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=-12.3 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 6DB1BC433DB for ; Wed, 24 Mar 2021 01:03:56 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id AEC53619A3 for ; Wed, 24 Mar 2021 01:03:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AEC53619A3 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 2C4E06B01F0; Tue, 23 Mar 2021 21:03:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 275596B01F1; Tue, 23 Mar 2021 21:03:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 079E26B01F2; Tue, 23 Mar 2021 21:03:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id E0D396B01F0 for ; Tue, 23 Mar 2021 21:03:54 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 966678249980 for ; Wed, 24 Mar 2021 01:03:54 +0000 (UTC) X-FDA: 77952970788.02.6148812 Received: from userp2130.oracle.com (userp2130.oracle.com [156.151.31.86]) by imf07.hostedemail.com (Postfix) with ESMTP id 544B6A0009DE for ; Wed, 24 Mar 2021 01:03:53 +0000 (UTC) Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 12O111Jm094122; Wed, 24 Mar 2021 01:03:13 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=DusIZ7MOyMBSHHvglBHjkPuke97odDGyoVt32sqW0hg=; b=Du/dgbX6ypYl6ta/aq4bz7rhiNlS0E1gxPDFBn9oHtOSX9hxBBhz9+T6QXazKnG5ikGe l4+mcC3DE9r8q2ATvtrIE4NtY6W2ZVasuzJhIYdCYbJOW8JLQL9hp4BmGcI0YLO+L8Gf CRQPcPs2cx7NCsYC3Yiy5JR1Dw0OZsoVmPapa+uZ7KP+tZN3EVAUBOUPvYSwuzADpNTa IePXuYRDTC4F7bihcAuxe0IbEyyCXGMYbAf977OuMV5xRx+k/YIYwBAKAW1nO6X6Dt6r e3PCecG348D3NhQsfI1iPs2wvE3ZfCayqsIDojv23ZMe8rx4DaN0Kqljyp0pnPXI1yBz QQ== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2130.oracle.com with ESMTP id 37d8fr93q0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 24 Mar 2021 01:03:12 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 12O10lN3152859; Wed, 24 Mar 2021 01:03:12 GMT Received: from nam11-dm6-obe.outbound.protection.outlook.com (mail-dm6nam11lp2171.outbound.protection.outlook.com [104.47.57.171]) by userp3030.oracle.com with ESMTP id 37dtyy6ct7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 24 Mar 2021 01:03:12 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Zk0jiQMJiqVmvmpu5PaSP9F2m6De8er1korLeA5SH33fGUNn2WfJPMFW5E3lTOxLsBgLmswuyJHb2bUUx8AMDTKSbc8XUREaQLn7az3euHqBsbTOlVnheaxlB16tFosrekCQm/SpVMWz8g4o1A433f5pkBu05G+ONzTBdeK0Q5PqtYSS7JKvkPEO5ipSeiEYbMnLHyew3ApRtpuOv+wJ7/xr8xrGFZejUxpDwsDsZCjIC6wQ3n7zOxq+nlS7wQLwldnZyhsYIE+LyzHZbpLucX6S56wBhLUKRWL6haecwekyWqAvmfqOumYlvnvj+Vpy7WD/G/UlRkJYeFBoUVJpUQ== 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=DusIZ7MOyMBSHHvglBHjkPuke97odDGyoVt32sqW0hg=; b=ehkY38c42aOA5xeiG8bj7c+WDhRxY5MUVZneRxPyscITwoj++5uZpMXDmWAjlYxxBPNk/2ZQ2QwG7LZv3dYKoLWkfo+dLcnfKSlOHAKCz9AQsBrdr5B/xJZZRmpoz/6xwqObpgSjaQXaD+1JuYQ0BFPHnn/NHWBDleV5FsM6iiLc6g4Sw/TkWW+zbe0NFF2JlMe6yl3RbwrHoPgAcgl3xjdJHKCyOdwJss/3r7vO6CcE+y7rVy/tnmpMlKsGXmYAcxvbcGjWdM14O6Rpo5udHnJZtDvq3ombFHp5iYSn7pZfK4SkLK2yHMJZwlWOMJdWbL8VpXexYtuvy88eBDI2IQ== 