LinuxChanges - Linux Kernel Newbies (original) (raw)

Changes done in each Linux kernel release. Other places to get news about the Linux kernel are LWN kernel status or the Linux Kernel mailing list (there is a web interface in www.lkml.org or lore.kernel.org/lkml). The lore.kernel.org/lkml/ archive is also available via NTTP if you prefer to use a newsreader: use nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel for that. List of changes of older releases can be found at LinuxVersions. If you're going to add something here look first at LinuxChangesRules!

Linux 6.19 was released on Sunday, 8 February 2026

Summary: Linux 6.19 adds a new listns(2) system call that makes much easier to list the namespaces present on the system; support for the Live Update Orchestrator, which allows to reboot a kernel via kexec while enough kernel state to allow virtual virtual machines continue working after a reboot; support for PCIe Link Encryption which lets PCIe devices encrypt its communication with confidential VMs; Btrfs support for the experimental shutdown ioctl and suspension during scrub or device replaces; Ext4 support for block devices larger than page size and faster online defragmentation; support for the color pipeline API for better and faster HDR graphics; improvements to io_uring; and support for the SFrame format that brings faster frame unwinding. As always, there are many other features, new drivers, improvements and fixes.

You might also be interested in the list of changes done by LWN: merge window part 1, part 2

Contents

  1. Prominent features
    1. New listns(2) system call to list namespaces
    2. Live update orchestrator
    3. Support for PCIe Link Encryption
    4. Btrfs improvements
    5. Ext4 support for block sizes larger than page size
    6. Add color pipeline API, sharpness property, plus other graphic updates
    7. io_uring updates
    8. SFrame support for faster frame unwinding
  2. Core (various)
  3. File systems
  4. Memory management
  5. Block layer
  6. Tracing, perf and BPF
  7. Virtualization
  8. Cryptography
  9. Security
  10. Networking
  11. Architectures
  12. Drivers
  13. Graphics
  14. Power Management
  15. Storage
  16. Drivers in the Staging area
  17. Networking
  18. Audio
  19. Tablets, touch screens, keyboards, mouses
  20. TV tuners, webcams, video capturers
  21. Universal Serial Bus
  22. Serial Peripheral Interface (SPI)
  23. Watchdog
  24. Serial
  25. CPU Frequency scaling
  26. Voltage, current regulators, power capping, power supply
  27. Real Time Clock (RTC)
  28. Pin Controllers (pinctrl)
  29. Multi Media Card (MMC)
  30. Memory Technology Devices (MTD)
  31. Industrial I/O (iio)
  32. Multi Function Devices (MFD)
  33. Pulse-Width Modulation (PWM)
  34. Inter-Integrated Circuit (I2C + I3C)
  35. Hardware monitoring (hwmon)
  36. General Purpose I/O (gpio)
  37. Leds
  38. Hardware Random Number Generator (hwrng)
  39. Cryptography hardware acceleration
  40. PCI
  41. Clock
  42. PHY ("physical layer" framework)
  43. EDAC (Error Detection And Correction)
  44. IOMMU
  45. Accel
  46. Various
  47. List of Pull Requests
  48. Other news sites

1. Prominent features

1.1. New listns(2) system call to list namespaces

There was no direct way for userspace programs on Linux to enumerate namespaces in the system. Applications must resort to scanning /proc//ns/ across all processes, which is inefficient, incomplete, permission-heavy, there is no ordering or ownership, no filtering...this release incorporates a new system call, listns(2), which solves these problems by providing direct kernel-level enumeration of namespaces. It is similar to listmount() but tailored to namespaces

Recommended LWN article: Namespace reference counting and listns()

1.2. Live update orchestrator

This series introduces the Live Update Orchestrator, a kernel subsystem designed to facilitate live kernel updates using a kexec-based reboot. This has been designed primarily to allows virtual machines to continue working after the reboot with minimal downtime, a capability that is critical for cloud environments, but LUO is designed to be workload-agnostic. LUO achieves these goals by preserving the state of selected resources, such as memory, devices and their dependencies, across the kernel transition.

