Networking In The Next Kernel Yields AQtion USB Driver, Retpoline Overhead Reduction

David Miller is one of the latest kernel maintainers sending in his pull requests early for the upcoming Linux 4.21 kernel with its merge window expected to open during the holidays.

With the networking subsystem changes submitted by David Miller, there are a few notable improvements catching our attention for this next version of the Linux kernel.

- The previously covered work for helping mitigate Retpoline overhead in the networking code that was introduced at the start of the year as part of the Spectre Variant Two mitigations with "return trampolines."

- Many cleanups and improvements to the Realtek r8169 driver. The r8169 driver is quite common among many Linux desktop systems and good to see it getting further improved.

- There's a new network driver for the Aquantia Corp's AQtion USB to 2.5/5Gb Ethernet adapters.

- GRO support for plain UDP sockets, which can provide some performance benefits. In one basic benchmark the UDP RX performance went up from 1079 MB/s to 1466 MB/s.

The more comprehensive look at the networking feature changes initially set to land for Linux 4.21 can be found via this pull request.

One notable feature absent from this pull request is WireGuard not yet being queued for Linux 4.21.