5 New Features in Linux 6.3 Kernel

The latest Linux kernel is now available, and it comes with some important new features. Linux Kernel 6.3 is a minor release and it shouldn’t cause any major problems when you get round to upgrading. But like any change you introduce into your environment, it should be properly tested.

So, let’s look at the most important features in this update.

1. User-mode Linux support for Rust

Rust support was added in Linux kernel 6.1, which was released back in December 2022. And this new release brings support for Rust code in user-mode. Essentially, these updates to the kernel make Rust an officially supported language for Linux kernel development, along with C as the primary language.

2. Updated support for Intel and AMD CPUs and graphics hardware

The updated kernel supports technology to be released in upcoming AMD and Intel CPUs and graphics processors. Although some of the changes will also affect current hardware. Kernel 6.3 supports AMD Indirect Branch Restricted Speculation (IBRS). It is a new mitigation for Spectre that doesn’t involve such a hit on performance compared to Retpoline speculative execution.

3. ARM and RISC-V power management

RISC-V architectures now have accelerated string function support thanks to the Zbb bit manipulation extension, which aims to bring code size reduction, performance improvement, and energy reduction to the table.

And ARM gets Scalable Matrix Extension (SME) 2 instructions, which build on previous scalable vector extensions to add new capabilities and performance to improve matrix multiplications that are commonly used in scientific simulations, computer vision, and machine learning (ML) and augmented reality (AR) scenarios.

4. Filesystem improvements for NFS, EXT4m, BRTFS, and EROFS

NFS gets better encryption with the AES-SHA2 standard. There are direct I/O performance optimizations for EXT4, BRTFS now has a faster filesystem driver, and EROFS gets low-latency decompression.  

5. Networking improvements

Kernel 6.3 adds support for Realtek RTL8188EU Wi-Fi cards and Qualcomm Wi-Fi 7 wireless chipsets. NVIDIA BlueField 3 Data Processing Unit (DPU), an infrastructure compute platform with line-rate processing of software-defined networking, storage, and security, gets Ethernet support. And there’s also multi-path TCP support for mixed IPv4 and IPv6 flows.

While the new Linux kernel is available now, if you want to use it, you’ll have to ‘roll your own’ by compiling it yourself. That is until your distro is updated to support kernel 6.3.