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{ "id": 125, "url": "http://patches.dpdk.org/api/covers/125/?format=api", "web_url": "http://patches.dpdk.org/project/dpdk/cover/20230908131737.1714750-1-artemyko@nvidia.com/", "project": { "id": 1, "url": "http://patches.dpdk.org/api/projects/1/?format=api", "name": "DPDK", "link_name": "dpdk", "list_id": "dev.dpdk.org", "list_email": "dev@dpdk.org", "web_url": "http://core.dpdk.org", "scm_url": "git://dpdk.org/dpdk", "webscm_url": "http://git.dpdk.org/dpdk", "list_archive_url": "https://inbox.dpdk.org/dev", "list_archive_url_format": "https://inbox.dpdk.org/dev/{}", "commit_url_format": "" }, "msgid": "<20230908131737.1714750-1-artemyko@nvidia.com>", "list_archive_url": "https://inbox.dpdk.org/dev/20230908131737.1714750-1-artemyko@nvidia.com", "date": "2023-09-08T13:17:34", "name": "[v4,0/2] fix memory initialization deadlock", "submitter": { "id": 3172, "url": "http://patches.dpdk.org/api/people/3172/?format=api", "name": "Artemy Kovalyov", "email": "artemyko@nvidia.com" }, "mbox": "http://patches.dpdk.org/project/dpdk/cover/20230908131737.1714750-1-artemyko@nvidia.com/mbox/", "series": [ { "id": 29463, "url": "http://patches.dpdk.org/api/series/29463/?format=api", "web_url": "http://patches.dpdk.org/project/dpdk/list/?series=29463", "date": "2023-09-08T13:17:34", "name": "fix memory initialization deadlock", "version": 4, "mbox": "http://patches.dpdk.org/series/29463/mbox/" } ], "comments": "http://patches.dpdk.org/api/covers/125/comments/", "headers": { "Return-Path": "<dev-bounces@dpdk.org>", "X-Original-To": "patchwork@inbox.dpdk.org", "Delivered-To": "patchwork@inbox.dpdk.org", "Received": [ "from mails.dpdk.org (mails.dpdk.org [217.70.189.124])\n\tby inbox.dpdk.org (Postfix) with ESMTP id 1BF8542548;\n\tFri, 8 Sep 2023 15:17:49 +0200 (CEST)", "from mails.dpdk.org (localhost [127.0.0.1])\n\tby mails.dpdk.org (Postfix) with ESMTP id B9889402AF;\n\tFri, 8 Sep 2023 15:17:48 +0200 (CEST)", "from NAM11-CO1-obe.outbound.protection.outlook.com\n (mail-co1nam11on2059.outbound.protection.outlook.com [40.107.220.59])\n by mails.dpdk.org (Postfix) with ESMTP id EC06440285\n for <dev@dpdk.org>; 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helo=mail.nvidia.com; pr=C", "From": "Artemy Kovalyov <artemyko@nvidia.com>", "To": "<dev@dpdk.org>", "CC": "Thomas Monjalon <thomas@monjalon.net>, Ophir Munk <ophirmu@nvidia.com>", "Subject": "[PATCH v4 0/2] fix memory initialization deadlock", "Date": "Fri, 8 Sep 2023 16:17:34 +0300", "Message-ID": "<20230908131737.1714750-1-artemyko@nvidia.com>", "X-Mailer": "git-send-email 2.25.1", "In-Reply-To": "<20230830103303.2428995-1-artemyko@nvidia.com>", "References": "<20230830103303.2428995-1-artemyko@nvidia.com>", "MIME-Version": "1.0", "Content-Transfer-Encoding": "8bit", "Content-Type": "text/plain", "X-NV-OnPremToCloud": "ExternallySecured", "X-EOPAttributedMessage": "0", "X-MS-PublicTrafficType": "Email", "X-MS-TrafficTypeDiagnostic": "CY4PEPF0000EE38:EE_|DM6PR12MB4044:EE_", "X-MS-Office365-Filtering-Correlation-Id": "71210f49-9c4d-4e12-40e5-08dbb06dfd13", "X-LD-Processed": "43083d15-7273-40c1-b7db-39efd9ccc17a,ExtAddr", "X-MS-Exchange-SenderADCheck": "1", "X-MS-Exchange-AntiSpam-Relay": "0", "X-Microsoft-Antispam": "BCL:0;", "X-Microsoft-Antispam-Message-Info": "\n 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", "X-Forefront-Antispam-Report": "CIP:216.228.118.233; CTRY:US; LANG:en; SCL:1;\n SRV:;\n IPV:NLI; SFV:NSPM; H:mail.nvidia.com; PTR:dc7edge2.nvidia.com; CAT:NONE;\n