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=-8.9 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,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 76F8DC433EF for ; Wed, 15 Sep 2021 13:50:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4ECB561250 for ; Wed, 15 Sep 2021 13:50:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234468AbhIONvW (ORCPT ); Wed, 15 Sep 2021 09:51:22 -0400 Received: from de-smtp-delivery-102.mimecast.com ([194.104.111.102]:54864 "EHLO de-smtp-delivery-102.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234212AbhIONvV (ORCPT ); Wed, 15 Sep 2021 09:51:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=mimecast20200619; t=1631713801; h=from:from: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; bh=xRs3iwL2GN66k/6W48nYP2N7/4zO4rIJIIkNfYSSLuQ=; b=NW1bdbCVYhSjCIBgindKLrw8TGhsMXaLqJ0QkhLrug2lzli7KxSail3HXiYj42aoqFdmFo NXzeqtK7C8OmMZ+2APT0krvz8Sn2f4rFBlvwLGDzkKmO8XutDzXXrTFxN9HrCYha+oWw4m DPftBR+RF3LeH56BHGejaO3XqD0VWZs= Received: from EUR05-DB8-obe.outbound.protection.outlook.com (mail-db8eur05lp2110.outbound.protection.outlook.com [104.47.17.110]) (Using TLS) by relay.mimecast.com with ESMTP id de-mta-10-WzxKjQ_FOyCp9ovxI31h5A-1; Wed, 15 Sep 2021 15:50:00 +0200 X-MC-Unique: WzxKjQ_FOyCp9ovxI31h5A-1 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Y8lt9p1Y+LIdUdIgr3fuIzarCZseiGSmYopU30G98+zDs5fp8kr+3twLEoIAcdiv+ka28ZTfxgcTHkGTMxrBqvYpYjx1MHs7jK3ZmZTos43BXkCSuPeRbHKh2hFmmSMFzZ4dcpkaQOJXH9jVzXT16OgriX01UKvToVcVfM15meWUvUDtVZwkNk+BV9q16Wx/BBKPGB8IuP6/phvRsLiyBAV+aXIoQhLnsDoKv/eFi76IuvpcBkb3T8nQsKZo3iDnpNgnHNpd7ZFkzLu5jAa/Mr5G8uzzgik7XKPtZTlxbfRAAq0ZAMUGs5fVSp/ccjgPN3tHo75an6DuYDu7IzkdhQ== 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; bh=xRs3iwL2GN66k/6W48nYP2N7/4zO4rIJIIkNfYSSLuQ=; b=hKb/3wEDzOgnV/lOG4ccZJk/VLhvDji9RO9J29oqaWtt7jrqqabQAy5xJwnxbFUpMIB/PpH8XcBDUc8c0sWqtAv4kWqbV3Fj8MIZn394lkPvohXzl9vJRq28Eukaa5/6KfH9EvPYWd1Ag2Vmu5LjYncxfwKiBmucvWmmPXry1a/fjVlvkt48AdY9yPMHJRmr3F4mYTroB/plskIYjsgYQzathTtAFRkL+pxT5MW5iCcgTbbTqpnHevAvkdMVf1y5N5uNZavsLIyv+xvY3h2y91LXfTi4D42g0TG9jVoVtPYM16l5Sn4cf7VA3GMQJeTVhR4cgVbX1U2pl33FT+WBfg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=suse.com; dmarc=pass action=none header.from=suse.com; dkim=pass header.d=suse.com; arc=none Authentication-Results: lists.linux-foundation.org; dkim=none (message not signed) header.d=none;lists.linux-foundation.org; dmarc=none action=none header.from=suse.com; Received: from VI1PR04MB5600.eurprd04.prod.outlook.com (2603:10a6:803:e7::16) by VI1PR04MB5471.eurprd04.prod.outlook.com (2603:10a6:803:d0::33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4500.17; Wed, 15 Sep 2021 13:49:56 +0000 Received: from