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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , David Ahern , Simon Horman , Kuniyuki Iwashima , netdev@vger.kernel.org Subject: Re: [PATCH v5 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?VcLIlrv3QUKHylLnJ7Pbs2DaKe5EFnArcV75mMBBnEThictzw1Ia7JCMKaYr?= =?us-ascii?Q?Aw0nNXfDqXVWJrnBkeIYGifUu84tHggK4I3pCtLgCc0QiN7+hQXbTLarbsHL?= =?us-ascii?Q?SB6+5fF1O4kThsJyFYvh239JwvRk7czf4uWyVuAGbn4Rvh7Eh9iq1UpwaiC6?= =?us-ascii?Q?NBrRSVlGNaBlf2zZLmHHofGzJ0S+3xrey8OIPVu3oSVwV9397LB3b/xBN0q8?= =?us-ascii?Q?xeFOw4v2zr6PKuiS8F24rGd7ZiyUdIjE35DC40jCADQzgTbPlb8Lenx4Po4D?= =?us-ascii?Q?aH6EJAuQEDIOPjQT/4HLlQqAJDfgw2WE2jDqrXscUJLnj0gHVd20rGeVdgjL?= =?us-ascii?Q?gXha1m+YJ0szLgZTcxqCAqLCNgkOgfUD71E8lKj5Z9RroFygX1qi4nia7ZT/?= =?us-ascii?Q?e9AzRp0rsJ6zyl9Dd2QcFg2VtLIT5vJUhBluguZbjz2mL47UQjQ4MVYWzhOv?= =?us-ascii?Q?qNlsNwNZ/HLDpimrP4T8sOqNicobO/3T8Pdklxnf7BKIILtTEoZL/nRE0sZ/?= =?us-ascii?Q?HE2f6HYj/sPPMOIda4I1Q+CYmpsek3G34z/VaAzFzgg+Wd9iCSqASembMJZK?= =?us-ascii?Q?XRTWSDG8pPrFGxDvb/HaGYX4NAgFTDdF9U/w/pu14vRYXmCeTwv7CSsQ3LaS?= =?us-ascii?Q?QjSfTyIU3glrKnaStxk+uzQH/ykhQxzRwml8GqOgfxRIDQiZkNg+fAe92QPb?= =?us-ascii?Q?5VENMYDSggtDysMjb7iIGMW0HZiaf18LJo74+DhL6zkLUAfLDOqi4azMgcks?= =?us-ascii?Q?kj2Fi11AfnKwcoQgmkhl8AJC8pxAc0Hh43yMr2Ae4bol+JLGtBletkdLp5il?= =?us-ascii?Q?mhvfwO995hTztWYs9Y2VnMpfZ5KrBCFoD5ozU4wgokl+yCvd/yL71T+GpogK?= =?us-ascii?Q?qbTqLK99SUj8DVC+1hmDRO2xh24BudDfnIaeY8OcTgVmWorBoJb4iaw+j/65?= =?us-ascii?Q?1WFEQlrTym1cMK1ZaKbzRUHPEBS8S0nP/EQrYSM1YccgcSnt1WQFW7UiN0nO?= =?us-ascii?Q?H7HcrPa7pU16vfUxohdtJOXia5fbjZ7PDn04Wja2+NvyAK+wJehl11OgA7aK?= =?us-ascii?Q?316NFY6Xu42pGcYjueMlcmG9P7blEPCyEwpkq3+JZu2uQCwdDKpwT4G8Hhlv?= =?us-ascii?Q?DHxvrYOYRnBWx4vHMYJ9eBd+EcLAxW6iCiIW6iTkxK+vFjRZGj7dsFtq2/zI?= =?us-ascii?Q?A30nmxxhK/Fjhwdv4nIr/fP3Kfns//RbE4k4xdA0nQdvywscElW4MdtnCGhw?= =?us-ascii?Q?+0IssLuDjKom556sjh9Pf/pR8c9lkk0PnudxKgwLBAyfV6mZGl2Hjdss7kR0?= =?us-ascii?Q?o1j2+0dvqVOUpfl3cPmKxFu2T8BZmrUf9w66l8R6rdZTkht5qF9AldohxYJL?= =?us-ascii?Q?LN8ogh+Xq1yDbSMq3BJEeNpwny9v37Dtkvr7uHNGW5ruSNMuQ4PJPLEkIDxR?= =?us-ascii?Q?rYFyG8IyA2/32+SxBdFe22G8QUyMWiqwyZF+v1e5/fJKmfuHNBbMPNS23LP/?= =?us-ascii?Q?9pS7IZ3q8e2K3G1LCkXCYxJQxd/hbNYpqxG1BXaAb0wZ8s55EsGQsbtfbwB8?= =?us-ascii?Q?NaLv692IyAn/IQAdLbSCkhwqd9m3Uy+ptgTWV8lphvjAQ5y4FoaDpwB2u5D5?= =?us-ascii?Q?C9aTMf0PH9wz802CWb5xXcXg1Y/6+fo6vpPgj+ti4Ny7ZRzOiKlBZqF9zn/R?= =?us-ascii?Q?ondIUgeEYC8IVS77aXMvQ0TftAxZVkKdlFwzqTv9RElJfNdI9OHQs/oDbdgg?= =?us-ascii?Q?LQqDJIxnxA=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: ead2cf02-d7d5-4207-e3ce-08df08febfd7 X-MS-Exchange-CrossTenant-AuthSource: PH0PR12MB7957.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Sep 2026 14:30:34.6292 (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: RPR+wSf3a0dh8/MteHWIcPQhcuoSlCsYnIK18/XLgp5p6YCffYNbRfNzcynPUaud4OEJu9KDopMH8zLdm9tbaQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB5783 On Tue, Sep 01, 2026 at 06:32:49PM +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. LGTM overall. Two notes: 1. The two periodic works (GC and the one for "managed" entries) are now per-netns, including their intervals. An unpriv user can set an interval of 0 and hog the CPU. Previously you needed CAP_NET_ADMIN in the init netns. neigh_managed_work() already has a floor for the re-queue delay since commit ed6cd6a17896 ("net, neigh: Set lower cap for neigh_managed_work rearming"). We need something similar for neigh_periodic_work(). Something like: diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 27602bcbeb69..17817e30944b 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -1038,7 +1038,8 @@ static void neigh_periodic_work(struct work_struct *work) * BASE_REACHABLE_TIME. */ queue_delayed_work(system_power_efficient_wq, &tbl->gc_work, - NEIGH_VAR(&tbl->parms, BASE_REACHABLE_TIME) >> 1); + max(NEIGH_VAR(&tbl->parms, BASE_REACHABLE_TIME) >> 1, + HZ)); spin_unlock_bh(&tbl->lock); } 2. Related to the first point, we are now going to schedule periodic work per-netns for "managed" entries which are quite exotic. Better to schedule it only when we have such entries instead of unconditionally from neigh_table_init(). I think both can be done in a follow-up given you are already at 15 patches. The first is more critical, obviously. Thanks!