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 9D877C36010 for ; Mon, 7 Apr 2025 14:23:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CAE2E6B0007; Mon, 7 Apr 2025 10:23:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C83636B0008; Mon, 7 Apr 2025 10:23:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AFC466B000A; Mon, 7 Apr 2025 10:23:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 8E2FA6B0007 for ; Mon, 7 Apr 2025 10:23:32 -0400 (EDT) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 211BFBA79F for ; Mon, 7 Apr 2025 14:23:33 +0000 (UTC) X-FDA: 83307465906.17.D718716 Received: from NAM04-MW2-obe.outbound.protection.outlook.com (mail-mw2nam04on2079.outbound.protection.outlook.com [40.107.101.79]) by imf02.hostedemail.com (Postfix) with ESMTP id 54F5380002 for ; Mon, 7 Apr 2025 14:23:30 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=iHXGVBYa; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf02.hostedemail.com: domain of jgg@nvidia.com designates 40.107.101.79 as permitted sender) smtp.mailfrom=jgg@nvidia.com; dmarc=pass (policy=reject) header.from=nvidia.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1744035810; 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=geGb3jek7KlIMIbcLWTLWaSu94BBbGctjeal72k8Nbk=; b=4aels71jneLq8hTAn4siNCtN/BxPOeTuM4VBuX8YGSp+JUnjYAI71lCNWUw9TglFJbI/qS nSgsk5jPrybDSV5YchnUgjQPupqLVz1221F3Kp4pTeZNRPhTJ4eRfXtvhSTTl9rRb2nLjB J1B4/Ku1AK72IPO3TJDANSqdmhWp5fc= ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1744035810; a=rsa-sha256; cv=pass; b=bb1bF2XjALzOEFZqWT3EKTdAIxy//buRm0mFsfYjjrZi5WFq1ORIYl0V18OsYUKsLb0s+Q U0beVg515Fn4hpfHhpxhAV6OAxoIjSlVogDqE8KlFGyHE0eaLkzw9JAR3/9WbHQ+nx3o5V FN53gERgSc0AXi27czvvZdMrDNBrIm8= ARC-Authentication-Results: i=2; imf02.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=iHXGVBYa; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf02.hostedemail.com: domain of jgg@nvidia.com designates 40.107.101.79 as permitted sender) smtp.mailfrom=jgg@nvidia.com; dmarc=pass (policy=reject) header.from=nvidia.com ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=tIBm8Ya0P/NJf6/oRFLlI77vh10pTgdpziP9loW9XysNrdSP9MyxN7oNAscYyC6jMU7tZStJWJcLzyPGQiG5xUIDGs1IWY4JOG5Yz2O0xNHURdCDjEO8PyCVsHk5KAz767DwJ1x5mjb2opu5h6Tpw0JGhHS6Xww6gu9dLoxMOIUStRr4lUJi7dHx8Sp7eXl2kzKpuXbj7ruqc/h4ExCn1acuMZJg6ZUprjRU1iqI1C8KTb4i3jaPPjRh+ILFVnOwsNDEY9OObdTPkHa3r6YiVV/TweWF6KJB5tHuuSpX8ps4wwSZYiznc3970MWNS5wmaAjGSCCrrApNFYfQFAoilQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=geGb3jek7KlIMIbcLWTLWaSu94BBbGctjeal72k8Nbk=; b=bXxxYpCSFC6V9sMuDkRe9eVd9WSObhnM67kl4q5TMYM394Q0/nn3KwGTEil+14C0bcgKCL1do0iBeqyOmESHHE1IoAxEfDuDz2rOMMoregRP00b90byibZswo2IyPcPw56ByI3Ry81kYHUsEhjypn/Xf8s4DwRxBWDUZU8kT+s2Pc0jGJfXERRdTXjjYw7m/terSIVZTxGYzW5FWZjRrgSN6xEp41hGmGl1HpZtDQzXHKkwmXJrumQeQo0NwGxuznShASnpmeFj4gUyNU/BspaX5mfbwbrttqm0oUgPZgjF7JCffizNYh2Jg9xmtNPCjzgfn79W558VkQeiNvigWPA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=geGb3jek7KlIMIbcLWTLWaSu94BBbGctjeal72k8Nbk=; b=iHXGVBYa2AcscxuTQ3Yg5WvQk5lTRva7tzRoG3v6ZIZjBfbPeHbo+m6i69wtFIT2st7qW5YJei7jGeJeHh+Kyz/SVPGk+DS0/ZyV/REttu+WK/5AJGY6JgFlvcV+YWwAQbxjABSpBpoHrYOd1hmSuuBASknc398d0oSMGXdGCe0rAYgRDFZC0MO7mv4FAcBKTzBftWs780lgiNp0gcSGq/ahPVucmXb6sOk2w1IGRPJsIq3cJcEL6094hwg4V2t6ja8+ysY4TqXxLhz6f/6emA/Xo5jwY9aTYenbHVLFtnPI/W4qXbbCwtF3Sb9AgVtNybYGE99bUc1gRh9Ecfjmdw== Received: from CH3PR12MB8659.namprd12.prod.outlook.com (2603:10b6:610:17c::13) by MW4PR12MB7167.namprd12.prod.outlook.com (2603:10b6:303:225::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8606.34; Mon, 7 Apr 2025 14:23:26 +0000 Received: from CH3PR12MB8659.namprd12.prod.outlook.com ([fe80::6eb6:7d37:7b4b:1732]) by CH3PR12MB8659.namprd12.prod.outlook.com ([fe80::6eb6:7d37:7b4b:1732%4]) with mapi id 15.20.8606.028; Mon, 7 Apr 2025 14:23:26 +0000 Date: Mon, 7 Apr 2025 11:23:25 -0300 From: Jason Gunthorpe To: Mike Rapoport Cc: Pratyush Yadav , Changyuan Lyu , linux-kernel@vger.kernel.org, graf@amazon.com, akpm@linux-foundation.org, luto@kernel.org, anthony.yznaga@oracle.com, arnd@arndb.de, ashish.kalra@amd.com, benh@kernel.crashing.org, bp@alien8.de, catalin.marinas@arm.com, dave.hansen@linux.intel.com, dwmw2@infradead.org, ebiederm@xmission.com, mingo@redhat.com, jgowans@amazon.com, corbet@lwn.net, krzk@kernel.org, mark.rutland@arm.com, pbonzini@redhat.com, pasha.tatashin@soleen.com, hpa@zytor.com, peterz@infradead.org, robh+dt@kernel.org, robh@kernel.org, saravanak@google.com, skinsburskii@linux.microsoft.com, rostedt@goodmis.org, tglx@linutronix.de, thomas.lendacky@amd.com, usama.arif@bytedance.com, will@kernel.org, devicetree@vger.kernel.org, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org Subject: Re: [PATCH v5 09/16] kexec: enable KHO support for memory preservation Message-ID: <20250407142325.GD1557073@nvidia.com> References: <20250320015551.2157511-10-changyuanl@google.com> <20250403114209.GE342109@nvidia.com> <20250403142438.GF342109@nvidia.com> <20250404124729.GH342109@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: MN2PR10CA0005.namprd10.prod.outlook.com (2603:10b6:208:120::18) To CH3PR12MB8659.namprd12.prod.outlook.com (2603:10b6:610:17c::13) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH3PR12MB8659:EE_|MW4PR12MB7167:EE_ X-MS-Office365-Filtering-Correlation-Id: 2211a832-49a5-4542-84e9-08dd75dfc2c7 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|376014|7416014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?L9TmdO+u4t2CJNJNRN3WfPkvRFhuWEcKvfXDKMWoGYlNsXYGwQ0yrII0Ivb1?= =?us-ascii?Q?7vkNZcmxguicuG80Y4vcuoZV8jMqdHPd2gGZUuNaZVxwjNzMP3Zn7UQe65GD?= =?us-ascii?Q?qKI8S42EIhmra2BbNic44NbL/+CjCezgNX6Sb76fGQ8IYS3JEiJIHTSYBtOE?= =?us-ascii?Q?QrUpvj9qKHtZ8Amt1CMERj3tTN9YSUHmlmUuuIcxWQBX1bI+YKZQkvJPDoc7?= =?us-ascii?Q?Q3w5WVvlLWEjJ7Q6Ex5Vzp/yFFl5gLoaTtAc6H/bIoCXAnmyyCphHvHsWAzk?= =?us-ascii?Q?GQBbhYitdRkdhtNMwB/hewWemksU665fq6kff4cJN625jcTjnbuBxwRE3Zsh?= =?us-ascii?Q?P8uTMIRtHaEhWU2NB2ZfMfP7KZjHVH7efAVb2lPzDxb3UFOuOSkwOl+MwbRE?= =?us-ascii?Q?xKD4AsgkbvWUiowiPylkanDRSHAhjH3jgkOXQ21NVclfVNXxNJNUtC9mABCA?= =?us-ascii?Q?6uvOBmFhor+Hcr7ojstqpqDL2JaRJRM6OD0bjyHns9Dd1s8PauKX44N/2I+4?= =?us-ascii?Q?FU/rjxjGpEdy4hh9wr0ychrXroBt+Nc/eARCZE1NbLQ25bZvN9WVY6azlkm8?= =?us-ascii?Q?vltE27IXOktv5RSpDoHEB8HRH+lxVC6RFOcIpF0koIwlTV3iSwCM7NBpsE4h?= =?us-ascii?Q?3Y4dSjXaq9C/bkiZjeyMpHyxoYtyhYvcL6W418HOSP9H2jmKa3ll3vbksxJv?= =?us-ascii?Q?I3zRjbEJNa2US+VHCYvo3fa/2iypxHfCFZdF41yD/GuHGLjoyZdBX76DGWYp?= =?us-ascii?Q?MbNy4DlVuwLjXiIb1m9nbBzyICeyBQRu1xN3Ia4+S5XiUFZQ135W0kpr0qVR?= =?us-ascii?Q?jWm1ZUJYTQrpB+yVcjjqqooKFOQiJb5UZ51mwsWsM3EO8OU6iWsTVpmEERMV?= =?us-ascii?Q?DGvTSTFxN+esRFD1IZSU0TczHybBK4F8QH0igFslLMhH2It6bpzm5pKsQntJ?= =?us-ascii?Q?kFOIE3UpfAkfgG245DNjsf7eVtkSadLB5dIhkc6QlxOpFjKSbmnP5OFi5GjG?= =?us-ascii?Q?iE2zGCFSRAXUR0yL+DmpesD+geRjiDQNlLB/bMTFqHmWCwt8aLfsjRyZvLKo?= =?us-ascii?Q?prUmDLweIiWZy2iwfi7sK3BNtc5A6akf57Lg8lphYylzZVqFokEazA+wsVnp?= =?us-ascii?Q?rg1uHQNg3gw6txmjjwN6QnOb6UiB/uQSoRgSQtQ+QbkTyObeQUacWqZfOV+D?= =?us-ascii?Q?JqvYfpiYZh+AmbIQuQc/C8K2188yTmUkxI2nqf9FnRLm7IQqrhR343RXBHhU?= =?us-ascii?Q?iHyB0xMVdyZaiIHgndTfJmDXQZDjeQRm1/+A/NJ+8qe8yZFXoYwnZ15svm6M?= =?us-ascii?Q?IsGiAqyUVnZqvb+ylCWsLVr7WyNrm6+PH0z74CY6B1MHWLwblvJnRA3HmEhO?