VI1PR04MB5600.eurprd04.prod.outlook.com ([fe80::4d37:ec64:4e90:b16b]) by VI1PR04MB5600.eurprd04.prod.outlook.com ([fe80::4d37:ec64:4e90:b16b%7]) with mapi id 15.20.4523.014; Wed, 15 Sep 2021 13:49:56 +0000 Subject: Re: [PATCH] swiotlb: set IO TLB segment size via cmdline To: Roman Skakun Cc: Andrii Anisov , Roman Skakun , Jonathan Corbet , Thomas Bogendoerfer , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Konrad Rzeszutek Wilk , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , Christoph Hellwig , Marek Szyprowski , Robin Murphy , "Paul E. McKenney" , Randy Dunlap , Andrew Morton , Thomas Gleixner , "Maciej W. Rozycki" , Muchun Song , Viresh Kumar , Peter Zijlstra , Lu Baolu , Mike Rapoport , Will Deacon , xen-devel@lists.xenproject.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-doc@vger.kernel.org, Linux Kernel Mailing List , iommu References: <20210914151016.3174924-1-Roman_Skakun@epam.com> <7c04db79-7de1-93ff-0908-9bad60a287b9@suse.com> From: Jan Beulich Message-ID: <84ef7ff7-2c9c-113a-4a2c-cef54a6ded51@suse.com> Date: Wed, 15 Sep 2021 15:49:52 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-ClientProxiedBy: AM0PR04CA0117.eurprd04.prod.outlook.com (2603:10a6:208:55::22) To VI1PR04MB5600.eurprd04.prod.outlook.com (2603:10a6:803:e7::16) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [10.156.60.236] (37.24.206.209) by AM0PR04CA0117.eurprd04.prod.outlook.com (2603:10a6:208:55::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4523.14 via Frontend Transport; Wed, 15 Sep 2021 13:49:54 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: b0b5e282-5bbe-4cf8-0b58-08d9784fb384 X-MS-TrafficTypeDiagnostic: VI1PR04MB5471: X-LD-Processed: f7a17af6-1c5c-4a36-aa8b-f5be247aa4ba,ExtFwd X-MS-Exchange-Transport-Forked: True X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:10000; X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: JaXuFuBrcOfmQDdigdiyDseTXDqzxqZ7D+OcJ7e/NQ+4HjxSamTqC9C19d5ApqvcR/PDEdRLfdfhifzsV9l671gOEtQtTIEsAhDvnq/viB4PG6hhzTfB+Q9Ej1LW49ei01J9zaYHRpwtXByUqn5Pm3rgGgtNhMfAayaC2kHZeVbDz47zabRgCnp8KraclUERRxsfJ0RNkm/XfMij1ZmFTCMQeVAkGPokjTs0lVWfdcMVtfFTWDQg9Rj+fJRIeH81EhqfoxKN2euQJn7HgrCV4ZPWKWpRJuONkU2InfXd+PyiHJKEawjtzx7qOulUeqBaUkAosyES+N39BTZdJkySWJmHZD8r5rSMLbN9O1ouql+ZyfyAihRWE61PACdHUGXRbkmZMqzFyNx0QXHDiI1WrYm4bJ+Ex041VsHkg+ovDguBIlXLIBSfD29CIOCHnkZGPte7jq7n1tnxKTqSrJMcA5JGb3QpemVpHb+mLj+9vUbzFeZNZ/AnAXeqxh3j+arIy7QB6lOZIDkDgivSgoCJvPXHSgPSXWvSqmE6f5SQ66rx76a4pxTVxN+DPTcKCIkwSoU2tq1pQ2YsVABmQBBWk21/V2fr6Fv1IXcX1KE9ETjYPsFojGghKHVhuetvgUcO9pUMqX08hKTWYTrUle9V8/ZwV8i3Gac2fydBxqrZBYObxvXrfHiILcTc16+io0RhRZH5toDLEnwN5JT4di8ewmoKm5ALp+hhKR+33br6ZUrEn5chGDsUp8SUfEZ4Z+Rbj8qd1d8O3OvjapKWSyHry/1LrLPPQQ4sporNAztzyG3E5K2cCt5M1jL3qvKfIsz3 