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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MSGID_FROM_MTA_HEADER,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham 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 08B6CC433DB for ; Thu, 25 Feb 2021 21:43:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7932464F2C for ; Thu, 25 Feb 2021 21:43:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7932464F2C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CE6B96B0005; Thu, 25 Feb 2021 16:43:39 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C70466B0006; Thu, 25 Feb 2021 16:43:39 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B0F598D0001; Thu, 25 Feb 2021 16:43:39 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0105.hostedemail.com [216.40.44.105]) by kanga.kvack.org (Postfix) with ESMTP id 94E586B0005 for ; Thu, 25 Feb 2021 16:43:39 -0500 (EST) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 6580C18020C2B for ; Thu, 25 Feb 2021 21:43:39 +0000 (UTC) X-FDA: 77858117358.08.4479706 Received: from userp2120.oracle.com (userp2120.oracle.com [156.151.31.85]) by imf20.hostedemail.com (Postfix) with ESMTP id A023AE7 for ; Thu, 25 Feb 2021 21:43:38 +0000 (UTC) Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 11PLTacB022585; Thu, 25 Feb 2021 21:43:34 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : cc : references : from : message-id : date : in-reply-to : content-type : content-transfer-encoding : mime-version; s=corp-2020-01-29; bh=KhfZtiJsUCq9NleuxQLQAP4MCIdxj1iF+lpOWj0oVDk=; b=I8pvLvXSbjZJaENSs5nT5o6eG2tq9kucwmAjalm4WtOsNxvOmVu7X48m/VOfIVRm1Ypi aEHYNeJP8pGn34yr6w9zdKRqkZd/71q5DbYsiZrdd8OAq8wXL8r1iJhb8pHetSwAuNPd ZUJWHx6P3OouP2/Y/b0PwY6KldGs6UPCXg74v1MrpWGz1W7hwdUn3BWb7k/3hpXY2OoG b8jFkwImymEl0oUIHNUdmezepwEARs9vQkcnIBuiIWlTIITreYo8bK9xu2vJKpqeZRpS HhMKqMUItrh/IABGoW7zM+a9cMZ/mFUIFza1dfilIDgsGM1lUN47vaOcyXK1tUSND/S/ Dg== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2120.oracle.com with ESMTP id 36ugq3pwu4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 25 Feb 2021 21:43:34 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 11PLUiVk109928; Thu, 25 Feb 2021 21:43:33 GMT Received: from nam10-bn7-obe.outbound.protection.outlook.com (mail-bn7nam10lp2109.outbound.protection.outlook.com [104.47.70.109]) by aserp3020.oracle.com with ESMTP id 36ucb2kstg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 25 Feb 2021 21:43:33 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=OBkIGdNkMPkZxsVXrKa6t85LiADmlb4DTHUhJKgNPk6dPi9s0EX5NDsJkiT9JhTfP7318UnkfMTe7TT2sFMClJkzTgIXXV65iX/Z3AEA5+ofRnfdNOgcY2NnrcWoP/+PTL+qK3XSdacBEofy82kbSSQgOpGYG25xbcsO7WW8WizDtxN12b9QYQ2CeLgvI5Iomge7Xs9Tpy7kZfnCHUXi5ZPwGLAzZWHMJhz2klxTBOq49oKYYoG3HiFXhZ0CHQtfRTdPLt4XdlJzaAgxogILZy5JzxVwpMD4tbFhce0PQP4BfpdF+ksaC0Xen5QonowobkQvithsex1TqFkhBvk4lA== 