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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38D47EC874D for ; Thu, 7 Sep 2023 18:39:21 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8AB398E0001; Thu, 7 Sep 2023 14:39:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 85AFF8D0002; Thu, 7 Sep 2023 14:39:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 65F5B8E0001; Thu, 7 Sep 2023 14:39:20 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 4ECCC8D0002 for ; Thu, 7 Sep 2023 14:39:20 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 213DF1CACE1 for ; Thu, 7 Sep 2023 18:39:20 +0000 (UTC) X-FDA: 81210664080.27.26017E2 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by imf03.hostedemail.com (Postfix) with ESMTP id C92012001E for ; Thu, 7 Sep 2023 18:39:16 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-03-30 header.b=NMvJDLaF; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=qPkr0E2I; dmarc=pass (policy=none) header.from=oracle.com; arc=pass ("microsoft.com:s=arcselector9901:i=1"); spf=pass (imf03.hostedemail.com: domain of mike.kravetz@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=mike.kravetz@oracle.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1694111957; h=from:from:sender: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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ejS1mAkoM4KCZEWFqQfdXK4z8VDZe/OZfJZfVsKb6N4=; b=0GQ2lEmpeOzt0wcSZTsjemNFg7cQS+oiAUmhhVIrGWOSkVOVpNouKAzti/maSBmIwNEUQ9 qYyaxmi8m5dlRBvQ67Hlefj2gML/z9t4efhSmCl1SVetNf29GT8xfVEyDxmPD7xNhzSImP qH7StvqcLOBO46KisnFHRT9+l56qmO0= ARC-Authentication-Results: i=2; imf03.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-03-30 header.b=NMvJDLaF; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=qPkr0E2I; dmarc=pass (policy=none) header.from=oracle.com; arc=pass ("microsoft.com:s=arcselector9901:i=1"); spf=pass (imf03.hostedemail.com: domain of mike.kravetz@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=mike.kravetz@oracle.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1694111957; a=rsa-sha256; cv=pass; b=lrje2/lJlNcFR3AuCWvPSCa/TDmrjgKfqIDifUgsQA5pz7rTmYVfk2XIny16wwosX4UAfC v1p1e2DlWm6riYHxFX46oRcCz2IPjVErIJy/NG+6xMAkhhcH+YDVpvFNWBHzlmRLCFQIjW tub9fJyDL1zSN7dIv8gBJMbsN3zokng= Received: from pps.filterd (m0246617.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 387IF3W5014152; Thu, 7 Sep 2023 18:38:51 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : content-type : in-reply-to : mime-version; s=corp-2023-03-30; bh=ejS1mAkoM4KCZEWFqQfdXK4z8VDZe/OZfJZfVsKb6N4=; b=NMvJDLaFXMjB8l6gb7zkP0etM9r5CeWmXSvbtWyKIooZWSb6fuzlh9vxlmU7Cp1fmF/l ioTuuSw7vuk3E023E/iNmJ6iZiKB5doR6c+ucFvAVQ+MRXUiukBFGIrjhXnsQCRWKXQm I+DOY9LjAt0SYG9C2DV4F8xYDcyTVPT8I6aPSgWdB2zgQS2mm80gEFRR3V3X3mkQbJO0 8uipbbRzjetaalSxetLt8l3hPRBUIkxFuokLfHQTp9DWik8PzmjtWLda5Vu6VOw87K0b xRJly1ucP3Zm9sR1kvrtBspb8zO/OyfmzlOMSOXz20nEG2he0bZtxCCg/iuiKx73dR2i mA== Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.appoci.oracle.com [138.1.37.129]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3sykmn01gs-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 07 Sep 2023 