Recommended LWN article: Kexec handover and the live update orchestrator

This release adds support to enable PCIe Link Eencryption and secure Device Authentication. This encryption can be used to communicate confidential VMs (like AMD SEV-SNP or Intel TDX): the PCIe traffic between the VM and the device is encrypted and authenticated on the wire, so the host OS or other devices cannot snoop on DMA traffic, observe or inject data

1.4. Btrfs improvements

This release includes a few important improvements for the Btrfs file system: scrub and device replacement no longer block attempts to suspend the system (scrub records the last state and can continue from there; the device replacement has to be restarted from the beginning); adds support for the shutdown ioctl, improves the (experimental) support for block sizes being larger than the memory page size in RAID56 setups; and it also includes preparations for fscrypt support and some locking performance improvements when the file system is processing space reservation tickets

1.5. Ext4 support for block sizes larger than page size

This release enables support for file system block sizes that are larger than the computer page size (4KB in x86). Larger block sizes have advantages and disadvantages, on the advantage size it can improve buffered IO write performance by about 50% on average (direct IO shows some degradation, due to the increased time spent doing checksums - larger block sizes are not always better). Benchmark details can be found here. This release also optimizes and greatly improves the throughput of online defragment.

1.6. Add color pipeline API, sharpness property, plus other graphic updates

This release adds support in the graphic driver layer for color pipeline. This API supports pre-, and post-blending complex color transformations in display controller hardware in order to allow for HW-supported HDR use-cases, as well as to provide support to color-managed applications, such as video or image editors.

It is possible to support an HDR output on HW, but that requires the compositor or application to render and compose the content into one final buffer intended for display. Doing so is costly. Most modern display hardware supports varios methods to do color transformations, faster and more power efficient than performing similar operations via shaders or CPU. The color pipeline API allows to make use of this hardware functionality to support complex color transformations with no, or minimal CPU or shader load.

There are also other updates done to the graphic layer, such as the sharpness property, which can be set by userspace with desired sharpness strength, which enables adaptive sharpening filter for Intel LNL onwards. There is also a new Arm Ethos NPU accelerator driver, initial Xe3P support in xe, or support in the amdgpu driver for discrete SI/CIK cards (that were previously only support by radeon), which enables vulkan support in userspace for them.

1.7. io_uring updates

As with many other releases, this one includes a few updates to io_uring. This release adds:

1.8. SFrame support for faster frame unwinding

The kernel needs to unwind stacks for some tools like perf. One of the most common solutions is to use frame pointers, but that solution degrades performance. Another solution is to use DWARF debugging information, but it's a complex format that it's too slow to parse. There has been work to design a new format, SFrame, which has been implemented by GCC (and LLVM in the future) and binutils. This format contains the minimal information to allow fast stack tracing, and support has been added for it in this release.

Recommended LWN article: https://lwn.net/Articles/1029189/SFrame-based stack unwinding for the kernel

2. Core (various)

3. File systems

4. Memory management

5. Block layer

6. Tracing, perf and BPF

7. Virtualization

8. Cryptography

9. Security

10. Networking

11. Architectures

12. Drivers

12.1. Graphics

12.2. Power Management

12.3. Storage

12.4. Drivers in the Staging area

12.5. Networking

12.6. Audio

12.7. Tablets, touch screens, keyboards, mouses

12.8. TV tuners, webcams, video capturers

12.9. Universal Serial Bus

12.10. Serial Peripheral Interface (SPI)

12.11. Watchdog

12.12. Serial

12.13. CPU Frequency scaling

12.14. Voltage, current regulators, power capping, power supply

12.15. Real Time Clock (RTC)

12.16. Pin Controllers (pinctrl)

12.18. Memory Technology Devices (MTD)

12.19. Industrial I/O (iio)

12.20. Multi Function Devices (MFD)

12.21. Pulse-Width Modulation (PWM)

12.22. Inter-Integrated Circuit (I2C + I3C)

12.23. Hardware monitoring (hwmon)

12.24. General Purpose I/O (gpio)

12.25. Leds

12.26. Hardware Random Number Generator (hwrng)

12.27. Cryptography hardware acceleration

12.28. PCI

12.29. Clock

12.30. PHY ("physical layer" framework)

12.31. EDAC (Error Detection And Correction)

12.32. IOMMU

12.33. Accel

12.34. Various

13. List of Pull Requests

14. Other news sites