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:VI1PR04MB5600.eurprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(346002)(136003)(366004)(39860400002)(396003)(376002)(2616005)(53546011)(8936002)(38100700002)(956004)(31696002)(2906002)(5660300002)(7416002)(7406005)(16576012)(6916009)(6486002)(4326008)(31686004)(316002)(66476007)(966005)(66556008)(54906003)(478600001)(36756003)(26005)(66946007)(86362001)(8676002)(186003)(83380400001)(45980500001)(43740500002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?TFRidnlrZWxiOFdDZ2lIcFMwTUR2cDVUSGVSbVJUdDlsYTN2elZ1UzRGaGFq?= =?utf-8?B?RFJYcGQ5NDFkMFcrSkdUd0J4K0IrVFVOZGZBVTlGYURMZitVbVoxOVR6Z3Vr?= =?utf-8?B?RlhNM0xZUWVESGt1WDRIK3QvSUl1Y2xKUEtuemo5bW1oZC9YQTNFVTF1bmpv?= =?utf-8?B?cDRGakh5clFrY05TYW5GV2ZNT3dXOGdrWjIyRXphQXY2bmtkZ3NzVitOT2ZC?= =?utf-8?B?ZDVtb05VQ2kwYjJJQ0VHcjk3dmY2Ymc4Z1dSVzk2K0lheDdPaGxubklneXRD?= =?utf-8?B?TUxXMkxEY3h2TmV6c2ZFS3RJNDhlb3hybWlhcmlkM25EaUdLQ1E3WmRMNmlE?= =?utf-8?B?ckFUSDdPdmtwRXkwZzJrazlQcnN5U0plWFRqMTh1NFMrS2h5MnZ6a0ZsOEw3?= =?utf-8?B?dHNuaml0dUxiaDA3M0JyNWQxTnhtWktNckhiekNuYTRkOHFMbGhLZTl1TzdJ?= =?utf-8?B?MzRNcko1WVpwWGhwRXVLbEZ0K2toL3dlLzcyTkZZbFMrNUZaSzJSMDRRU0Fj?= =?utf-8?B?R1ptWlJYZFZzY0JWbGZKUitQK2M4bUxlWDYxSk1pUkM2UitrQStlMUw0NUs5?= =?utf-8?B?dDBkNjViazlsbWIzOHAwMWhEVlp2OUE5TDlrU0lwdk9TblRZbDNqeFl0Zm43?= =?utf-8?B?TnVJSDh4ZWl1azVlTmswU1gyS0dUQkdQdFBZbjJ3bUZqMTF6bnh3SHU3QzNn?= =?utf-8?B?SnQrRC9aYjhvL0pKeEZnRVAzSlBsZGNvMXdoQjNVQW5KRDY5aWQrTllHOWhQ?= =?utf-8?B?Y2w2d216aTBsNnlqSFRXUFF2WWlEQXdJUmtBYmI3NnNnejhMT01RS2JXQ052?= =?utf-8?B?d1lZWGoxeXRxQVVOV3hqazd1MW5LZ2x4dExIQ2hDVW93RVZaeTJudDFBcFg4?= =?utf-8?B?UmNrMXZKaE9BaHgrZ3NPWEhjeVV2dFNkQmVUYUdsOC9BUUcxd2U2TVhORzJx?= =?utf-8?B?RE1tdWFmSkp5ZVJGejdBVXpMZlFiM2VnclN5MUY5SXd1a3E4eGRicWZ2dVRa?= =?utf-8?B?cmxtQUt4UVpOWlBRL25zSVdjWW5QUFR4cTgrNVkrS2pqK3dsN1QrODFyYi9t?= =?utf-8?B?NGZHd25KMjhkR0FscVlaaWNFMU5XaFhCSzlwbk5tV0pVVkFGRnpZK3VHTHIr?= =?utf-8?B?Tk54RjhyNHM4dkNDdEE4OWg3bUptNGozYlJXTVNoVWNLSnVKUWFCWXNQQzNr?= =?utf-8?B?REwxcXdDa2k4OFNsVHJXcmVkSVl5cmN5Vk9rQnQwYm9lVjg0elFiNFBUZjRl?= =?utf-8?B?Wk1CckNFQ2lNa0FNaUFHMkJFL2FuNjdKelpMVXkyTTA2OVlDamlrZjE4NEVK?= =?utf-8?B?WnE5Yms1ZE15VDhCZDU0cWR3MTBaaElKS2Y4SDV5UmJEMll6bzdKL0VZaG1Z?= =?utf-8?B?akVmWmlVUGhIYURZMmp3aW1Lb1dwRFVQRGV2c2FmT0UzWmN0RmxKcytWRmpl?= =?utf-8?B?NGpEQjVxVHFtT3FqVyt0bTFLTGthOHk2clBKMVRneUpwWm1ib2c2RWtTU3Vv?= =?utf-8?B?Q3FzWm9rd0tlL2s3Wm1oOGYrWFg2alJXWm9RSGFJRlpTSVljb2I0eVF3b1hQ?= =?utf-8?B?anVaSFBWQk5SREdYcUN6bnh2M3FqeVBsRWhNeGJrV3NaMElOeHZ6dlIyc25p?= =?utf-8?B?MjNlLzRaQno4cytSdFl6WmRVemtTNmpHODY3TG9DN3Y3cjhxRjBjbGtZeGtn?= =?utf-8?B?RGwrMUVOeTNHcmM5eUczNnhTZk9nSXR3MzNLekxYVkE0eG5RajdkWTVIcjNG?