18:38:51 +0000 Received: from pps.filterd (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 387HFvlF031082; Thu, 7 Sep 2023 18:25:01 GMT Received: from nam11-dm6-obe.outbound.protection.outlook.com (mail-dm6nam11lp2177.outbound.protection.outlook.com [104.47.57.177]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 3suug8jec2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 07 Sep 2023 18:25:01 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=m0h0QdIeMpzgFXOAngpkGNR1RL/+ynDf0IAj1eXnL9462bjbgpm16PS1drlqgio3FdyR2/wj5cRSnI0jwvEXrPSIAygdKE7phFfPg31r4SROBKZ+TWjzBM5ajt+ygTEUZveu7e+shbeAIvIMPbvuYmXCS9od+WJEJd9GNfghYic9ZHPXoNEDQPiF3M2E0dLLPixUhgmv3WWslkX6a7E75W9zUJlXl+AjxpyOT8j1vGZptVrDre+zCH5uka9hNVgqR7c+it2edYtKqrXl9QTcuXXTOo7ctUMbI8ESOfk6E0PZL7ds2vhhjuJzAm74izGHV9UAMX5HGXGPZ6caZXWK7A== 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=ejS1mAkoM4KCZEWFqQfdXK4z8VDZe/OZfJZfVsKb6N4=; b=c6QQmNdtVq5lnuaKwW8DMW6CnmKEBedE23Y37KVBu/hwhmoWF2JsK7xez/PSDgWyfx+bMST4wjDjvFFg/uYuUZz23RFERD6IYbJjf+y3zlIHqHmVRtBR0xKeN4MzyssyaV9A05LAttMmDKxuwLRUm1jnzSx93JWRcFELckaoDo6P3+vtVupNZKqrVcZy3CNCYpcacQuVO+L8O+ClG/vPeF8GVfC8J7+SPudv4GGRqXFNfftIPFdfOPQWUPbZlwR90y79zjiSWjh+FRQIEMO/w/1KtuaDK3zhVQWQFP9cWoxDlBjLBhbL6aeAy4mQ49Bta7+/RQgnAzICxN43FRZiNw== 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=ejS1mAkoM4KCZEWFqQfdXK4z8VDZe/OZfJZfVsKb6N4=; b=qPkr0E2IyyXBXep1sfCCjOMjCTnphPtpHOslKhg6gVqz64Z7EHszki0fbCCJ5/fRzTGgpmuHhwgO73dOENf6Jpr06EkuJW5/rM/wkrLR3py46tte80r1snwC8dx70QKjC6ic9cT2K26X4ba9M3sK++A0bZZ0sBgOySaWbjmQuF4= Received: from BY5PR10MB4196.namprd10.prod.outlook.com (2603:10b6:a03:20d::23) by BN0PR10MB5205.namprd10.prod.outlook.com (2603:10b6:408:116::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6745.36; Thu, 7 Sep 2023 18:24:58 +0000 Received: from BY5PR10MB4196.namprd10.prod.outlook.com ([fe80::c621:12ca:ba40:9054]) by BY5PR10MB4196.namprd10.prod.outlook.com ([fe80::c621:12ca:ba40:9054%4]) with mapi id 15.20.6745.035; Thu, 7 Sep 2023 18:24:58 +0000 Date: Thu, 7 Sep 2023 11:24:56 -0700 From: Mike Kravetz To: Usama Arif Cc: linux-mm@kvack.org, muchun.song@linux.dev, rppt@kernel.org, linux-kernel@vger.kernel.org, songmuchun@bytedance.com, fam.zheng@bytedance.com, liangma@liangbit.com, punit.agrawal@bytedance.com Subject: Re: [External] Re: [v4 4/4] mm: hugetlb: Skip initialization of gigantic tail struct pages if freed by HVO Message-ID: <20230907182456.GA3640@monkey> References: <20230906112605.2286994-1-usama.arif@bytedance.com> <20230906112605.2286994-5-usama.arif@bytedance.com> <20230906181016.GA3612@monkey> <57c8dd7f-d1a0-37c4-1d3b-d6374e92ffa1@bytedance.com> <20230906215927.GE3612@monkey> <92fc88ba-3e3a-2648-4232-1d3f9bed5bb6@bytedance.