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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , David Ahern , Simon Horman , Kuniyuki Iwashima , netdev@vger.kernel.org Subject: Re: [PATCH v6 net-next 00/15] neighbour: Namespacify arp_tbl and nd_tbl. 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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?NLYWiJmdZeXHNP33Ca2kaEzJyophigVGoH/zY0GCKWsHP/Anyq8+1A3462Hh?= =?us-ascii?Q?ds4qlj0pFYMbpeu2XjtKC/oDl7FDCDK63GAA5jk1Guh5L69Uo0Z1fhdKi2AA?= =?us-ascii?Q?v0Er3CWP3GpSGnLM6KpojYqZktdy0mIkuDXaqvnlB3m5RCiOCe/Mt7Jn6VOL?= =?us-ascii?Q?X5dmgjn+zLDEZ4u/x2W/C/5E5zCq70W8RjpRd6B4rkgduE7Y+i1rq/yn6kB0?= =?us-ascii?Q?zj6wwENihhM/n1OwTmnvOdZ11Z9n7JvgaVe7aHiughCg3aRMt5ViG7zgWlha?= =?us-ascii?Q?yR8UIXH/pNLJB4vovQaG6r229G3T36FYCOuA4SqAqoLGWkr81BRf9SpbOWbG?= =?us-ascii?Q?HfzxV1PflYmXrQYKu2qDFaICCfHeN06m8Q2jHbXMWDPzIGUctUf8Af7KWWMV?= =?us-ascii?Q?lZ+HXNYDoxyP0LvTMIeIJsEkbM/n9RkcgI+1a4HItnsQ2AEiONYdwYtjj1pa?= =?us-ascii?Q?vWx8650SkKsdt9DCiPv5j5Cr7ElF/6LBkJsqgiGJURt95nW7REMKfTj1NkCu?= =?us-ascii?Q?iucbjMsgD2W0e+6yvDgkQPc56KxBTa3lYA0erwQdxJIYtz6KRXvBq0P1+aBq?= =?us-ascii?Q?+KA/Fy+r++65lYqUF2bjTk1jG35sy5+pKoHIpSF7R8a1fkKT6iqAoIH423iE?= =?us-ascii?Q?Mwi+k9HtcvHpaBSltp9IHcoJ7MHDdN63yXGKM0mdpTVw2+qdYm6aA+tI21GV?= =?us-ascii?Q?90bNjDu7P0P/L1DmtdvKDkpP7QCfyxRjuzIoE48GFLVeFizcBGjx7nseb5lG?= =?us-ascii?Q?IiR0MAJqHuM2nS2M9DsmYTmzAGIuB/jYrNiPlIk5tofFHLet12btDReN9Aws?= =?us-ascii?Q?lezRJKQAX7YmNIgkJX8b0bcFguQbA/SVtzlXRrvXf+OkfrjmCo/lJzGdU6EW?= =?us-ascii?Q?fcqJr2f3XGwza37O0jKQBTE2KUZslYOiFKGGvq6KGYleVGFV2agznwdSBQxE?= =?us-ascii?Q?gALdqSY4NAMP/MtQxLU7kDLUxrlXfvwrutaH2lRuEXEmYpseZeHfZrs9DaGV?= =?us-ascii?Q?w64fPwts9WoQY/AMh83VgjBxSXHfyjiKVde1A//1qUocyOREb1zdYVhtsl/E?= =?us-ascii?Q?eViGK888HzR2CaFqFJC8TQGV4aYCykucOoxLCkr16MjrA+RF7k2qksT1kUY2?= =?us-ascii?Q?wKyO34uVdz3PZwM8Q1lBtzSy/06L7REgbBIUkF/FqaTC6YpSk6ahBKA/Aj7p?= =?us-ascii?Q?EfoNUAHdV6dYVARUb1QHekAWos6xvM23wVhztn0Cg8r8OYJDZrv8IVHiGJBX?= =?us-ascii?Q?u1uEdH4Cymgd2OXfbQRRGkOYj5V3KcVULzhodTEVCy8+u7FxmdOfaT0IImEK?= =?us-ascii?Q?0ThyRgOszIlzWUa49OkUqLjv0AWwQLmje+vLpWkUpf34x2LyIMgkz6vv/Z/o?= =?us-ascii?Q?cK+5sHmvNLyVVtrTsfy9AwBD56fhiAjWoKkN1kemRjBIvuaO2TkACEAwwXCo?= =?us-ascii?Q?PdqxtNBoVQcJ3QabncFSD4FehicVIdTy+8L5U5ZvctgzQOtnBh4v6Xx5ga/G?= =?us-ascii?Q?v0cGqbszEjOKDszoIB2z3vcacdnTPZws2NxjgfBNcsQmCr0nOGg2ujSWlL1T?= =?us-ascii?Q?snaWqkANwhv6WZmTnS+J5V8B3ht91bhAFATiOP+DLdokHAzJyz+JlF5auMP1?= =?us-ascii?Q?XMkoDHT3+kNq1rqMj93y3JdgNutdY3RrUAQCmMoMphB9sUNltfKep50hjRL+?