Linux 6.3 Introduces IPv4 "BIG TCP" To Improve High Speed Network Performance

The networking subsystem feature updates for the Linux 6.3 kernel were submitted today that feature not only some prominent networking driver enhancements and new wired/wireless hardware support but also core networking improvements like BIG TCP for IPv4.

The Linux kernel since last year already supports BIG TCP for IPv6 traffic to allow for larger TSO/GRO packet sizes. This has yielded significant speed-ups for IPv6 performance particularly in the 25~100+ Gbit networking space while also yielding lower latencies. With Linux 6.3, similar benefits are now being provided in the IPv4 space.

Benchmarks shown in the IPv4 BIG TCP patch series show some very nice improvements out of enabling BIG TCP.

With Linux 6.3, the IPv3 BIG TCP support is now available to allow for better networking throughput performance and lower latencies particularly in data centers with very high speed network adapters. When it comes to IPv6 BIG TCP, the Linux 6.3 kernel also extends the Intel ICE driver to support the feature. More background information on BIG TCP for those interested can be found via this Netdev 0x15 presentation.

Some of the other key networking changes in Linux 6.3 include supporting minimal WiFi 7 Extremely High Throughput (EHT) reporting, WiFi 7 EHT channel puncturing support, removing static WEP support, BPF trampoline support on s390x and RISC-V 64-bit hardware, various other BPF enhancements, and much more.

When it comes to the network drivers in Linux 6.3 there is NVIDIA BlueField 3 DPU Ethernet support, i.MX93 SoC support, Qualcomm WiFi 7 device support with ath12k (more details on that in its own article shortly), and Realtek RTL8188EU WiFi adapter support.

The full list of networking changes for the Linux 6.3 merge window can be found via this pull request.