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <92fc88ba-3e3a-2648-4232-1d3f9bed5bb6@bytedance.com> X-ClientProxiedBy: SJ0PR03CA0040.namprd03.prod.outlook.com (2603:10b6:a03:33e::15) To BY5PR10MB4196.namprd10.prod.outlook.com (2603:10b6:a03:20d::23) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BY5PR10MB4196:EE_|BN0PR10MB5205:EE_ X-MS-Office365-Filtering-Correlation-Id: 10beb58b-8bb7-429a-df47-08dbafcfbdc8 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: bMgEl2gyOUBWXyG8KDxmLC9k9NhvT1ILCzSSx6wZ1Z/6ZQpwaB21fa/isqE4DueHsbDsldF1wcPvCKtRjyPAOo3v6lpxQNQnFJBJ8BCKFe4RlgE28iZQ9ezctTzjPxhOTqUjSAalGooMTOlLRvVPIQQpCN7UFLgUNEZHbosdGN0ZQJNfzWdjw9s9aCuITITBUuWEaVo5IRA0J0Zyfy/wYD+FfvWLCNcuriTj0TeEqcF58WyjIC7XKsZPekt/KMRMHfE7aD8aoooViBaOgJRgxz+k60t8PbEMlzkcF3wMU8Wn8J4TeQZ+aJ+I4e6s7lyCWbxkCTsh6yC/+0Mdoj1YDm4OB97WRHCQ4EjwKMSg8jdR2TLsX56vIW+ws7Jpvyy4fQUziQv/kcjaaxgXKcdHSTK1JgJYQ2Ff3Zpcqr5A8I6QSWMIsvTaZDbvNrZYUkV02gpR7iGEbfO7KIPN0uzIzDVm4x0zCiQRiay3exHCMPrhZsOtaU55Zo8xqZG2N9ezWAlH9vhFgaUVtakopBPEKy5U3W46lbj6SgJSv7djfULNpHfPU5p+RTH9kVs+djg2Xjg2BN+i+BO1HjGrDHDFmg== 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:(13230031)(7916004)(346002)(376002)(136003)(366004)(39860400002)(396003)(186009)(451199024)(1800799009)(6916009)(316002)(66946007)(66476007)(66556008)(41300700001)(478600001)(966005)(33716001)(38100700002)(2906002)(86362001)(44832011)(5660300002)(4326008)(8676002)(8936002)(33656002)(26005)(6506007)(6486002)(6512007)(53546011)(9686003)(83380400001)(1076003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?Gl4y3vt38NCpPJgvxqFjq9yX7/XvHZ/tcgxtBnuf7izQW674t7Bqt5iWQLn8?= =?us-ascii?Q?F+93R6NDWb+l03q9HuAHCDdGsWU/THJqbF/Dnmqwil6QeNkNG24QWEvYRYWu?= =?us-ascii?Q?zh3oIaqalL2TobuobUmUMxZqvo6ap3eSl3IYkb+6ataucCOn5qJQJfm1odKM?= =?us-ascii?Q?QSKNtcC24V1YxGK/j9L+TbTAeVpedSJrpgi2kOG9ocXKptss+ARTckAPK/xl?= =?us-ascii?Q?NVA8rvzqgnhL8sJ6vsz5MgYYPXw1Q7nmlEg7UfGKSmBHXoNDnzbC+r9iaNdy?= =?us-ascii?Q?SC4njCErb9XKgvoSdThJxK0MOFUzmTssyi/Glzt1zbTgUDMICq0j0rv+31kb?= =?us-ascii?Q?xkyCNskjN9DVvu4IIqDI+F+6sxPyHWo40F+dmwyTKIo+ngqguTsL/1Dhp1zr?= =?us-ascii?Q?u6w3R9sp6GaRU+pvDm7t6Ai2SSSgj1+0+lUHqi0W2CW3eiwFk8awKMfLNCIh?= =?us-ascii?Q?9bv2nOWLJpuXeDW4D3nUh5e6Qcs9OcR2xPZ1S+Xmme0hHNMpmFT3FBpiVvFW?= =?us-ascii?Q?67OwcP113XGru4OEkchrIz9OgY1rOCgk11wyTKskseJQSso6vYfM0bxYLYUq?= =?us-ascii?Q?3gf0JkyTxffO15uFzc/3iGbosdezvoTG4A1DhMK3gaY9a6rzBB4LYK0GHnsW?= =?us-ascii?Q?zFQ/XZFtgDpY8OvJz/ANQOcPJOHEAjsrkYDh95ROqkaebjQ948VtkjeTSrs2?= =?us-ascii?Q?fIJs+5r14XjYaBr0kpBCN+3LxxDzwq5ifpbtV9YzNVqOdjaVtuZMhL7/l5H9?= =?us-ascii?Q?M/NPWhFTvccn1rJMulyGmYeBd+hBxVCMKjDI03psWdVdgRljtsjTKqBEJLbb?= =?us-ascii?Q?3kXpQmC4zX6ROpFltUBP+Qe9YrH/aNnWYb1HbG0QXFuSyR8r+HS+wIm5eM17?= =?us-ascii?Q?94blIMF2/ikUlDsicOvLl32/2l4cu4gNN+oKMNWr2TKrZjPH1o+SJtfVpXAt?= =?us-ascii?Q?xyTLhBMsOMaECnS+JH3A+ekLaAQS5cQpy1LqSVVVhf6uEPHbq3XbvWiNeQ2I?= =?us-ascii?Q?ldRHleqjs7jW2Miph5DrrLQcXHGE8gHYtrXs6Zu5N5wM2cl5rBWCcZolGZQK?= =?us-ascii?Q?PNI4XowgQGj7JN6nimn6hbPFPUKZgef3vzVcWySfcRz+3RYSgBVlKus/GzMn?= =?us-ascii?Q?t3vuk2CwVJujiRtePq1Dl7AFC2uz7zwHJfAOu3OupkNDe1bqslkDwDzdZ1Pa?= =?us-ascii?Q?GK+Dj57NGCoI2s6JZ45PmxpglxhGaPokYh/g7xRDPL7mIrTrfTJYova8t+LG?= =?us-ascii?Q?B+sA4xKoHnmy7bDC7LzsFt/frr41avLFKuObj4TaWhjkOlN/RYeKjLK4w3wP?= =?us-ascii?Q?tdnJbZpD07R1+i2VKJcUTpbvetkvTADnedeiwkizCCjyG7WdzHkj7hCqN7oe?= =?us-ascii?Q?alWo7Mwa1OkgvVfYJ9UzHmYcW1XB/SPZMpDMPSJyQ/+YovoqXtdw7IKdcc/T?= =?us-ascii?Q?fecZ7+h60mmuJidtTUVPgyG+zH1BYy+97OqfORYbg6Cxuxe44nQd16L5o15k?= =?us-ascii?Q?tkwqaVX/HrR5WoDFCnQjtVTk+wNUFO9j5XdViu8yzTUYkSWePutaFlWX7W8n?= =?us-ascii?Q?rrE9H5qN9hkfybKDnAhLbmeqEHLs9szbic2hSilM2setvAT+Z9Mc3rXt/xDS?