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CTRY:US; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:mail.nvidia.com; PTR:dc6edge2.nvidia.com; CAT:NONE; SFS:(13230040)(36860700013)(82310400026)(376014)(1800799024); DIR:OUT; SFP:1101; X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Jun 2025 17:54:35.1967 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: d7a12bf8-ee98-4dd2-149e-08dda2c7b39f X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a; Ip=[216.228.117.161]; Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: SJ1PEPF00002324.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS0PR12MB7945 X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Hi, On Wed, May 28, 2025 at 02:12:37PM +0200, David Marchand wrote: > Hello, > > On Wed, May 28, 2025 at 11:36 AM Maxime Coquelin > wrote: > > > > This patch checks whether the Kernel MTU has the same value > > as the requested one at port configuration time, and skip > > setting it if it is the same. > > > > Doing this, we can avoid the application to require > > NET_ADMIN capability, as in v23.11. > > > > Fixes: 10859ecf09c4 ("net/mlx5: fix MTU configuration") > > Cc: stable@dpdk.org > > > > Signed-off-by: Maxime Coquelin > > --- > > > > Hi Dariuz, > > > > I set priv->mtu as it is done after the mlx5_set_mtu() call, > > but I'm not sure it is necessary, as is the existing call to > > mlx5_get_mtu() because it seems done in mlx5_dev_spawn(). Correct, this additional update of priv->mtu is not needed here. It can be removed. > > It seems there were some back and forth on this priv->mtu topic > between Nelio and other devs in the past. > > Atm, I don't see the need for keeping such a cached mtu value in priv. > There is only one user of the value, and it is for configuration > operation that can do a query to the kernel. I agree. It's not really needed, especially since the same value is also stored in dev->data->mtu, so the kernel query can easily be replaced with reading dev->data->mtu. I'll prepare a patch later which does that. Thanks for bringing that up. For posperity - this cached value is used only during rte_eth_rx_queue_setup() while validating shared RX queue configuration. Best regards, Dariusz Sosnowski