Some general networking enhancements are available in UEK 8 with upstream changes that are included from v5.15 to v6.12.

• BIG TCP, which uses bigger TSO/GRO packet sizes for IPv6 traffic, is included to improve the performance when sending large IPv6 TCP packets on data-center networks. Note that this feature isn't enabled by default because it can affect eBPF programs that might assume the TCP header immediately follows the IPv6 header. BIG TCP is enabled by setting the gro_ipv6_max_size and gso_ipv6_max_size on a link device.

• A new socket option SO_RESERVE_MEM is available to provide a mechanism for users to reserve a certain amount of memory for the socket. With this socket option set, the networking stack spends less cycles doing forward alloc and reclaim, which can lead to better system performance, with the cost of an amount of preallocated and irreclaimable memory, even under memory pressure.

• The fair queuing packet scheduler has gained several performance improvements, including a 5% throughput increase in intensive TCP Request/Response (TCP_RR) workload, and 13% increase for UDP packets without a pacing rate set on the socket.

• Several core networking data structures are reorganized for better cache efficiency that can result in TCP performance improvement in where the are many concurrent connections.