= =?us-ascii?Q?SABYdjnb1Qa5F94oGF6nNcsuesWmKvLPBQiK8olYBdaYb4kT?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 4d3c1c74-d1d4-4202-0d15-08df09b9741a X-MS-Exchange-CrossTenant-AuthSource: PH0PR12MB7957.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Sep 2026 12:47:03.2692 (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: DM4PoFrKxPrtq8Nu1ycNnoKk5HCV/CAZS8r0KzEjDFUX+1QvezkD5DJhIL6lhy+QAnxDZc08L3Glep0cQ2SBnw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS0PR12MB8270 On Wed, Sep 02, 2026 at 08:36:41PM +0000, Kuniyuki Iwashima wrote: > The neighbour subsystem is almost ready to drop RTNL. > > However, the control paths are serialised by the global > per-table lock. > > This series converts arp_tbl and nd_tbl to per-netns table. > > With the series, /proc/sys/net/ipv{4,6}/neigh/default/ can > be configured per netns, which was only configurable in > init_net. > > To avoid potential regression, all the settings are inherited > from init_net by default, and this behaviour is controlled by > a new sysctl knob, net.core.neigh_inherit_init_net: > > # sysctl net.core.neigh_inherit_init_net > net.core.neigh_inherit_init_net = 1 > # sysctl net.ipv4.neigh.default.gc_thresh1 > net.ipv4.neigh.default.gc_thresh1 = 128 > # sysctl net.ipv4.neigh.default.gc_thresh1=129 > net.ipv4.neigh.default.gc_thresh1 = 129 > # unshare -n sysctl net.ipv4.neigh.default.gc_thresh1 > net.ipv4.neigh.default.gc_thresh1 = 129 > > If it is turned off, all settings are reset in the new netns: > > # sysctl net.core.neigh_inherit_init_net=0 > net.core.neigh_inherit_init_net = 0 > # unshare -n sysctl net.ipv4.neigh.default.gc_thresh1 > net.ipv4.neigh.default.gc_thresh1 = 128 > > Series overview: > > Patch 1 deflakes test_neigh.sh. > > Patch 2 ~ 3 are misc cleanup. > > Patch 4 ~ 7 store arp_tbl/nd_tbl to net->neigh_tables[] and > remove the global neigh_tables[]. > > Patch 8 ~ 9 replace the direct access to arp_tbl/nd_tbl to > net->neigh_tables[] using new helpers. > > Patch 10 ~ 12 finally replace the global table with per-netns > table. > > Patch 13 ~ 14 clean up unnecessary net_eq(). > > Patch 15 updates test_neigh.sh. > > Note that some buggy drivers access nd_tbl without checking > disable_ipv6_mod, so nd_tbl's extern definition is still left. > > After this series, I will follow up on two suggestions by Ido: > https://lore.kernel.org/netdev/20260902143023.GA3966681@shredder/ Reviewed-by: Ido Schimmel Thanks!