On Thu, 16 Mar 2023 12:03:57 +0100 Lorenzo Bianconi wrote: > > I maybe need to dig deeper, but, it looks strange to still > > call_netdevice_notifiers in cases > NETREG_REGISTERED. > > > > Isn't it problematic to call it with NETREG_UNREGISTERED ? > > > > For comparison, netif_set_real_num_tx_queues has this ASSERT_RTNL() only > > under dev->reg_state == NETREG_REGISTERED || dev->reg_state == > > NETREG_UNREGISTERING. > > does it make sense to run call_netdevice_notifiers() in xdp_set_features_flag() > just if dev->reg_state is NETREG_REGISTERED? I was thinking - we'll adjust it if someone complains, but indeed the detection is somewhat weak, a call on a dead device but under rtnl_lock won't warn. Let me just copy what the queue helpers do, exactly, then. > Moreover, looking at the code it seems netdev code can run with dev->reg_state > set to NETREG_UNREGISTERED and without holding RTNL lock, right? You mean - part of unregistration is done without rtnl lock held?