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=KhfZtiJsUCq9NleuxQLQAP4MCIdxj1iF+lpOWj0oVDk=; b=NT29Wrr//elOsC0tl0O+Mqr/OCsYjRAKbwCz4xtyIGTb2TTzgd4pd7qZNxg8Gwpm93AkGYU/Wi54c//VMXxG6crJsRgLcmsIj9lPCYeKnt1FKIay2NejgWbgNFXLeLjTB5/3w7g3YpBEeHD5IKHj7S017sunnDx2EkECVPyePFuLxNQFu2kPnV9TXKiqRWwXCMrq9p3ojM8bdbC9r+NtpGoq9Fk/+JdOkspc/LGzNKhy1YAGDPw+UfVh+orZI+7cgf1gRwnbOUhvkdauC076T7M0/TuEApMPISFw7RVlZZNZwVj4qLekDt6buXYBaDw8/6uOKkaWgbn9jIJ6QNU5vQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=KhfZtiJsUCq9NleuxQLQAP4MCIdxj1iF+lpOWj0oVDk=; b=al8uZagU5MJQzwOqz6JLeUP8LmRqNqrgbdzq+mUDBMYaxzAzZ1t+9Labce1Fn4iEabdQBTVKxiAJaPUW70fMuesYP21N4MCdn7NGnJdSf/L59Ok4m5lhzgt43z63n2y2qFD7D+kzyEK4+84ha2V/wvpdVa0cna2UVU2mnF6hKl4= Authentication-Results: vger.kernel.org; dkim=none (message not signed) header.d=none;vger.kernel.org; dmarc=none action=none header.from=oracle.com; Received: from BY5PR10MB4196.namprd10.prod.outlook.com (2603:10b6:a03:20d::23) by BYAPR10MB2823.namprd10.prod.outlook.com (2603:10b6:a03:87::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3868.31; Thu, 25 Feb 2021 21:43:30 +0000 Received: from BY5PR10MB4196.namprd10.prod.outlook.com ([fe80::980e:61ba:57d2:47ee]) by BY5PR10MB4196.namprd10.prod.outlook.com ([fe80::980e:61ba:57d2:47ee%6]) with mapi id 15.20.3890.019; Thu, 25 Feb 2021 21:43:30 +0000 Subject: Re: [RFC PATCH 2/2] mm,page_alloc: Make alloc_contig_range handle free hugetlb pages To: David Hildenbrand , Oscar Salvador Cc: Muchun Song , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20210208103812.32056-1-osalvador@suse.de> <20210208103812.32056-3-osalvador@suse.de> <9ed946df-9c6c-9a4d-4be9-2f32809974f7@redhat.com> From: Mike Kravetz Message-ID: Date: Thu, 25 Feb 2021 13:43:27 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 In-Reply-To: <9ed946df-9c6c-9a4d-4be9-2f32809974f7@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [50.38.35.18] X-ClientProxiedBy: MWHPR18CA0031.namprd18.prod.outlook.com (2603:10b6:320:31::17) To BY5PR10MB4196.namprd10.prod.outlook.com (2603:10b6:a03:20d::23) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [192.168.2.112] (50.38.35.18) by MWHPR18CA0031.namprd18.prod.outlook.com (2603:10b6:320:31::17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3890.19 via Frontend Transport; Thu, 25 Feb 2021 21:43:29 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 11ccb53c-e521-4a2a-cf69-08d8d9d6644a X-MS-TrafficTypeDiagnostic: BYAPR10MB2823: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:862; X-MS-Exchange-SenderADCheck: 1 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:BY5PR10MB4196.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(376002)(136003)(346002)(396003)(39860400002)(366004)(186003)(66946007)(53546011)(86362001)(478600001)(4326008)(316002)(16526019)(31686004)(26005)(2906002)(52116002)(66556008)(5660300002)(110136005)(2616005)(956004)(8676002)(31696002)(66476007)(83380400001)(8936002)(36756003)(16576012)(54906003)(6486002)(44832011)(43740500002)(45980500001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData: =?utf-8?B?YXk1S1NLb0JXVU1teFlxRjJWeVNRRE9zMjBNa3d3SWZQVitKK2Evc1J3NHRO?