= =?us-ascii?Q?scQT34Gbuyv2i/v9hOjuVsJXC+rO?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CH3PR12MB8659.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(376014)(7416014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?Y5aYtQNR25+algwOZDneW0kScR0/grlP0bNHyJGC4J2M4Yy6vwFAkdCK7OYT?= =?us-ascii?Q?iqA8P/qY+Fn/YdRU8TTvuSBhtHP4UQPrY8c+SqypSjbi50XQnMvXDMII9eSE?= =?us-ascii?Q?H9DWiRloIfKpTQpO6QgjefZwc86F82j9LhHDeIjoAemQ4vuOvVc2bIUHQqfW?= =?us-ascii?Q?HLb5bpVKkLAE2kPvRPQx2Wj0c6pVQkDDD1rdk+DEO++oDrl4TBz+03WKY3qO?= =?us-ascii?Q?SS73XkKm149dYyDV2VU7Qzyh0F8NH7acwhNew03JN+6oGHTCJ5PwIVo5Ok+/?= =?us-ascii?Q?8g8BEyY6hz7WPWZ7MJn5qulSLIl+JhDwR7hWv2hDXmk4cn8uZle9XDkvWh6X?= =?us-ascii?Q?tp7XzQA0Jy+qKmFN+kr/sSV4g3A3PEsuGortaHbue/GYdf+ZOiyqCnyD6ExZ?= =?us-ascii?Q?35UgFa5AyjEPWzQuABNZBHw3O0trA4ZbHWq/VFUIRdpSV29WOwf2gclnSQfr?= =?us-ascii?Q?A9yqICaQpxqQXx1cseFK7W4dIUqkKmtKCTdIFVvdpgDFj/hGRbVCxvJXAHaJ?= =?us-ascii?Q?goZm+d8LlvknFKC56rA1FrkuAVxVc4VkUY6yqgY3CT2sLiUDzrDUatb/QVVe?= =?us-ascii?Q?iWdFGHuoKK6Wx/X+ExA2+5Y4dATuEStK7xz2dsR9ydaJ/vpPWGYazoMFrDcB?= =?us-ascii?Q?BN/g00hQdiss4HFB7lJzpvrBBd0b1lCegEK63KXiMh8gRR96Ev/MF98HmaLE?= =?us-ascii?Q?wFPj16gaffMYOgjMfKxtXO8wdt9ZYDAXNftogN3ecXOG8he58YjYNDGspT9E?= =?us-ascii?Q?BVaYcGHE+rGf4Bbc734JU+aBmzmfQc0MBtUFYcSZViVO1nmrE4xWq1PD68x8?= =?us-ascii?Q?+RfymkrGoo2k3vocNjq6Re5FmGKhKXH/1YT8/Ymt0xJ6VI9Fn4366/rgSY8S?= =?us-ascii?Q?ZQgVP9K0YiA0gguyeg9xjGkkIqPPuKs5Ll7T9cKLvqv8gmBQzepDOKgbiHg6?= =?us-ascii?Q?+hgDNE9yQyQeQcs3O1MF+Em1Lgdr7UjdxHaqBms1dtfEVOMH805ryEBtYuFp?= =?us-ascii?Q?Bi9dTqaqgsI6K8aIWoPGqi/TNGva+dppBtY0PoqQk1x6gOxGpv3OHms5uIr2?= =?us-ascii?Q?zy277c4UzzVpF8IjRV6FELbaA5XlQWX47elojgUuD8Fzbksb422lGpFT4dgy?= =?us-ascii?Q?OHgHMlvPPikTbmYEzlO2GFD0d8s5LWIntNQKpbtWFzIR8bqwFM29G8FYw8kt?= =?us-ascii?Q?4u4bhgmJInd2jruP+lWcuO0JdQcqJq+rlSux2pv2RneBbFcDX2loj1kUY4rq?= =?us-ascii?Q?aY97jTcEhC9cQ8zzXaRTIIJEJDfPA+kYgZG463SWkS+iyQBaMkelubxnHs//?= =?us-ascii?Q?eBnurNQRogTOoFgwMhon/DU0XYyuxetXdV1PfRjt2RXCD8MkmcAGy6kmrL3+?= =?us-ascii?Q?ZiiN7sUe1q35u/eeN1eXOLbhuvhHMhNGI70gR23fF196e/q/iJmtC5Qrx3g0?= =?us-ascii?Q?sSESIJF4GcHohSIC+hsyEugCdLf3Pqa82l6XYTlUS+145KX9USJUiQF9/nc/?= =?us-ascii?Q?YasQqKVnuCzeeOp14nW5E4VkyYTuRJXm3rEq9+7yuFMPmaXHDXZJ7sTrTXQN?= =?us-ascii?Q?pqw2k8/BR78mLmAsyaZGse59IQkXr+JQEeDT5igD?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 2211a832-49a5-4542-84e9-08dd75dfc2c7 X-MS-Exchange-CrossTenant-AuthSource: CH3PR12MB8659.