Linux 7.4 networking adds hardware pacing offload, Meta MPNIC driver, 70% BIG TCP gains

The Linux 7.4 merge window has integrated substantial wired and wireless networking improvements, headlined by hardware pacing offload functionality that delegates packet timing control to NICs and SmartNICs via a new device attribute. The Intel IDPF driver is the first to implement this capability. Performance optimizations include up to 70% throughput gains for mixed BIG TCP and standard TCP paths, plus cache-efficiency and contention-reduction improvements in TCP/IP processing.

New hardware support spans multiple architectures and vendors. Driver additions include the Nebula Matrix NIX, Meta's second-generation MPNIC (with its first-generation FBNIC gaining large IO_uring zero-copy receive buffers), and expanded Qualcomm, Synopsys STMMAC, Realtek, and Mediatek coverage. Wireless work continues on WiFi Aware and WiFi 8 foundations, while Bluetooth gains support for Mediatek MT7928 and Qualcomm QCC2072 chipsets.

Core networking and driver changes in Linux 7.4

• Hardware pacing offload: New pacing_offload network device attribute allows NICs/SmartNICs to manage packet transmission timing directly; IDPF driver is the initial implementation.
• BIG TCP throughput: Mixed BIG TCP and non-big TCP code paths show up to 70% throughput improvement from core networking optimizations.
• TCP/IP performance: Cache usage efficiency improvements and reduced contention in TCP/IP stack processing.
• Meta NIC evolution: New MPNIC driver for Meta's second-generation network interface card; existing FBNIC driver gains large IO_uring zero-copy receive buffer support.
• Platform expansion: STMMAC driver adds Rockchip RK3568 SGMII, Allwinner H616 EMAC1, UltraRISC DP1000, and Qualcomm sa8255p; Realtek RTW88 replaces staging rtl8723bs driver for RTL8723BS; Qualcomm PPE gains IPQ5424 support.

Why it matters

Data center and cloud operators running SmartNICs will benefit from reduced host CPU overhead through pacing offload, while high-throughput applications using BIG TCP see substantial performance gains without hardware changes. The Meta MPNIC driver and IO_uring zero-copy improvements reflect continued investment by hyperscalers in upstream Linux networking, directly benefiting distribution kernels and containerized workloads. Embedded and SBC users gain broader ARM and RISC-V platform support through the STMMAC and Qualcomm driver expansions.