= =?us-ascii?Q?xQ=3D=3D?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 10beb58b-8bb7-429a-df47-08dbafcfbdc8 X-MS-Exchange-CrossTenant-AuthSource: BY5PR10MB4196.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Sep 2023 18:24:58.3333 (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: 5xvEvrAX6KWLqMq0ziz8T2Z3vNt19xmeYUt4ZiGIPwEGYFa+5FjjOYIqkVCXuUkaVmHLnkueTi8IqKRd0i5QWA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN0PR10MB5205 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.267,Aquarius:18.0.957,Hydra:6.0.601,FMLib:17.11.176.26 definitions=2023-09-07_10,2023-09-05_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 phishscore=0 bulkscore=0 adultscore=0 suspectscore=0 malwarescore=0 spamscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2308100000 definitions=main-2309070162 X-Proofpoint-GUID: HC-caxKN6EK7ZhmkgxnaDUT5QbQ2l4aM X-Proofpoint-ORIG-GUID: HC-caxKN6EK7ZhmkgxnaDUT5QbQ2l4aM X-Rspam-User: X-Stat-Signature: gxn1zemkt41tk9j75yxia6x3csnhn6iw X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: C92012001E X-HE-Tag: 1694111956-386389 X-HE-Meta: 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 GmW+u9Vz 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 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 09/07/23 11:14, Usama Arif wrote: > > > On 06/09/2023 22:59, Mike Kravetz wrote: > > On 09/06/23 22:27, Usama Arif wrote: > > > > > > > > > On 06/09/2023 19:10, Mike Kravetz wrote: > > > > On 09/06/23 12:26, Usama Arif wrote: > > > > > The new boot flow when it comes to initialization of gigantic pages > > > > > is as follows: > > > > > - At boot time, for a gigantic page during __alloc_bootmem_hugepage, > > > > > the region after the first struct page is marked as noinit. > > > > > - This results in only the first struct page to be > > > > > initialized in reserve_bootmem_region. As the tail struct pages are > > > > > not initialized at this point, there can be a significant saving > > > > > in boot time if HVO succeeds later on. > > > > > - Later on in the boot, the head page is prepped and the first > > > > > HUGETLB_VMEMMAP_RESERVE_SIZE / sizeof(struct page) - 1 tail struct pages > > > > > are initialized. > > > > > - HVO is attempted. If it is not successful, then the rest of the > > > > > tail struct pages are initialized. If it is successful, no more > > > > > tail struct pages need to be initialized saving significant boot time. > > > > > > > > Code looks reasonable. Quick question. > > > > > > > > On systems where HVO is disabled, we will still go through this new boot > > > > flow and init hugetlb tail pages later in boot (gather_bootmem_prealloc). > > > > Correct? > > > > If yes, will there be a noticeable change in performance from the current > > > > flow with HVO disabled? My concern would be allocating a large number of > > > > gigantic pages at boot (TB or more). > > > > > > > > > > Thanks for the review. > > > > > > The patch moves the initialization of struct pages backing hugepage from > > > reserve_bootmem_region to a bit later on in the boot to > > > gather_bootmem_prealloc. When HVO is