Kicinski: netdev in 2024

Kernel networking maintainer Jakub Kicinski reviews progress in
the networking subsystem in 2024.

Work on relieving the rtnl_lock pressure has continued throughout
the year. The rtnl_lock is often mentioned as one of the biggest
global locks in the kernel, as it protects all of the network
configuration and state. The efforts can be divided into two broad
categories – converting read operations to rely on RCU protection
or other fine grained locking (v6.9, v6.10), and splitting the lock
into per-network namespace locks (preparations for which started in
v6.13).