The kernel's perf events subsystem can produce high-quality profiles, with full function-call chains, of resource usage within the kernel itself. Developers, however, often would like to see profiles of the whole system in one integrated report with, for example, call-stack information that crosses the boundary between the kernel and user space. Support for unwinding user-space call stacks in the perf events subsystem is currently inefficient at best. A long-running effort to provide reliable, user-space call-stack unwinding within the kernel, which will improve that situation considerably, appears to be reaching fruition.

Inside this week's LWN.net Weekly Edition:

• Front: Python packaging; Kernel API specification; Kselftests and KUnit; niri; pedalboard.
• Briefs: Git security fixes; Amarok 3.3; Bash 5.3; Thunderbird 140; tmux-rs; U-Boot 2025.07; Quotes; ...
• Announcements: Newsletters, conferences, security updates, patches, and more.

Versions v2.43.7, v2.44.4, v2.45.4, v2.46.4, v2.47.3, v2.48.2, v2.49.1 and v2.50.1 of the Git source-code management system have been released. "This is a set of coordinated security fix releases. Please update at your earliest convenience". See the announcement for details; many of the vulnerabilities have to do with tricks buried in untrusted repositories.

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.

Security updates have been issued by Debian (djvulibre and slurm-wlm), Red Hat (apache-commons-vfs, container-tools:rhel8, kernel, kernel-rt, podman, python3, rsync, socat, and sudo), SUSE (apache2, helm-mirror, incus, kernel, openssl-3, python-Django, and systemd), and Ubuntu (dcmtk, File::Find::Rule, ghostscript, jquery, and libssh).

The 6.16-rc5 kernel prepatch has been released. Quoth Linus: "Please keep testing, but this all feels fairly regular for this phase of the release".

The 6.15.5, 6.12.36, 6.6.96, and 6.1.143 stable kernels have been released; each contains another set of important fixes.

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.

Inside this week's LWN.net Weekly Edition:

• Front: Kernel features from Python; i686 in Fedora; Kernel development with LLMs; Rust drivers; Load balancing with machine learning; Transparent huge pages.
• Briefs: Bcachefs removal; Coccinelle for Rust; Netdev Foundation; Oracle Linux 10; GNU HHIS 5.0; Rust 1.88.0; Quotes; ...
• Announcements: Newsletters, conferences, security updates, patches, and more.

The Netdev Foundation, which is "a user-led effort under the supervision of the Linux Foundation, focused on financially supporting Linux networking development", has announced its existence.

The initial motivation was to move the NIPA testing outside of Meta, so that more people can help and contribute. But there should be sufficient budget to sponsor more projects.

(NIPA is Netdev Infrastructure for Patch Automation).

The copyleft-next project is an effort to develop a next-generation copyleft license; it was covered here back in 2013 (as well as in 2015 and 2021). The project has stalled in recent years, but now Richard Fontana and Bradley Kuhn have announced a new effort to push copyleft-next forward:

Today, GPLv3 turns exactly 18 years old. This month, GPLv2 turned 34 years old. These are both great licenses and we love them. Nevertheless, at least once in a generation, FOSS needs a new approach to strong copyleft.

Version 5.0 of the GNU Health Hospital Information System has been released. This project, working to support medical offices, shows just how far the free-software effort can reach. Changes in this release include improved reporting and analytics, more comprehensive handling of many types of patient information, a reworked medical-imaging subsystem, better insurance and billing functionality, and more.

The extensible scheduler class ("sched_ext") allows the loading of a custom CPU scheduler into the kernel as a set of BPF functions; it was merged for the 6.12 kernel release. Since then, sched_ext has enabled a wide range of experimentation with scheduling algorithms. At the 2025 Open Source Summit North America, Ching-Chun ("Jim") Huang presented work that has been done to apply (local) machine learning to the problem of scheduling processes on complex systems.

The OsmAnd map and navigation app project recently celebrated its 15th anniversary.

All these 15 years can be roughly divided into three stages. For the first five years, we built the very basic functionality—offline maps and navigation that just worked. Over the next five years, we transformed OsmAnd into a full-fledged application with plugins, extensive settings, and professional tools. We dedicated the third five-year period to deep internal work: completely rewriting and improving key components like the rendering engine and routing algorithms.

Now, a new, fourth stage begins. We have reached functional maturity, and our main goal for the near future is to polish what we've already built. We will focus on stability, speed, and consolidation. User expectations are growing, and what was once considered normal must now be flawless.

(Thanks to Paul Wise).

Security updates have been issued by AlmaLinux (delve, emacs, gimp, gimp:2.8, glibc, idm:DL1, ipa, iputils, kernel, krb5, libarchive, libblockdev, libxml2, mod_proxy_cluster, osbuild-composer, pam, perl-File-Find-Rule, perl-YAML-LibYAML, qt5-qtbase, weldr-client, xorg-x11-server and xorg-x11-server-Xwayland, and xorg-x11-server-Xwayland), Debian (mbedtls and sudo), Oracle (.NET 8.0, delve, delve, golang, firefox, ghostscript, glibc, golang, grafana, iputils, kernel, krb5, libarchive, libblockdev, nodejs22, ruby, thunderbird, tomcat, tomcat9, unbound, and wireshark), Red Hat (glibc and mod_auth_openidc), Slackware (sudo), SUSE (gpg2, ImageMagick, iputils, jakarta-commons-fileupload, kernel, libblockdev, libsoup, open-vm-tools, pam, python-tornado6, screen, sudo, and xwayland), and Ubuntu (linux, linux-aws, linux-gcp, linux-gcp-6.11, linux-hwe-6.11, linux-oracle, linux-raspi, linux-realtime, linux-gcp, linux-gcp-6.8, linux-hwe-5.4, linux-oem-6.11, and sudo).

Linus has released 6.16-rc4 for testing. "Despite a fairly large merge window, things continue to look fairly calm on the rc front".

Version 1.88.0 of the Rust language has been released. Changes include the ability to chain let expressions, "naked" functions that have no compiler-generated prologue or epilogue, automatic garbage collection in cargo, a set of stabilized APIs, and more.

Version 10 of the Oracle Linux distribution has been released.

Oracle Linux 10 is now generally available for 64-bit Intel and AMD (x86_64) and 64-bit Arm (aarch64) platforms. Oracle Linux 10 delivers robust security and exceptional performance for business agility and demanding workloads at cloud scale. Key features include modernized cryptographic capabilities, advancements in developer tooling, and innovations for resilient infrastructure.

Kernel development and machine learning seem like vastly different areas of endeavor; there are not, yet, stories circulating about the vibe-coding of new memory-management algorithms. There may well be places where machine learning (and large language models — LLMs — in particular) prove to be helpful on the edges of the kernel project, though. At the 2025 North-American edition of the Open Source Summit, Sasha Levin presented some of the work he has done putting LLMs to work to make the kernel better

Inside this week's LWN.net Weekly Edition:

• Front: Libxml2; GNOME and systemd; Rust in the kernel; Defconfigs; ngnfs, Free-threaded Python; Asterinas.
• Briefs: LSFMM+BPF book; tag2upload; PostmarketOS 25.06; Firefox 140.0; NLnet funding; Quotes; ...
• Announcements: Newsletters, conferences, security updates, patches, and more.