= =?utf-8?Q?ks2N/7BOJPGoHLXLwSSryflzFMuSIcoDBOJ1ug2?= X-OriginatorOrg: suse.com X-MS-Exchange-CrossTenant-Network-Message-Id: b0b5e282-5bbe-4cf8-0b58-08d9784fb384 X-MS-Exchange-CrossTenant-AuthSource: VI1PR04MB5600.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 15 Sep 2021 13:49:56.1019 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: f7a17af6-1c5c-4a36-aa8b-f5be247aa4ba X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: Xsr9MvRkno86dox0iUTJAb/T9srjz1uVr6ApclDgSHv1xh0ZjtgtBgc5lzh5cLO4IQl05t2yiSrGZuxLrCHJgg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR04MB5471 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On 15.09.2021 15:37, Roman Skakun wrote: >>> From: Roman Skakun >>> >>> It is possible when default IO TLB size is not >>> enough to fit a long buffers as described here [1]. >>> >>> This patch makes a way to set this parameter >>> using cmdline instead of recompiling a kernel. >>> >>> [1] https://www.xilinx.com/support/answers/72694.html >> >> I'm not convinced the swiotlb use describe there falls under "intended >> use" - mapping a 1280x720 framebuffer in a single chunk? > > I had the same issue while mapping DMA chuck ~4MB for gem fb when > using xen vdispl. > I got the next log: > [ 142.030421] rcar-fcp fea2f000.fcp: swiotlb buffer is full (sz: > 3686400 bytes), total 32768 (slots), used 32 (slots) > > It happened when I tried to map bounce buffer, which has a large size. > The default size if 128(IO_TLB_SEGSIZE) * 2048(IO_TLB_SHIFT) = 262144 > bytes, but we requested 3686400 bytes. > When I change IO_TLB_SEGSIZE to 2048. (2048(IO_TLB_SEGSIZE) * > 2048(IO_TLB_SHIFT) = 4194304bytes). > It makes possible to retrieve a bounce buffer for requested size. > After changing this value, the problem is gone. But the question remains: Why does the framebuffer need to be mapped in a single giant chunk? >> In order to be sure to catch all uses like this one (including ones >> which make it upstream in parallel to yours), I think you will want >> to rename the original IO_TLB_SEGSIZE to e.g. IO_TLB_DEFAULT_SEGSIZE. > > I don't understand your point. Can you clarify this? There's a concrete present example: I have a patch pending adding another use of IO_TLB_SEGSIZE. This use would need to be replaced like you do here in several places. The need for the additional replacement would be quite obvious (from a build failure) if you renamed the manifest constant. Without renaming, it'll take someone running into an issue on a live system, which I consider far worse. This is because a simple re-basing of one of the patches on top of the other will not point out the need for the extra replacement, nor would a test build (with both patches in place). Jan