From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from BL0PR03CU003.outbound.protection.outlook.com (mail-eastusazon11012049.outbound.protection.outlook.com [52.101.53.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5BB403DDAF5 for ; Tue, 6 Oct 2026 08:12:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.53.49 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791274375; cv=fail; b=ksNoI80BvvNFZ6ysXQoNKqRqBCj9hWEdh7XkrrJP5p1tlJT1mpIqVvmJIEGumH78FBs2Lkc/csZEsrSM6CeFYnbu57LbHy181ikcGte9w720fse0Q8vm58qnQT2icC9n27oW7YljaVZ/xv25ARVShuXvt1CZzR3Kp9aG+qrUNPM= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791274375; c=relaxed/simple; bh=Zms3rf8SczcxPSkqpzPcHQPYS9862avARhbRn27hpM4=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=rZcVCOzUOqnEHnA499XyroRYS8MnIFBkyelpPY5/IfJLXDq308tEm7e34wU7+dXWfS6zRh5jd4IbtG0YOWMopfHGNgY9wGOVDzSNXVSp4CmFWm+DnNoFWrwjL9bc2YDX3P68GtDkezHbHZ8wvyz3HFjb3H+Jq9obxoFJamedFfo= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=pQOx4QwI; arc=fail smtp.client-ip=52.101.53.49 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="pQOx4QwI" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=re3p7cjh5Mpa0gkDb6RE+8i0mnZsRsrFHiro3WrOuK7tdYW+nv/t14YqCAg4kJuD7/WuaSEm7vTOPVVh4qJniIxSFh+7nm7wXA5DtoLJdgjjevMxSPkzaAhqybwni7eBfXaaBRsGVkK2xvcyZF6kcmsZMY8D3o2w9640fDObUy0WcYKjm/foDwMVFF1tcj+oldbMxlqfIdxFexMHA+MMjfq6qcJcnEihFIrQsC8XaG10ARZXa8g7GDgDvv8Fp3Y1HwMpMx2di+haDfLFRc4mEFlEgIZ8y0uwEuIXh2EjIXE8i97GzQLlOl8MVVwnPU62rhQXZm0GRhH6NvZ4rhdLCQ== 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=gH+S8yij+1mG8LgbTZ9S/pql6SOCBFXIrjFMp1hAQb0=; b=jJCfEXpdawUOl1awxYvru8X4marXr2L7AixvCrq5UYfYVx0XilUv6k9Y8mcz/YNga3uNjdgliq2HWrQI1/Yr+U0r4F4r03AyaSzZZLfMCgNsco4DvEB9LrxNzmoUUWXd7sNtjj9xuz/BxShcZ3CCHctgGToGd42GHdcN4mlVeykLMpZfhMrha+/ec54qDcJWed+7KOeJv9xkYpn6IarW7lq0CbUjwepDKCoOt6VUvQ7RgV0WrvgcvqMcZnbd/PheVrOfAn1YG02dJnV8mwH5aHAuq+GRds0Kue3txsy9iNi0nI+LCkZBZYzvckWj5bN8Lzh/Yd0Gl10Nwh3/y5womA== 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=gH+S8yij+1mG8LgbTZ9S/pql6SOCBFXIrjFMp1hAQb0=; b=pQOx4QwI/eLQ7dEEViGUUKUUg0xmNgltywKIJDkVf0s3agIO95LBju7vTZpS+PK4k8ICwxb4R6O9F78vtvvhj+ESO+VzWAtxkADCLPcLuvm3iKm7VHqkUvxpY1L3Z+7vPc8C49MkHbjTKpsBc7/k/XpBP2c09pdZHP55Eg776lQZKrJbfcy30J29GkG3JQS3YqGGm//mU4ntC2jHH5vFkDQPguKqCXvOd+59co0skTfzDMZ2RYJEOcpuYaWw6eyIXmXL0aQbEKHtpeCbPU0ke0eZAqwjvdI0jemgNQRPh1/K/hIXcSOFgcULCgmBt58hTvPe2jkcls1DqAdqAtQGaQ== Authentication-Results: mx.microsoft.com 1; dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from PH0PR12MB7957.namprd12.prod.outlook.com (2603:10b6:510:281::22) by DS4PR12MB9681.namprd12.prod.outlook.com (2603:10b6:8:281::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.472.20; Tue, 6 Oct 2026 08:12:46 +0000 Received: from PH0PR12MB7957.namprd12.prod.outlook.com ([fe80::9251:acc2:cc63:3499]) by PH0PR12MB7957.namprd12.prod.outlook.com ([fe80::9251:acc2:cc63:3499%3]) with mapi id 15.21.0451.026; Tue, 6 Oct 2026 08:12:46 +0000 Date: Tue, 6 Oct 2026 11:12:37 +0300 From: Ido Schimmel To: Kuniyuki Iwashima Cc: David Ahern , Andrew Lunn , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Chris J Arges , Kuniyuki Iwashima , netdev@vger.kernel.org Subject: Re: [PATCH v3 net-next 0/6] ip: Batch flushing uncached routes per batched device unregistration. Message-ID: <20261006081237.GA582799@shredder> References: <20261001204752.2572265-1-kuniyu@google.