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Apr 2025 14:23:26.4596 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: Bk6hQfpUpya+DMbNcKh1mHZbOj5KBBQCVz/bz9lrlRlZMHfLSXQrvZJf0D9z+Bpv X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW4PR12MB7167 X-Stat-Signature: nzkpaz4x4kdz71nxq66dd14pon881nm8 X-Rspam-User: X-Rspamd-Queue-Id: 54F5380002 X-Rspamd-Server: rspam08 X-HE-Tag: 1744035810-411602 X-HE-Meta: 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 N4bfEd1O 0Ojiu5IMobMEWwFgLzXz5Mwp/WsI9dr/H9T8rgLMpYV36YaAY2lbuwzK07bYssA7bpVHJiOsnpNKbpYqkQ59PhGqh3jSZpUCh8S407DXDxbc3tYH6HCFVlCNQTuHUxaWt2EhMo5NZru+pbiEbZktjAPJ+OrX3pj6nd9LMU0RIj8DuU96AQJGkSxQaYRitXVbc4j3mX4ld/h2lKegjSuqLzZn1vf53n7WDr80g2kNH9R9wcbrbfYF6X7+KP8tkQE6HFDLjVBiYqVMEryJ2ADjfkqAKqtk4xSCd4lua0vm/ZzrUVA57G+RPL/yAROCsTOx0uTgRcFpIpAFTdrgCW8gHRnBeu/BlnMYD+s0H8ukV8wRsNhAfKRU60ReL5XcN2vdEqhAyspJJxB7qWofI0f5opO2zL1pSMCHNPAqd0WJ8Vc6LFQXGu0wqXP+PwEcUvswsbzlQCImU+HB/gC2/FK1Pthsz6UIJTWUzJNo6 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000031, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sun, Apr 06, 2025 at 07:34:30PM +0300, Mike Rapoport wrote: > It's more than 200 line longer than maple tree if we count the lines. > My point is both table and xarrays are trying to optimize for an unknown > goal. Not unknown, the point of the bitmap scheme is to be memory deterministic. You can measure your workload and you can say I need XX MB of memory to succeed a KHO using bitmaps. With maple tree you need to both measure your work load, compute a worst case fragmentation, then say you need YY MB of memory to succeed the KHO. Since we are looking only at worst case YY > XX These are engineered systems, there is limited memory available to the hypervisor, and every MB is basically accounted for to minimize the memory requirement. So every action needs to be worst cased and accounted for in the hypervisor memory budget. > As I said, this means an alternative implementation of the memory map and > free lists, which has been and remains quite fragile. > So we'd better start with something that does not require that in the > roadmap. I think the obvious next step is to use the bitmaps to generate contiguous ranges to pass into memblock reserve. That will get you performance equivilent to mapletree and deterministic memory usage. Jason