RE: [Intel-wired-lan] [PATCH net-next v2 03/13] net: introduce ndo_set_rx_mode_async and dev_rx_mode_work
From: Loktionov, Aleksandr <hidden>
Date: 2026-03-23 12:09:55
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-----Original Message----- From: Intel-wired-lan <redacted> On Behalf Of Stanislav Fomichev Sent: Wednesday, March 18, 2026 4:03 PM To: netdev@vger.kernel.org Cc: davem@davemloft.net; edumazet@google.com; kuba@kernel.org; pabeni@redhat.com; horms@kernel.org; corbet@lwn.net; skhan@linuxfoundation.org; andrew+netdev@lunn.ch; michael.chan@broadcom.com; pavan.chebbi@broadcom.com; Nguyen, Anthony L [off-list ref]; Kitszel, Przemyslaw [off-list ref]; saeedm@nvidia.com; tariqt@nvidia.com; mbloch@nvidia.com; alexanderduyck@fb.com; kernel-team@meta.com; johannes@sipsolutions.net; sd@queasysnail.net; jianbol@nvidia.com; dtatulea@nvidia.com; sdf@fomichev.me; mohsin.bashr@gmail.com; Keller, Jacob E [off-list ref]; willemb@google.com; skhawaja@google.com; bestswngs@gmail.com; linux-doc@vger.kernel.org; linux-kernel@vger.kernel.org; intel-wired-lan@lists.osuosl.org; linux- rdma@vger.kernel.org; linux-wireless@vger.kernel.org; linux- kselftest@vger.kernel.org; leon@kernel.org Subject: [Intel-wired-lan] [PATCH net-next v2 03/13] net: introduce ndo_set_rx_mode_async and dev_rx_mode_work Add ndo_set_rx_mode_async callback that drivers can implement instead of the legacy ndo_set_rx_mode. The legacy callback runs under the netif_addr_lock spinlock with BHs disabled, preventing drivers from sleeping. The async variant runs from a work queue with rtnl_lock and netdev_lock_ops held, in fully sleepable context. When __dev_set_rx_mode() sees ndo_set_rx_mode_async, it schedules dev_rx_mode_work instead of calling the driver inline. The work function takes two snapshots of each address list (uc/mc) under the addr_lock, then drops the lock and calls the driver with the work copies. After the driver returns, it reconciles the snapshots back to the real lists under the lock. Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> --- Documentation/networking/netdevices.rst | 8 +++ include/linux/netdevice.h | 20 ++++++ net/core/dev.c | 94 +++++++++++++++++++++++- - 3 files changed, 115 insertions(+), 7 deletions(-)diff --git a/Documentation/networking/netdevices.rstb/Documentation/networking/netdevices.rst index 35704d115312..dc83d78d3b27 100644--- a/Documentation/networking/netdevices.rst +++ b/Documentation/networking/netdevices.rst@@ -289,6 +289,14 @@ struct net_device synchronization rules ndo_set_rx_mode: Synchronization: netif_addr_lock spinlock. Context: BHs disabled
...
-/*
- * Upload unicast and multicast address lists to device and
- * configure RX filtering. When the device doesn't support unicast
- * filtering it is put in promiscuous mode while unicast addresses
- * are present.
+static void dev_rx_mode_work(struct work_struct *work) {
+ struct net_device *dev = container_of(work, struct net_device,
+ rx_mode_work);
+ struct netdev_hw_addr_list uc_snap, mc_snap, uc_ref, mc_ref;
+ const struct net_device_ops *ops = dev->netdev_ops;
+ int err;
+
+ __hw_addr_init(&uc_snap);
+ __hw_addr_init(&mc_snap);
+ __hw_addr_init(&uc_ref);
+ __hw_addr_init(&mc_ref);
+
+ rtnl_lock();
+ netdev_lock_ops(dev);
+
+ if (!netif_up_and_present(dev))
+ goto out;
+
+ if (ops->ndo_set_rx_mode_async) {
+ netif_addr_lock_bh(dev);
+
+ err = __hw_addr_list_snapshot(&uc_snap, &dev->uc,
+ dev->addr_len);
+ if (!err)
+ err = __hw_addr_list_snapshot(&uc_ref, &dev->uc,
+ dev->addr_len);
+ if (!err)
+ err = __hw_addr_list_snapshot(&mc_snap, &dev->mc,
+ dev->addr_len);
+ if (!err)
+ err = __hw_addr_list_snapshot(&mc_ref, &dev->mc,
+ dev->addr_len);
+ netif_addr_unlock_bh(dev);
+
+ if (err) {
+ __hw_addr_flush(&uc_snap);
+ __hw_addr_flush(&uc_ref);
+ __hw_addr_flush(&mc_snap);Shouldn't here go cleanup for symmetry? __hw_addr_flush(&mc_ref);
+ goto out; + } + + ops->ndo_set_rx_mode_async(dev, &uc_snap, &mc_snap); + + netif_addr_lock_bh(dev); + __hw_addr_list_reconcile(&dev->uc, &uc_snap, + &uc_ref, dev->addr_len); + __hw_addr_list_reconcile(&dev->mc, &mc_snap, + &mc_ref, dev->addr_len); + netif_addr_unlock_bh(dev); + } + +out: + netdev_unlock_ops(dev); + rtnl_unlock(); +}
...
-- 2.53.0