Linux 6.4 Has Many Networking Changes From A New Performance Tunable To More WiFi 7

With Linux running on everything from tiny single board computers with basic WiFi or Ethernet networking up through massive super-computer clusters, the Linux networking subsystem continues seeing immense improvements each kernel cycle. With Linux 6.4 the networking changes are heavy from new hardware support (including Apple M1 Pro/Max WiFi!) to continued work around WiFi 7 support as well as never-ending work on performance optimizations.

The Linux 6.4 networking changes were submitted and already pulled into Linux Git. Some of the feature highlights on the networking side for this next kernel version include:

- A new configuration option "MAX_SKB_FRAGS" is added that when increasing it can yield better BIG TCP performance. The option can allow for fitting up to 45 segments per SKB and that value has already been in use at Google for "years" according to engineer Eric Dumazet who submitted the patch for upstream. The /proc/sys/net/core/max_skb_frags default value is maintained at 17 until there is more test coverage for a better updated default value and for not causing any driver problems.

- Intel's "iwlwifi" WiFi driver has seen preparations for WiFi 7 EHT support and multi-link support.

- The MediaTek MT76 driver has added WiFi 7 support.

- With the Linux kernel's networking core code, WiFi 7 (EHT) mesh support is now enabled.

- Numerous new (e)BPF features for developers.

- Optimized route lookup for IPv6 addresses.

- Fair Capacity Scheduler and Weighted Fair Queuing Scheduler stream schedulers have been added to the SCTP code.

- AMD Pensando core device Ethernet support has been added. AMD Pensando SoC support continues working on upstreaming.

- Ethernet support added for the following SoCs: MediaTek MT7981, MediaTek MT7988, Broadcom BCM53134, Qualcomm EMAC3 DWMAC, and StarFive JH7110 RISC-V.

- WiFi support for the Apple M1 Pro and Apple M1 Max devices.

- Realtek rtl8710bu/rtl8188gu, rtl8822bs, rtl8822cs and rtl8821cs WiFi hardware support.

- Intel's 100G ICE network driver has seen work to support Scalable IOV. Intel's i40e driver meanwhile added XDP multi-buffer support.

- SDIO bus suport for the Realtek RTW88 driver.

- The Realtek RTW89 driver has better support for 6GHz scanning.

- Various networking improvements around zero-copy handling.

- Various other performance/efficiency optimizations with threading enhancements, optimized struct layouts, etc.

More details on the massive amount of Linux networking changes for the v6.4 kernel cycle via this mailing list post.