disabled, there will be no difference > > > in time taken to boot with or without this patch series, as 262144 struct > > > pages per gigantic page (for x86) are still going to be initialized, just in > > > a different place. > > > > I seem to recall that 'normal' deferred struct page initialization was > > done in parallel as the result of these series: > > https://lore.kernel.org/linux-mm/20171013173214.27300-1-pasha.tatashin@oracle.com/ > > https://lore.kernel.org/linux-mm/20200527173608.2885243-1-daniel.m.jordan@oracle.com/#t > > and perhaps others. > > > > My thought is that we lose that parallel initialization when it is being > > done as part of hugetlb fall back initialization. > > > > Does that make sense? Or am I missing something? I do not have any proof > > that things will be slower. That is just something I was thinking about. > > The patches for deferring struct page initialization did not cover the > struct pages for gigantic pages. > > With CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled, the function call taken > during boot without these patches is: > > [A1] mm_core_init-> mem_init-> memblock_free_all-> > free_low_memory_core_early-> memmap_init_reserved_pages-> > reserve_bootmem_region-> initialize *all* struct pages of a gigantic page > serially (DEFERRED_STRUCT_PAGE_INIT is enabled). > The pfn of the struct pages > NODE_DATA(nid)->first_deferred_pfn which means > this cannot be deferred. Thank you very much! I am not very familiar with the init process and just wanted to make sure that no possible performance regression was introduced. In will make some specific comments on the patch, but as previously stated it looks pretty good. -- Mike Kravetz > then later on in the boot: > > [A2] hugetlb_init-> gather_bootmem_prealloc-> prep_compound_gigantic_folio-> > prepare *all* the struct pages to be part of a gigantic page (freezing page > ref count, setting compound head, etc for all struct pages) > > With CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled, the function call taken > during boot with these patches is: > > [B1] mm_core_init->...reserve_bootmem_region-> initialize head struct page > only. > > then later on in the boot: > > [B2] hugetlb_init-> gather_bootmem_prealloc-> [B21] initialize only 64 tail > struct pages if HVO passes. [B22] If HVO fails initialize all tail struct > pages. > > > Each of A1, A2 and B22 are for loops going over 262144 struct pages per > hugepage. So without these patches, the work done is 262144*2 (A1+A2) per > hugepage during boot, even with CONFIG_DEFERRED_STRUCT_PAGE_INIT as its not > deferred. With these patches, the work done is either 1 + 64 (B1+B21) if HVO > is enabled or 1 + 262144 (B1+B22) if HVO is disabled. > > With CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled, the times taken to boot till > init process when allocating 500 1G hugeppages are: > - with these patches, HVO enabled: 1.32 seconds [B1 + B21] > - with patches, HVO disabled: 2.15 seconds [B1 + B22] > - without patches, HVO enabled: 3.90 seconds [A1 + A2 + HVO] > - without patches, HVO disabled: 3.58 seconds [A1 + A2]