The Linux 6.16 kernel is officially out, bringing a host of improvements across networking, security, and hardware support that future versions of Ubuntu will benefit from.

Why the forward-looking phrasing? Because Ubuntu 25.10 will ship with the next kernel, 6.17, which is due out in September.

But what’s included here is still of note. Kernels are cumulative; the performance and feature upgrades Linux 6.16 offers be ‘new’ to those upgrading later this year, and to LTS users who receive that kernel as a HWE upgrade early next year.

Back to now, and Linus Torvalds announced the promotion of Linux 6.16 to stable in the same place he always does, the Linux Kernel Mailing List (LKML), on Sunday July 27, writing:

The release cycle has come to an end. Last week was nice and calm, and there were no big show-stopper surprises to keep us from the regular schedule, so I’ve tagged and pushed out 6.16 as planned. Linus Torvalds

For a whip through the highlights of the latest Linux kernel release, read on.

New Features in Linux 6.16

Networking Boosts

One of the headline features is the new OpenVPN Data Channel Offload (DCO) driver. This will resolve longstanding VPN performance bottlenecks by moving core data channel operations into kernel space, delivering a big boost in throughput, especially for large transfers.

Another networking enhancement, TCP supports sending device memory contents directly ‘to wire’ in Linux 6.16, enabling zero-copy transmission from GPU to the network. It’s not automatic and involves some configuration, but should deliver a performance boost in data-intensive applications.

Five-Level Paging Goes Universal

Five-level page tables are now ‘unconditionally enabled’ in Linux 6.16. Modern CPUs use page tables to translate virtual memory addresses used by applications to physical RAM addresses. The traditional four-level tops out at 256TB, the addition of five levels bumps it to 128PB (petabytes).

As noted in the commit, “ both Intel and AMD CPUs support 5-level paging, which is expected to become more widely adopted in the future. All major x86 Linux distributions have the feature enabled “.

While I don’t think most of us on humble desktop operating systems will need memory limits that large any time soon, the demands of memory-hungry AI and ML workloads make this standardisation an important one in future-proofing Linux.

Security Bolstered

The addition of Intel Trust Domain Extensions (TDX) support brings hardware-level memory encryption to virtual machines running under KVM on Linux, isolating them from (at worst) a compromised host system.

Linux 6.16 kernel also includes hardware-wrapped encryption keys, a security feature previously limited to Android. This protects file system encryption keys by storing them in dedicated security hardware rather than (more vulnerable) system memory.

Elsewhere, the randstruct GCC plugin (able to randomise kernel data structure layouts to foil attackers) is working properly again, and IMA measurements can persist across kexec operations ensuring integrity monitoring between soft reboots.

Filesystem Buffs

“Stupendous” performance improvements arrive in Ext4, which is Ubuntu’s default filesystem, by way of large folio support for regular files. This delivers big speed gains in specific workloads, with the Kernel Test Robot reporting over 37% improvement on large sequential I/O operations.

Meanwhile, the XFS filesystem gains atomic write support for stronger data integrity guarantees, and the FUSE subsystem increases its directory read buffer size to deliver, based on testing by Phoronix, better performance in common scenarios – nice!

And the Bcachefs filesystem now supports only performing rebalance operations (background data-moving tasks) if a device is on AC power. For laptop users, this might be beneficial and help eke out longer battery life.

Hardware Bits

Linux 6.16 includes the usual slew of new hardware support, including lots of ‘bring up’ and ‘initial support’ and ‘further work’ on new AMD, Intel, and ARM devices that most of us won’t be using for a while. Important, but expected and in flux.

But plenty of devices which are available do see new or expanded support in Linux 6.16, including:

Apple Magic Mouse 2 (USB C model) is now supported

(USB C model) is now supported Acer Nitro NGR200 and ByoWave Proteus game controller support

and game controller support Alienware WMI driver integrations with HWMON subsystem

ASUS ROG Ally suspend-and-resume is improved via the ASUS WMI driver

suspend-and-resume is improved via the ASUS WMI driver OneXPlayer handhelds gain controls for charge limits and turbo LEDs

gain controls for charge limits and turbo LEDs Dell DDV driver now exposes battery health and manufacturing data.

now exposes battery health and manufacturing data. ThinkPad users gets hotkey support for camera shutter switch

USB audio devices now support audio offloading, which may allow audio streams to ‘continue to flow’ while the rest of the system sleeps. Kernel dev Greg Kroah-Hartman says this took “the record for the most number of patch series (30+) over the longest period of time (2+ years)” to merge properly.

“This feature offers major power savings on embedded devices […] something that devices running on battery power really care about”, Kroah-Hartman adds.

Beyond that, the intel_pstate driver now registers energy models for energy-aware scheduling on hybrid platforms without SMT, such as Intel Lunar Lake chips.

Other Notable Changes

Beyond the highlights mentioned above there were a few more things to catch my eye:

Obsolete uselib() system call has been removed

system call has been removed KVM support for RISC-V no longer ‘experimental’

no longer ‘experimental’ Bounce buffering support removed

ARM64 gains lazy-preemption and nested virtualisation support

gains lazy-preemption and nested virtualisation support Continued effort to bulk out support for Rust-based kernel drivers

Enable/disable group scheduling of realtime tasks with new CLI option

Faster getrandom() system calls on RISC-V

system calls on RISC-V SELinux gains a cache for directory-access decisions

gains a cache for directory-access decisions Limit on read and write sizes for NFS filesystems increased to 4MB

For more details on this release see the comprehensive merge report recaps (first half & second half) from the wonderful folks at LWN, or scout the thousands of kernel commits on GitHub.

Getting Linux 6.16

Linux 6.16 is available for download from kernel.org as source.

It won’t be packaged for and uploaded to the standard Ubuntu repositories for supported releases officially, but advanced users can choose to install (caveats apply) it using Canonical Mainline DEBs or third-party PPAs unofficially.

Non-repo kernel builds come with no guarantees or support, may lack Ubuntu-specific patches for hardware compatibility or feature integrations, and are unlikely to get timely security patches should any critical vulnerabilities be found.