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=DusIZ7MOyMBSHHvglBHjkPuke97odDGyoVt32sqW0hg=; b=ThNF8zSqAwk9ahJW+Jsb/KseWLWbQ38JzaBcUBdVFqGVCwNdjeJd9fXVtQHqwqHw3XH3jRUQ+mKjp5zdiWXZRAjraa/IViatolgXwpeF4Uwa14OujgM9niQjhiV0Tq/tv43G/7DFQUfGIefWU9UYLbvEx19yF2elc7y3ioCxZC4= Authentication-Results: linux-foundation.org; dkim=none (message not signed) header.d=none;linux-foundation.org; dmarc=none action=none header.from=oracle.com; Received: from BY5PR10MB4196.namprd10.prod.outlook.com (2603:10b6:a03:20d::23) by SJ0PR10MB4590.namprd10.prod.outlook.com (2603:10b6:a03:2d1::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3955.18; Wed, 24 Mar 2021 01:03:10 +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 15.20.3955.027; Wed, 24 Mar 2021 01:03:10 +0000 Subject: Re: [RFC PATCH 5/8] hugetlb: change free_pool_huge_page to remove_pool_huge_page To: Michal Hocko Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Shakeel Butt , Oscar Salvador , David Hildenbrand , Muchun Song , David Rientjes , Miaohe Lin , Peter Zijlstra , Matthew Wilcox , HORIGUCHI NAOYA , "Aneesh Kumar K . V" , Waiman Long , Peter Xu , Mina Almasry , Andrew Morton References: <20210319224209.150047-1-mike.kravetz@oracle.com> <20210319224209.150047-6-mike.kravetz@oracle.com> From: Mike Kravetz Message-ID: Date: Tue, 23 Mar 2021 18:03:07 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [50.38.35.18] X-ClientProxiedBy: MW4PR04CA0139.namprd04.prod.outlook.com (2603:10b6:303:84::24) 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 MW4PR04CA0139.namprd04.prod.outlook.com (2603:10b6:303:84::24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3955.18 via Frontend Transport; Wed, 24 Mar 2021 01:03:09 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 4ea0c2f7-4894-446c-c168-08d8ee60979b X-MS-TrafficTypeDiagnostic: SJ0PR10MB4590: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:741; 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:(346002)(366004)(396003)(39860400002)(376002)(136003)(31696002)(16526019)(186003)(6916009)(54906003)(8936002)(31686004)(83380400001)(16576012)(53546011)(5660300002)(66476007)(26005)(66556008)(478600001)(316002)(36756003)(66946007)(52116002)(6486002)(7416002)(38100700001)(44832011)(956004)(8676002)(2906002)(86362001)(2616005)(4326008)(14583001)(43740500002)(45980500001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData: =?utf-8?B?OU9iaFdpNWJmQnpOOUo3ZnY4ZGpEbWpZRU5sOEQ3N2VsSTZxb0c5Q3NuVHVz?= =?utf-8?B?NjZCL3VTdldsaEdROTFPeWpweWZuUjFQQWtsajBnaFFYR0FMeGMxbm5vbUR5?= =?utf-8?B?a3VKanZQbGtScWZITkV1eDJhUFRrUzkyT0paQWd6U01lenFEamJFY09tNVhW?= =?utf-8?B?NDYvY200b1lBSjBzaG5jUU1EYjJ0ZzFiVnVQRzJRQUJndW9tOVp2djRKYzhr?= =?utf-8?B?c0ZBV0x6WkZ2cUhJM0RjNFFTK2NnYlg2bW1mL2V0N2owb1VGbTZ2encyR25S?= =?utf-8?B?Ly8wS2JZSjlLd1pxT3F6VkhaM1lqRDRITW9BZGlsK3E3YTB4WS9XNkhaYS9Y?= =?utf-8?B?K0p0RnJOcDVFZTJ5VHdVTzB4VHhmZDcvNFNMMWJ6dm5qNy9rL0IyR2hyWjBU?= =?utf-8?B?THFWYW5FYTVqbXoxRjYyekpWQVNDVkhRYTJVeVZGdzA0M3hoVWJ5dWMwTzRJ?