SFS:(13230031)(4636009)(346002)(39860400002)(396003)(376002)(136003)(1800799009)(451199024)(186009)(82310400011)(40470700004)(36840700001)(46966006)(8676002)(5660300002)(8936002)(70586007)(4326008)(40480700001)(41300700001)(54906003)(70206006)(316002)(6916009)(2906002)(40460700003)(36860700001)(47076005)(82740400003)(83380400001)(55016003)(2616005)(1076003)(26005)(6286002)(107886003)(426003)(336012)(86362001)(356005)(7636003)(478600001)(36756003)(7696005)(6666004);\n DIR:OUT; SFP:1101;", "X-OriginatorOrg": "Nvidia.com", "X-MS-Exchange-CrossTenant-OriginalArrivalTime": "08 Sep 2023 13:17:44.5940 (UTC)", "X-MS-Exchange-CrossTenant-Network-Message-Id": "\n 71210f49-9c4d-4e12-40e5-08dbb06dfd13", "X-MS-Exchange-CrossTenant-Id": "43083d15-7273-40c1-b7db-39efd9ccc17a", "X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp": "\n TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a; Ip=[216.228.118.233];\n Helo=[mail.nvidia.com]", "X-MS-Exchange-CrossTenant-AuthSource": "\n CY4PEPF0000EE38.namprd03.prod.outlook.com", "X-MS-Exchange-CrossTenant-AuthAs": "Anonymous", "X-MS-Exchange-CrossTenant-FromEntityHeader": "HybridOnPrem", "X-MS-Exchange-Transport-CrossTenantHeadersStamped": "DM6PR12MB4044", "X-BeenThere": "dev@dpdk.org", "X-Mailman-Version": "2.1.29", "Precedence": "list", "List-Id": "DPDK patches and discussions <dev.dpdk.org>", "List-Unsubscribe": "<https://mails.dpdk.org/options/dev>,\n <mailto:dev-request@dpdk.org?subject=unsubscribe>", "List-Archive": "<http://mails.dpdk.org/archives/dev/>", "List-Post": "<mailto:dev@dpdk.org>", "List-Help": "<mailto:dev-request@dpdk.org?subject=help>", "List-Subscribe": "<https://mails.dpdk.org/listinfo/dev>,\n <mailto:dev-request@dpdk.org?subject=subscribe>", "Errors-To": "dev-bounces@dpdk.org" }, "content": "The issue arose due to the change in the DPDK read-write lock\nimplementation. That change added a new flag, RTE_RWLOCK_WAIT, designed\nto prevent new read locks while a write lock is in the queue. However,\nthis change has led to a scenario where a recursive read lock, where a\nlock is acquired twice by the same execution thread, can initiate a\nsequence of events resulting in a deadlock:\n\nProcess 1 takes the first read lock.\nProcess 2 attempts to take a write lock, triggering RTE_RWLOCK_WAIT due\nto the presence of a read lock. This makes process 2 enter a wait loop\nuntil the read lock is released.\nProcess 1 tries to take a second read lock. However, since a write lock\nis waiting (due to RTE_RWLOCK_WAIT), it also enters a wait loop until\nthe write lock is acquired and then released.\n\nBoth processes end up in a blocked state, unable to proceed, resulting\nin a deadlock scenario.\n\nFollowing these changes, the RW-lock no longer supports\nrecursion, implying that a single thread shouldn't obtain a read lock if\nit already possesses one. The problem arises during initialization: the\nrte_eal_init() function acquires the memory_hotplug_lock, and later on,\nthere are sequences of calls leading to rte_memseg_list_walk() which acquires\nit again without releasing it. This scenario introduces the risk of a\npotential deadlock when concurrent write locks are applied to the same\nmemory_hotplug_lock. To address this we resolved the issue by replacing\nrte_memseg_list_walk() with rte_memseg_list_walk_thread_unsafe().\n\nImplementing a lock annotation for rte_memseg_list_walk() to\nproactively identify bugs similar to this one during compile time.\n\nArtemy Kovalyov (2):\n eal: fix memory initialization deadlock\n eal: annotate rte_memseg_list_walk()\n\n lib/eal/common/eal_common_dynmem.c | 5 ++++-\n lib/eal/common/eal_memalloc.h | 3 ++-\n lib/eal/common/eal_private.h | 3 ++-\n lib/eal/include/generic/rte_rwlock.h | 4 ++++\n lib/eal/include/rte_lock_annotations.h | 5 +++++\n lib/eal/include/rte_memory.h | 4 +++-\n lib/eal/linux/eal_memalloc.c | 7 +++++--\n 7 files changed, 25 insertions(+), 6 deletions(-)" }