Latest Kernel- and Python-Centric LWN Articles

posted by Roy Schestowitz on Jul 17, 2025

• Kernel Space

  • LWN ☛ Kernel API specification and validation

    The kernel project makes a strong promise to its users: the kernel ABI will not be changed in ways that break user-space code. The occasional failure notwithstanding, kernel developers do try to live up to that promise. They are handicapped by one little problem, though: there is no description of what the kernel ABI is, and no comprehensive way to test whether a given change breaks it. The kernel API specification framework proposed (in its second revision) by Sasha Levin addresses some of those concerns, but the solution is incomplete and does not come for free.

    (Note that Levin uses the term "API" rather than "ABI" throughout this work; that term will be used from here on as well.)

    The kernel interface is complex. It includes hundreds of system calls, many of which have complex parameters and behavior; all of that must be completely described if a specification is to be complete. There are other aspects to the API as well, though, including files in /proc or /sys, memory-mapped regions created by the perf-events subsystem or io_uring, and the set of operations available for any given type of file descriptor. Even more complexity comes with the interfaces available to BPF programs or loadable kernel modules, though those are not covered by the kernel's API guarantee. Levin's patch set does not cover all of those areas, but it makes a good start.

  • LWN ☛ Toward the unification of kselftests and KUnit

    The kernel project, for many years, lacked a formal testing setup; it was often joked that testing was the project's main reason for keeping users around. While many types of kernel testing can only be done in the presence of specific hardware, there are other parts of the kernel that could be more widely tested. Over time, though, the kernel has gained two separate testing frameworks and a growing body of automated tests to go with them. These two frameworks — kselftests and KUnit — take different approaches to the testing problem; now this patch series from Thomas Weißschuh aims to bring them together.

  • Collabora ☛ Quick notes from the GStreamer Spring Hackfest 2025

    This past May, we met with the community at the GStreamer Spring Hackfest in Nice, France, and were able to make great strides, including the integration of AI/ML workflows in GStreamer.

• Graphics Stack

  • LWN ☛ A tour of the niri scrolling-tiling Wayland compositor

    Niri is a relatively new Rust-based compositor for Wayland with a different take on tiling window management: windows are placed onscreen in an "infinite" row that can expand beyond the bounds of the visible workspace. It is not a full-blown desktop environment, but niri may be a suitable option for Linux users who want tiling features and the minimalism of a window manager for Wayland.

    Scrollable tiling

    Floating window management is the norm for Linux desktop environments (as well as macOS and Windows), but tiling window management has been around for a long time, arguably as far back as Xerox Star systems in the early 1980s. There are plenty of window managers and compositors that offer tiling for Linux users: awesome, i3, ratpoison, and sway, to name just a few.

    A bit more than 13 years ago, Jesse McClure announced a slightly different approach to tiling window management with the ScrollWM project. It provided a single large virtual desktop ""through which one could scroll smoothly"". Since then, there have been a number of other scrollable tiling implementations, including PaperWM, an extension that enables scrollable tiling of windows for GNOME, which LWN looked at in January.

• Python

  • LWN ☛ Reinventing the Python wheel

    It is no secret that the Python packaging world is at something of a crossroads; there have been debates and discussions about the packaging landscape that started long before our 2023 series describing some of the difficulties. There has been progress since then—and incremental improvements all along, in truth—but a new initiative is looking to overhaul packaging for the language. At PyCon US 2025, Barry Warsaw and Jonathan Dekhtiar gave a presentation on the WheelNext project, which is a community effort that aims to improve the experience for users and providers of Python packages while also working with toolmakers and other parts of the ecosystem to ""reinvent the wheel"". While the project's name refers to Python's wheel binary distribution format, its goals stretch much further than simply the format.

    Warsaw started things off by noting that, while he and Dekhtiar both work for NVIDIA, WheelNext is a ""community-driven initiative that spans all of the entire Python community"". He put up profile pictures from around 30 different people who had already been contributing to the WheelNext GitHub repository; ""it's really open to anybody"", Warsaw said.

  • LWN ☛ Python audio processing with pedalboard

    The pedalboard library for Python is aimed at audio processing of various sorts, from converting between formats to adding audio effects. The maintainer of pedalboard, Peter Sobot, gave a talk about audio in Python at PyCon US 2025, which was held in Pittsburgh, Pennsylvania in May. He started from the basics of digital audio and then moved into working with pedalboard. There were, as might be guessed, audio examples in the talk, along with some visual information; interested readers may want to view the YouTube video of the presentation.

    Sobot works for Spotify as a machine-learning engineer in its audio intelligence lab, so he works on a team using machine-learning models to analyze music. The company has various open APIs that can be used to analyze audio tracks, but it has also released code as open-source software; pedalboard is available under the GPLv3. It has also released open models, such as Basic Pitch, which turns audio data into Musical Instrument Digital Interface (MIDI) files; the model can be used on the web or incorporated into other tools, he said.

• Debian Family

  • LWN ☛ The Software in the Public Interest 2024 annual report

    Software in the Public Interest has released

    its annual report for 2024. It includes reports from the long list of

    projects housed under the SPI umbrella, but the financial statements are

    not included at this time.