= =?utf-8?B?YzdTZ2l0c21oWWhmVWo1ZTNZZFZzR2grTVNjL1NNbUhPK0FhWklGRyt0Z1dU?= =?utf-8?B?ZVhWOElYaTZTNnJFUVFjZE01UU85alBLd0ZKWlhORUxCcFZlbnNzeUJmKzNU?= =?utf-8?B?WVdLWXdJR293YnRnNU1mWnlSZTNqcytvakd2bWJCRUZjcHlFMTg5WVhWcmNL?= =?utf-8?B?NkZvZ0VjeTJ2Z0VIWWZkWWo2VjRLalhYT3ZFRnJ4aEYzbFFzVU00dzBnZFBt?= =?utf-8?B?WEJIT21zS2tYVnIwdmtJVG80MytyZEc5eGhTVitRa095MkZCcUNDT1FZM2x0?= =?utf-8?B?L2VGY2VxWHFEeTNxbkRqK1JBR0cvR2hUYkZENHprby90V1VqS21QbnRtNStQ?= =?utf-8?B?ZTdndUxoYmhpY3EvZVdjRktWemRCSlFha0R6QlZDK0FBQVVuRXpXOEo0czVC?= =?utf-8?B?UTkzMUR5VFVERmtTMDFWTUtBY0dOTVlrOE5RYjlyY25URnFQWWdodFBLd0pR?= =?utf-8?B?N3crZTgzN0dTZVV2c3pvNWZvSFVjWFdRNzRFVTlnMmw4dmx0Q0hLTnJZbGpN?= =?utf-8?B?dEZRWkkyRHM0NCtyUDNtMnhMdGtTU0doNGJkeGIya2JUdWJvdHYrdFNZajVH?= =?utf-8?B?NWh0cHlVUVg0VDBnMjlEVmRhRmdQaG0rVVFGeHRHUi9LUnc1THB3dWc3Q3Ny?= =?utf-8?B?dldEWVNtOHRmakhpMnEyeklxZlJFd3VEUzBKS0NRQkhKVWVEYklXNzZaT2Zy?= =?utf-8?B?K3hxVXVVQnNyY25UeEhrUlZybmFWSG4wWUpJb2FPTmwyUjc5Njg3RWtrbmho?= =?utf-8?B?dGZwNkdvMis5aDd5cXBJaEozRlliM0xtS3dtdnE3aUhTR0RORHZsVTdPYWFC?= =?utf-8?B?cFozL0t0VzRUaG5acHdKU2FpYkZrRUtrTXM3RlRlMG9ka1B0cTVoalRMc3Iw?= =?utf-8?B?bWtwZzhwZlJtWkx5Ui8ybnlETEFHUW5iTHdwRDZVTzFaUHNNcDNZTlhQdDh2?= =?utf-8?B?TFU5dXQ3SHNlU1pDYWpUUGNaQXNzS3krN2lTRGtMc0lsV2xJQjdPL01KREQr?= =?utf-8?B?U3V0RHlpaE56dGRCbk9EeE1LVXNiODRhVEh6T2tQQkRCMm05UFlmSkkzaWps?= =?utf-8?B?cWtiRjZhblNMUlN0dTVaQWdqdm5DWkpueFVKMnNwSHVxSUJmRm1keDhQSHA3?= =?utf-8?B?Y2FsUnNtRXM1NVc0SHhvd1lpQ1Z5R2JVS0NULy85TGo3akpUQTNhS3hjWGd4?= =?utf-8?B?dE1nYmZScUVZL1ZJckdrNG1NN0tGenVWc1I2WFgzREFlNzI2N1NOekd3UEdZ?= =?utf-8?Q?Yr13a4svXS/paDRTVUnKNMBO/JmzrT8U3/b7vaL?= X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 4ea0c2f7-4894-446c-c168-08d8ee60979b X-MS-Exchange-CrossTenant-AuthSource: BY5PR10MB4196.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 24 Mar 2021 01:03:10.2306 (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: ia9TQZIZoo37QPPol8Ao4aHr4oFQ0aiqCxf3hG5M1AXOqZC2eDo5n9A8Yvlw70/TtB0Y19yXF+AJwF7qHLwhuQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR10MB4590 X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9932 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 bulkscore=0 phishscore=0 mlxlogscore=999 suspectscore=0 spamscore=0 malwarescore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2103240004 X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9932 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 lowpriorityscore=0 priorityscore=1501 impostorscore=0 spamscore=0 mlxscore=0 suspectscore=0 mlxlogscore=999 phishscore=0 bulkscore=0 adultscore=0 malwarescore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2103240004 X-Stat-Signature: tgwakb9zpa34jjebpcjhncihnigjmr4t X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 544B6A0009DE Received-SPF: none (oracle.com>: No applicable sender policy available) receiver=imf07; identity=mailfrom; envelope-from=""; helo=userp2130.oracle.com; client-ip=156.151.31.86 