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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 84D06EB64D8 for ; Wed, 21 Jun 2023 16:36:54 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E94E710E31C; Wed, 21 Jun 2023 16:36:53 +0000 (UTC) Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3D39210E31D; Wed, 21 Jun 2023 16:36:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1687365412; x=1718901412; h=date:from:to:cc:subject:message-id:references: content-transfer-encoding:in-reply-to:mime-version; bh=gSYF97s6rl7z1Fkt8XEtCfCIMfdU3yUAxhsIVPnV/hw=; b=d5whaTluqL/PUD9o2G8iRo620/Vl6h3ofWrtPRjd44OBsrPnRURI2gQe Ird60LaP2wmRvq94I3YzpTFgf0Jr2Yy1ODO91LU7CN0DqX9U/0tnFNwX7 C4/mhxdJF9jEhjrmfLgXIkb/4vNwLcsbXUBXdCpN7XujW/KAGWfw7nt4z 8GSAX5Ha3djRKCCwfC+ZzFreP1jIBO14slRN9aiLoileRR8AtqV8zjm18 I3XZrwCuZQF+Veu0ViIugXSru4NVqCnzVM5jECGt0nk+WIK9pCfgUkXfS z0QXqpyOCC4O8r51b+I62CXDx2K/Y2xSoqY690vd2Vg6EoO5X3RTVby/1 Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10748"; a="357730775" X-IronPort-AV: E=Sophos;i="6.00,261,1681196400"; d="scan'208";a="357730775" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Jun 2023 09:35:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10748"; a="664728909" X-IronPort-AV: E=Sophos;i="6.00,261,1681196400"; d="scan'208";a="664728909" Received: from orsmsx601.amr.corp.intel.com ([10.22.229.14]) by orsmga003.jf.intel.com with ESMTP; 21 Jun 2023 09:35:56 -0700 Received: from orsmsx611.amr.corp.intel.com (10.22.229.24) by ORSMSX601.amr.corp.intel.com (10.22.229.14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Wed, 21 Jun 2023 09:35:55 -0700 Received: from orsmsx603.amr.corp.intel.com (10.22.229.16) by ORSMSX611.amr.corp.intel.com (10.22.229.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Wed, 21 Jun 2023 09:35:55 -0700 Received: from ORSEDG601.ED.cps.intel.com (10.7.248.6) by orsmsx603.amr.corp.intel.com (10.22.229.16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23 via Frontend Transport; Wed, 21 Jun 2023 09:35:55 -0700 Received: from NAM04-BN8-obe.outbound.protection.outlook.com (104.47.74.42) by edgegateway.intel.com (134.134.137.102) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.23; Wed, 21 Jun 2023 09:35:54 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=LPYuFijmbhk1NWNPnXtlN8YVj8yqFbsUdMApFRaAe0WS8HuEX2FP4vW+Y9h7XMUyrC6OH5udmOLKiNCWWPmk0pM8RN8GNkL7RsFUJIhzortXAeuC7OTzLH0bOJu57aPsnqYR3SAhnz6i4jlxs1DlORSzHOjYenekeJk5kHAr/ti54t4s0P+XVUrpkeJjqpaaNf7mpp5182U8B3SwWXZJkmPB6AjruGIetdqvTuU/ZBf7zC1nAlkvh6lS1nCKfFO9MTiAXl5Gp2qv2GcDX1MZLaSKHWZXu8auPFmGbZlA4LcnuWnxExMNyg1QBv9dFJ37Lh0vibeYY32S//Xfm4bZ6A== 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=qgeXEcmlceq/LkrM1+racpCbjK7hlv6542Q5aHzuji0=; b=X04hJpp+IMKwAgHQV8jLN9n7hTAwIRKR7T/xuokhMQwcqPuLi8XUwxw7li0aE04PQhLzeq8+jcdqNGr8EB5Ikjcur6m/3kJnk0MVVWru8wgJ07Z27AouyAKp4VbZX8j2NM20K79lypOjSXyJOutdLQjBcv2Ur1iMaVyLKqvHZksCcpgp9Fc9IxxWzmOTh5paXJo1E9s1nNsX2A0lzsk1SStBtW97vZORTo1pYQcG851Q4aTVlpYiaSYyAQnkNfQ9pFRgbvYl59kJcmYFb7Z3AZLBWPquCGjQSB0W2eSV/NPi95Kp++ZQsGiL7Md5EkYYBAV1O17UmMdyd2l+Gy1l6Q== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=intel.com; Received: from SA1PR11MB6733.namprd11.prod.outlook.com (2603:10b6:806:25c::17) by PH0PR11MB7493.namprd11.prod.outlook.com (2603:10b6:510:284::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6500.37; Wed, 21 Jun 2023 16:35:53 +0000 Received: from SA1PR11MB6733.namprd11.prod.outlook.com ([fe80::7237:cab8:f7f:52a5]) by SA1PR11MB6733.namprd11.prod.outlook.com ([fe80::7237:cab8:f7f:52a5%7]) with mapi id 15.20.6500.036; Wed, 21 Jun 2023 16:35:52 +0000 Date: Wed, 21 Jun 2023 09:35:43 -0700 From: Ira Weiny To: Thomas =?iso-8859-1?Q?Hellstr=F6m_=28Intel=29?= , Sumitra Sharma , Ira Weiny Message-ID: <649326df1b895_1c0dd29486@iweiny-mobl.notmuch> References: <20230620180759.GA419158@sumitra.com> <79e1f37f-3ffa-0195-860b-08cc890d810e@shipmail.org> Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <79e1f37f-3ffa-0195-860b-08cc890d810e@shipmail.org> X-ClientProxiedBy: BYAPR03CA0001.namprd03.prod.outlook.com (2603:10b6:a02:a8::14) To SA1PR11MB6733.namprd11.prod.outlook.com (2603:10b6:806:25c::17) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SA1PR11MB6733:EE_|PH0PR11MB7493:EE_ X-MS-Office365-Filtering-Correlation-Id: b38ac795-bcde-42e6-460a-08db72759402 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:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:SA1PR11MB6733.namprd11.prod.outlook.com; PTR:; CAT:NONE; SFS:(13230028)(136003)(39860400002)(396003)(376002)(346002)(366004)(451199021)(6512007)(7416002)(44832011)(5660300002)(41300700001)(8936002)(66476007)(8676002)(82960400001)(66556008)(38100700002)(4326008)(66946007)(86362001)(316002)(6506007)(6486002)(2906002)(9686003)(26005)(186003)(54906003)(478600001)(110136005)(83380400001)(6666004)(60764002); DIR:OUT; SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?iso-8859-1?Q?4wLJSdcD0qdd10tl4d4V2nwgyB0gjN7Yn8E/Nrs+PeW+cQfhQzOFh0KpOr?= =?iso-8859-1?Q?0iGBI5XMJ6M+n09TOLnligAfiTNB0fLMSRmO1dH7N73YQs59KFFlyKha6l?= =?iso-8859-1?Q?uX33g48IzI1k5iYsrbjmVXMgpx9D9Yp1ATCc76GbYbyXOQFuu2r1YPydpK?= =?iso-8859-1?Q?o3MTnD7Gb572ucs8hhZAXKiTT0JeU52TwlGG2WLR9HZ3Urd8QN7QGetCy4?= =?iso-8859-1?Q?I06fJYsN9fdu3uKtMHiusTP7h89hVNV28pPma7JHxqHPX3Cd1zV3Ok0dBp?= =?iso-8859-1?Q?tCDDsZS8pE42D/cZtypJmqKXhdLl2SN5JK07oubqv0Qt65zEAUSyZsyUfn?= =?iso-8859-1?Q?hgp7y/6UTnQOZhezOvOi88fWhrFPAfphYmkkRI3ZGqLed/QTpbmNRc/Pmy?= =?iso-8859-1?Q?8X10yJbMIFo/3zHwQtVcyqUfn2QmhpID8vjHOD9MjshfAvbrBSyOfbAhZw?= =?iso-8859-1?Q?BcBGPB9YYoakog5BoakZe98+KLEIVe03UYspVRvKOerXtYYCnd6xwqqLZ3?= =?iso-8859-1?Q?5/x5cJfIPpt7tO/bWw6nj5+aLUGilUCoPO23G3SuzmMNlwxXAWQJhOZG79?= =?iso-8859-1?Q?DkGZwwweejfyJEnEEQQYTrDonDp1XN/kNVQBJ3ltwREiLtnpkuirDgXzPI?= =?iso-8859-1?Q?99/VhL3aG5xumYnxCRFx+yXNl+sRLbxLMCXTh8gP5YGKUwvC/ATwQ0deuW?= =?iso-8859-1?Q?KF66xopt///QY+SbxR4fO8A7yzwC2wBOJ5YcEKHFAsLXq+K6g/yDgw66oN?= =?iso-8859-1?Q?K+DYxuIgsnvbrA8Ixp2QZ9N56x1cJx7s9zi2rFwWlS/gzAaViA1g86Phpg?