= =?utf-8?B?UTN5VTFxYVdTR1hPVjFpTnNTYWx1eS9QWFA3RFhvUytsSHFNOWprK0RIN1B0?= =?utf-8?B?enhQSVRTVGtVT0RWNXU2dzRnNkN1WGJMZnR4ejljdVdiK2lleEEyWTVDN1hJ?= =?utf-8?B?blp3ZzF5SGF0VHUyVUtJTk5Qb0tsMzl1UEcvS29RSm5mWGtTTUNCczdHb3Y3?= =?utf-8?B?VzZ3K000WFdzNWo1ZE9ESS9VTFZSTmtTWlM5MDhzQVlIZEpkZ083MmJnYmFy?= =?utf-8?B?aGNJajdYbDhmdTBXd3pudkluM2NHUThVU0czQjQ5U000TXhocTJsdm5GdGRq?= =?utf-8?B?azA5L3FLelFMUW0xQkxWWlhwQUc2N3Y5V0UxMkhBS3crdjVjWk5hVS9KRXZB?= =?utf-8?B?ZmdyM0tBbTNEUEVBVVNjNDVNb0lxSWhyb2U0cDlsOXpibjJlT0oyVHNZekZo?= =?utf-8?B?aFdzZUhTK0N4bGVrYndHeE5mWGZCUCtMSU9lN2Q5SGFGdXBQYXFLbWFFYkl1?= =?utf-8?B?S0VIZjM5Yk1wdDNQcU9LREVmTUZpVytqTytZMFRHK1VudU0wbVJscU8yS3NG?= =?utf-8?B?cnpNdVVYdm5oQ2dxVGU4dklkRElGRW9LY3hndndGTlNPN2RGRkpxNitNUk9L?= =?utf-8?B?cEEzU1E0cnptWS84bDZkeGpWbFhvdXJmUERWWDFmODlpUXp4aTdFa1lRV0x5?= =?utf-8?B?aTNUdUZzczBXUGVsMGtqR0s5Z1pCME1pem8yc2NjZXVzNnFIenVrL0RDN254?= =?utf-8?B?VkVNeElud0FIMG5LU1NrSVdRTFl1RXZtaVhRc0VMS3N0N2pDdE5qS29VTm5Z?= =?utf-8?B?UnhUTjQ1Q2lKblNXR1dXelJ6WjRXc2Uzdi82cHp5andic25jR2ZxNWdVcmlv?= =?utf-8?B?STRuR2t6VU5uY0hOb2czUzBVNm1LbEErTmdsbjFsU1pHZ2RzdDlyUkRvak1H?= =?utf-8?B?RGJjdmNmdUd3ckZud3FxUUhmK3hqM21pNy9jVEQrWW90YkFFSDVmdlZkYjBE?= =?utf-8?B?V1BiRWg4YlpCZ1ZPNzM3NXlHa0dYdlhIRWYzTkZ5NzI1eDZ1QXZqWXpNeGo3?= =?utf-8?B?cUdYRjJkeWM4bUliYjFqN0FWVVUvL1ZaLzRHcE0wSEZCcks2MnJVS2dIVkpZ?= =?utf-8?B?cGo4anhFOEdFa1RLWU9jUXdLU3NVWEg1c0ttWVRzdmdXODZvd2YrdGluMkdE?= =?utf-8?B?MWE0L2FYcHNpV2ZrUkRMMzladnV2OTAzbC9mVjBvcFBVYmtQT3o2Y2oxaWdO?= =?utf-8?B?WG1QTGl0NnBPOHJJUWpoZ3VvaG1najE1T3QwZE1wWk9MRVBtMjUxVzl5b1RQ?= =?utf-8?B?aW1QdGU1alVRMjQyVXBuaGZkc0NBdklGM1lUc25QbjhGeVFvd1UzMUdnSlRO?= =?utf-8?B?VXhXaTY5YTAxT0xUSEg0MnZ4ZTkrLzB6S0toM3dqRlIwc0NMUi9MTGdIVnBh?= =?utf-8?B?WmNwajFhQUE4ZlFxV1lXUmRtaGdNRGIyaGxqVGJyVXc3L3pibmNlRlR6ZnU2?= =?utf-8?B?Wm82Q3VpRzNseUczM3U0bGhIZGZrbUNuSVZieWdiVXZlSlJDRXRsVXFWYjg0?= =?utf-8?B?cmYxQzNHNE4yK2dXUkNtUmE4VDR3S3NhZlAyY3pQeSt6RTg5RThTbFJTVS81?= =?utf-8?B?dmQvbTFFRUJzbUJEcG45WjZTL0ZzZmVnVXpYWkJIQVVWZHNxWnV5KzZ5YVM1?= =?utf-8?B?KzBGa0gwSmhYbWZQVnROQndwU2d5WmNUckp4bTJ5KzNmRnlCeFNXTDNaMkhN?= =?utf-8?Q?SLxtb/WWhC4cWkM/vYOUY/VKT1DZ0yEOvJgUMRf?= X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 11ccb53c-e521-4a2a-cf69-08d8d9d6644a X-MS-Exchange-CrossTenant-AuthSource: BY5PR10MB4196.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 25 Feb 2021 21:43:30.8210 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: EgXbi3Cbs7yx/TB9LJHmpKH010QYi+g4Xf05n42Rv91hCp66DhsWiEtNHhN5W4ZNRBRQ+/Rm3tktR5ih+AhZyg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR10MB2823 X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9906 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=0 malwarescore=0 mlxlogscore=991 adultscore=0 bulkscore=0 mlxscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2102250163 X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9906 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 