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1616547833-405837 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 3/23/21 12:57 AM, Michal Hocko wrote: > On Mon 22-03-21 16:28:07, Mike Kravetz wrote: >> On 3/22/21 7:31 AM, Michal Hocko wrote: >>> On Fri 19-03-21 15:42:06, Mike Kravetz wrote: >>> [...] >>>> @@ -2090,9 +2084,15 @@ static void return_unused_surplus_pages(struct hstate *h, >>>> while (nr_pages--) { >>>> h->resv_huge_pages--; >>>> unused_resv_pages--; >>>> - if (!free_pool_huge_page(h, &node_states[N_MEMORY], 1)) >>>> + page = remove_pool_huge_page(h, &node_states[N_MEMORY], 1); >>>> + if (!page) >>>> goto out; >>>> - cond_resched_lock(&hugetlb_lock); >>>> + >>>> + /* Drop lock and free page to buddy as it could sleep */ >>>> + spin_unlock(&hugetlb_lock); >>>> + update_and_free_page(h, page); >>>> + cond_resched(); >>>> + spin_lock(&hugetlb_lock); >>>> } >>>> >>>> out: >>> >>> This is likely a matter of taste but the repeated pattern of unlock, >>> update_and_free_page, cond_resched and lock seems rather clumsy. >>> Would it be slightly better/nicer to remove_pool_huge_page into a >>> list_head under a single lock invocation and then free up the whole lot >>> after the lock is dropped? >> >> Yes, we can certainly do that. >> One downside I see is that the list can contain a bunch of pages not >> accounted for in hugetlb and not free in buddy (or cma). Ideally, we >> would want to keep those in sync if possible. Also, the commit that >> added the cond_resched talked about freeing up 12 TB worth of huge pages >> and it holding the lock for 150 seconds. The new code is not holding >> the lock while calling free to buddy, but I wonder how long it would >> take to remove 12 TB worth of huge pages and add them to a separate list? > > Well, the remove_pool_huge_page is just a accounting part and that > should be pretty invisible even when the number of pages is large. The > lockless nature (from hugetlb POV) of the final page release is the > heavy weight operation and whether you do it in chunks or in a single go > (with cond_resched) should be visible either. We already do the same > thing when uncharging memcg pages (mem_cgroup_uncharge_list). > > So I would agree with you that this would be a much bigger problem if > both the hugetlb and freeing path were equally heavy weight and the > delay between first pages uncaccounted and freed would be noticeable. > > But I do not want to push for this. I just hated the hugetlb_lock dances > as this is ugly and repetitive pattern. As you may have seen in my reply to patch 3, I am going to use this batching approach for all places we do remove/free hugetlb page. Since you brought up cgroups ... what is your opinion on lock hold time in hugetlb_cgroup_css_offline? We could potentially be calling hugetlb_cgroup_move_parent for every hugetlb page while holding the lock with interrupts disabled. -- Mike Kravetz