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261001204752.2572265-1-kuniyu@google.com> X-ClientProxiedBy: TLZP290CA0010.ISRP290.PROD.OUTLOOK.COM (2603:1096:950:9::9) To PH0PR12MB7957.namprd12.prod.outlook.com (2603:10b6:510:281::22) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH0PR12MB7957:EE_|DS4PR12MB9681:EE_ X-MS-Office365-Filtering-Correlation-Id: 61fe9554-5557-4c3a-2596-08df23819a61 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|7416014|376014|23010399003|56012099006|5023799004|11063799006|10067099003|22082099003|18002099003|6133799003; X-Microsoft-Antispam-Message-Info: 3usVpjCaXk8HiFnLhRjgurmIqTCvnjfK+mlA5J1Lc+fIltjmDs9XL3eZGLvM7G6sgSOxoyr6vbGy9QpwtCorH1zcZcDvfAlHhEC0IItxrp90gdTZJZbin92icxrurb4cNKYf6V+ogpVRvlUDt5lDaI49iVg/T8JMA4lGKDq1VrM8a966rFEbEeJppnMQvGAcGcMOxS32Khcf7ekWLJpgbSeZzB4o6WISUzs3QhzZcB+zlVETfNmTR1YWQy4M9BmArojO64vZ6O4xyGdpnd7HOGJgL8SBT391PbJdzohwG+ObTym63fUCXv2zCBlTIUbNUUkWz+dq60r5QlmYNqZ3Fpo7Ba0yq/6laBCQhcq1U9801TE8+2/U5LmQcDCwf9ZsmvFKvBgBy1fxvr4UznONXrWonV8dp/+Dn0VIsm8sJyhjwZymIRrTsRsVSsyFUAlaB9q48q1/pqGai+M6cTzuEep5F5gKkLzIqjE2F381A0WKgL5fFpMZk8OaRq5L7d1hKKdM07F7m1S3l/HBcR8S+656468DGBlIMgtJWuLoRm+6keK6gKFag5+sXywtffFZmRoPcW8BoR7m4s3sQORzSHFJ/X4kxHNXcNb6EUPyWe9cY4lItbp6hbzks9swbUWYNOIFjIAq8DLS5GzI6va0oI+FO75rWJdi/mmjmu8VfAU= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH0PR12MB7957.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(7416014)(376014)(23010399003)(56012099006)(5023799004)(11063799006)(10067099003)(22082099003)(18002099003)(6133799003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?uWBTYoJ31yYT3q7hsvtxdMqeRqXhvW5upUuIofyKF9Xg+4TvgB+m6iroiksj?= =?us-ascii?Q?kz9/OwuYCCC80irv/MPKAV1UYXMMkia2vi0KuPTQO6DfoOcoIHOZDBLhG+Xy?= =?us-ascii?Q?2B5iWiFf8QAb0NJV/INuA7zCsAGhf6E+psFlVNW6SK7eYTCnoIadD5Ll1KXb?= =?us-ascii?Q?lyis2ImzMSAAwTWHn7J/x9wFl8jR1QoE70LgLEqq1W441ntQWlBrgjECyjgN?= =?us-ascii?Q?FOX34GLNGTICMkrjRIYjPBMDlqLiIG/Qb4W1Tma2dgnd97k6PZL6COt/yIfm?= =?us-ascii?Q?mBWzSdYnCpj6hyYBoNTtxXVJP5sUDzUA2OAaGhhIe9dUU4dcQ5S9SgUnXgLQ?= =?us-ascii?Q?juVlOlsdW+0LYmE2iHAuqLlXBxVzBQCWnkLQfOTJc6TU46Dv3gYGyWJ737Q/?= =?us-ascii?Q?tVfGKTuoSTMBDbwb0OmqAuoAVsP3/Byqav9xsNi4g9UxC54N8sgKSIcQxAiw?= =?us-ascii?Q?vjVWKHNbp2AmCgL9w4ivJC931XNZj3f+nc6yf5jcYC0Q3sGGrE9vZNBhwIr6?= =?us-ascii?Q?fVJlj580GlyUrZahPkudc8dPnDKUcQ41rbtQCsokpBIk+6V4pVgpQ9MwF40g?= =?us-ascii?Q?ABdVD+15tJJ7vRkY6URy3GKNOJDUd5ymBJTqsyf3DeZidx8cw+OFWJRN8paA?= =?us-ascii?Q?BY0Yrsc6OFCsdyUnQ/QyXjK3ey+joHkg1vBpA8Ih2zc8HV++RTD/u5LuKUfV?= =?us-ascii?Q?U7WiLf4MAd+XWxF5T2Fz46fcGTuM6DxnkYSj42FBSnXfRwjg2A18/A42ZAZ4?= =?us-ascii?Q?brDMTFAeKqd6JaoiWTvC20V1C7jmdYZ2w8ud5m3+bJkK22nuYxtpBvgFWm4k?