Koenig@amd.com; dmarc=pass (policy=quarantine) header.from=amd.com X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: BCC1C9001B05 X-Rspam-User: nil X-Stat-Signature: ydendhawxahos8gq1k1q5cdkhjg4qa1r X-HE-Tag: 1625731834-878379 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: Am 08.07.21 um 06:20 schrieb Christoph Hellwig: > On Wed, Jul 07, 2021 at 12:35:23PM -0700, John Stultz wrote: >> So, as Christian mentioned, on the TTM side it's useful, as they are >> trying to avoid TLB flushes when changing caching attributes. >> >> For the dmabuf system heap purposes, the main benefit is moving the >> page zeroing to the free path, rather than the allocation path. This >> on its own doesn't save much, but allows us to defer frees (and thus >> the zeroing) to the background, which can get that work out of the hot >> path. > I really do no think that is worth it to fragment the free pages. And I think functionality like that should be part of the common page allocator. I mean we already have __GFP_ZERO, why not have a background kernel thread which zeros free pages when a CPU core is idle? (I'm pretty sure we already have that somehow). Christian.