> One difference from VLAN is that in that case, the entire > register_vlan_device() function runs under RTNL. > When those bugs that you talk about are found, who starts using the > network interface too early? User space or someone else? Would RTNL be > enough to avoid that?
NFS root. Registering the interface causes autoconfig to start, sending a DHCP request, or if the IP addresses are fixed, it could send an ARP for the NFS server. It is just nice to have if it is before register_netdev(). I don't think there is an actual issues in this case, being able to send/receive packets should not depend on the upper/lower linkage for DSA. Andrew