= =?us-ascii?Q?Kmq4WAvBED72l5CXJcNRzFFFe8ftXxSNe/m8AAmaAF5PhFOymU4dK3VSP6oD?= =?us-ascii?Q?kLQ6At3BXUzwQcY6Ci6nFz+h4ipdL17Ve7cExPu83w5TxpkWQTxZo12NYt2s?= =?us-ascii?Q?z+WxCZcQnL0P2hVPJiL7RGZ3f0Bj6EOjorAtN+FcmkUAo/GVE5iM9nHIM5mj?= =?us-ascii?Q?F7QBTaqfYO3N3fR1aYMW+Xh2r1ofDquZf649f4wnApjkd9oBC6IsKBsrWmyv?= =?us-ascii?Q?2rVsW2Mt3ofbPO71JWIKRpg2gzF5XXLT0tI4bs1jM+rf/MbFzfIW+ByPqgAN?= =?us-ascii?Q?bkwi3s+CgHVcGj8l2N7W+XmI6Qt2kO0mfpkTUSsfSwT6PQEwH+GMS7uQQxQt?= =?us-ascii?Q?IgDPyRTsL4yOk5A3iIzHE+L9vTgGgl+VpYpoGj7lRFfHKoH0KMKianLRb9Do?= =?us-ascii?Q?B9r7DCW7TOgGwpou4gfCLadTD4BnT4e1ppmd4idVMoOlcYEvwjzHxWd6DfWD?= =?us-ascii?Q?tEniD3MyoSmMFChdPfgQJw+KMKyHzK2WV9e+fFiKjGbZGDtzECbWWRHZUXZZ?= =?us-ascii?Q?RZeR8Zul3ArCCAyOaw7sVPtL2cus7IwdiZ2GgesxjsPeb7RJPwrtQwaCFYPL?= =?us-ascii?Q?32uTJ8JT7lSm47b6bEWtsyk1eluy1enYQ4RU1LtdbgX51JahPlSo1wSbUV2y?= =?us-ascii?Q?FZEg+l7GKSCF9EbrhdvmmT9BmNCjOXZgsHEL4hL0P0Zdm98r23yNB96B14Hl?= =?us-ascii?Q?7sNXb8xJJWzhIaXwnHEDR6GB3ZwvLxGNVu1WaXKUSiKfkzl1FMnRReGWxoaL?= =?us-ascii?Q?WVOPsMCjvPBNRabmq40yr0LzXC/iF6NV/daPtQZ+LSpS292eKHY4T3RR3Qzz?= =?us-ascii?Q?ExFQoGMdXZv4vgZgRVFJqyOmGeDU/MqGuz3v9PW7GAImmmxU?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 61fe9554-5557-4c3a-2596-08df23819a61 X-MS-Exchange-CrossTenant-AuthSource: PH0PR12MB7957.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Oct 2026 08:12:46.0879 (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: 1Ygnz5BM6te22Bny1FpEj2eboO46DZ54SviIN19F2SgwPeCzSt09SqyJ/qm2lsq+8TERcas8GEwcpSp/Q0gD0A== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS4PR12MB9681 On Thu, Oct 01, 2026 at 08:47:12PM +0000, Kuniyuki Iwashima wrote: > Chris J Arges reported high RTNL contention during cleanup_net() > caused by rt_flush_dev() and rt6_uncached_list_flush_dev() iterating > over the global per-cpu uncached route lists for every netdev in > dying netns [0]. > > This series resolves the issue by batching the uncached route > cleanup after __rtnl_unlock() in netdev_run_todo() > > [0]: https://lore.kernel.org/netdev/20260917-hash-bucket-route-lists-v3-0-30493a37b6eb@cloudflare.com/ > > > Changelog: > v3: > * Add patch 1 ~ 4 Reviewed-by: Ido Schimmel For next time: The cover letter should explain how the patches fit together. Otherwise it's up to the reviewer to figure it out. The dependency between patches 1 and 6 is not immediately clear. My understanding: Patch 1 is needed so that the IPv6 uncached lists are initialized before they can be traversed for devices that are unregistered due to failed initialization. Patch 2 is a cleanup that is made possible by patch 1. Patches 3-4 are preparations for patches 5-6 that are going to walk the uncached lists once per batch of unregistered devices. If a dst entry that points to an unregistered device is put on the list after the walk, nothing will clean it up after patches 5-6. Patches 5-6 avoid walking the uncached lists for every device being unregistered. Instead, walk the lists after one or more devices were unregistered and delete from the lists entries that point to such devices.