= =?iso-8859-1?Q?oHyk4T5t5vpjWu/3sEaXoscTfsgGwcMshNu6vNyHE9IKC5AoWfgsJsplhV?= =?iso-8859-1?Q?rIdhbr/CE/n1s9XVxv/sbB63VEI4MLAG0YDFppyBojfC1xjr9ayDYh7qfz?= =?iso-8859-1?Q?+P2hmkahkWKkjvLTIzTvDqJDTq4ZBacOGBB6S3X7xm7BKWsCAim5SYKCgl?= =?iso-8859-1?Q?+IFfnz/4BWhh8uNMXXdR8PdRZrNZ4I/lUblGl4HBd2p/+IlN3Q+FEfqyAW?= =?iso-8859-1?Q?2aJ4I1U9FUqAuIDXIXjSI6prGJTzQCGiUNQ/6HSWDvLRKYL9Em6GeEXhnq?= =?iso-8859-1?Q?lpgeW+0gZTRo2t8XDwS9jwfR/RWSNxYfcybfz2kr1j8JR3LaqrSDcPW/ye?= =?iso-8859-1?Q?PEDpgyhKheI3G+YzWJ6anXu9px5f86kbb+Eem7Zq04nz+0Hzmt/czyVOER?= =?iso-8859-1?Q?P6bH2iRApVorEloKdZo0G2VWVlIuYbc8XBDWtGnTUloIKKsH4hir7StdLf?= =?iso-8859-1?Q?Hb7yMJRuITxIQP7MZnppjlraewMSI9f//s1pQ+n9M7IsiUZUFr34m/cycR?= =?iso-8859-1?Q?TOqApGzU0xjHZ0pNsJcAvOz4DqygE4M+Xqf28ucHK/ZdHkvk0amL4QPXU4?= =?iso-8859-1?Q?93qG+1R3Xpzc+632NSihyrC7EDeyy2gDIg/5W6YJmwygSNWDzmtVMLQsEV?= =?iso-8859-1?Q?WVFSGLgB00yHpqzvFAUouYQXZs53NodCiiZ8T5UsXG+mu4DYPrZZr7GJ7O?= =?iso-8859-1?Q?zwuoS1xR0BKZMvn0IxfkmE5E0p7C0VP0sZPg4WnGKVL1D0Fo8GGgnWgB/x?= =?iso-8859-1?Q?qoZt9VlP4FXOj6TPhEPJGjeAyL8PSJEmxN?= X-MS-Exchange-CrossTenant-Network-Message-Id: b38ac795-bcde-42e6-460a-08db72759402 X-MS-Exchange-CrossTenant-AuthSource: SA1PR11MB6733.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Jun 2023 16:35:52.6687 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 55cTgIPdqj6RyrwGXRhjiR27xTP0lkaGruHrmGXcvks3uLu9T3OmEuUDc2eH2VGBB8Evwc4PA9WM2hv2PUvitA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH0PR11MB7493 X-OriginatorOrg: intel.com Subject: Re: [Intel-gfx] [PATCH v2] drm/i915: Replace kmap() with kmap_local_page() X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Deepak R Varma , Fabio , intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Daniel Vetter , Rodrigo Vivi , David Airlie Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Thomas Hellström (Intel) wrote: > > I think one thing worth mentioning in the context of this patch is that > IIRC kmap_local_page() will block offlining of the mapping CPU until > kunmap_local(), so while I haven't seen any guidelines around the usage > of this api for long-held mappings, I figure it's wise to keep the > mapping duration short, or at least avoid sleeping with a > kmap_local_page() map active. > > I figured, while page compression is probably to be considered "slow" > it's probably not slow enough to motivate kmap() instead of > kmap_local_page(), but if anyone feels differently, perhaps it should be > considered. What you say is all true. But remember the mappings are only actually created on a HIGHMEM system. HIGHMEM systems are increasingly rare. Also they must suffer such performance issues because there is just no other way around supporting them. Also Sumitra, and our kmap conversion project in general, is focusing on not using kmap* if at all possible. Thus the reason V1 tried to use page_address(). Could we guarantee the i915 driver is excluded from all HIGHMEM systems? > > With that said, my Reviewed-by: still stands. Thanks! Ira