phishscore=0 malwarescore=0 spamscore=0 mlxscore=0 suspectscore=0 priorityscore=1501 clxscore=1015 impostorscore=0 lowpriorityscore=0 mlxlogscore=999 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2102250163 X-Stat-Signature: j4xggarhc1w11pqxhrjjs1eoh7ntbdwo X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: A023AE7 Received-SPF: none (oracle.com>: No applicable sender policy available) receiver=imf20; identity=mailfrom; envelope-from=""; helo=userp2120.oracle.com; client-ip=156.151.31.85 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614289418-183134 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: On 2/10/21 12:23 AM, David Hildenbrand wrote: > On 08.02.21 11:38, Oscar Salvador wrote: >> --- a/mm/compaction.c >> +++ b/mm/compaction.c >> @@ -952,6 +952,17 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, >> low_pfn += compound_nr(page) - 1; >> goto isolate_success_no_list; >> } >> + } else { > > } else if (alloc_and_dissolve_huge_page(page))) { > > ... > >> + /* >> + * Free hugetlb page. Allocate a new one and >> + * dissolve this is if succeed. >> + */ >> + if (alloc_and_dissolve_huge_page(page)) { >> + unsigned long order = buddy_order_unsafe(page); >> + >> + low_pfn += (1UL << order) - 1; >> + continue; >> + } > > > > Note that there is a very ugly corner case we will have to handle gracefully (I think also in patch #1): > > Assume you allocated a gigantic page (and assume that we are not using CMA for gigantic pages for simplicity). Assume you want to allocate another one. alloc_pool_huge_page()->...->alloc_contig_pages() will stumble over the first allocated page. It will try to alloc_and_dissolve_huge_page() the existing gigantic page. To do that, it will alloc_pool_huge_page()->...->alloc_contig_pages() ... and so on. Bad. > Sorry for resurrecting an old thread. While looking at V3 of these patches, I was exploring all the calling sequences looking for races and other issues. It 'may' be that the issue about infinitely allocating and freeing gigantic pages may not be an issue. Of course, I could be mistaken. Here is my reasoning: alloc_and_dissolve_huge_page (now isolate_or_dissolve_huge_page) will be called from __alloc_contig_migrate_range() within alloc_contig_range(). Before calling __alloc_contig_migrate_range, we call start_isolate_page_range to isolate all page blocks in the range. Because all the page blocks in the range are isolated, another invocation of alloc_contig_range will not operate on any part of that range. See the comments for start_isolate_page_range or commit 2c7452a075d4. So, when start_isolate_page_range goes to allocate another gigantic page it will never notice/operate on the existing gigantic page. Again, this is confusing and I might be missing something. In any case, I agree that gigantic pages are tricky and we should leave them out of the discussion for now. We can rethink this later if necessary. -- Mike Kravetz