The LWN.net Weekly Edition for July 18, 2024 is available.

Version 4.2 LTS of the Blender open-source 3D creation suite has been released. Major improvements include a rewrite of the EEVEE render engine, faster rendering, and much more. See the showcase reel for examples of work created by the Blender community with this release. See the text release notes for even more about 4.2 LTS, which will be maintained until July 2026.

Maintenance of the kernel is a difficult, often thankless, task; how it is being handled, the role of maintainers, burnout, and so on are recurring topics at kernel-related conferences. At the 2024 Linux Storage, Filesystem, Memory Management, and BPF Summit, Josef Bacik and Christian Brauner led a session to discuss possible changes to the way filesystems are maintained, though Bacik took the lead role (and the podium). There are a number of interrelated topics, including merging new filesystems, removing old ones, making and testing changes throughout the filesystem tree, and more.

Version 8.4.0 of the digiKam photo editing and management application has been released. This release includes an update of the LibRaw RAW decoder which brings support for many new cameras, a new version of the LensFun toolkit, a feature for automatic translation of image tags, GMIC-Qt 3.4.0, and many bug fixes. See the announcement for full details.

Gustavo A. R. Silva describes the path to safer flexible arrays in the kernel, thanks to the counted_by attribute supported by Clang 18 and GCC 15.

There are a number of requirements to properly use the counted_by attribute. One crucial requirement is that the counter must be initialized before the first reference to the flexible-array member. Another requirement is that the array must always contain at least as many elements as indicated by the counter.

See also: this article from 2023.

Security updates have been issued by Debian (kernel), Fedora (golang and krb5), Red Hat (cups, firefox, git, java-21-openjdk, kernel, linux-firmware, nghttp2, nodejs, and podman), SUSE (libndp, nodejs18, nodejs20, tomcat, and xen), and Ubuntu (gtk+2.0, gtk+3.0 and linux-hwe-5.4, linux-oracle-5.4).

SUSE has, in a somewhat clumsy fashion, asked openSUSE to consider rebranding to clear up confusion over the relationship between SUSE the company and openSUSE as a community project. That, in turn, has opened conversations about revising openSUSE governance and more. So far, there is no concrete proposal to consider, no timeline, or even a process for the community and company to follow to make any decisions.

Amir Goldstein led a filesystem-track session at the 2024 Linux Storage, Filesystem, Memory Management, and BPF Summit on his project to build a hierarchical storage management (HSM) system using fanotify. The idea is to monitor file access in order to determine when to retrieve content from non-local storage (e.g. the cloud). The session was a follow-up to last year's introduction to the project, which covered some of the problems he had encountered; this year, he was updating attendees on its status and progress, along with some other problem areas that he wanted to discuss.

Redox has received a grant to work on implementing POSIX-compatible signals. The draft design calls for them to be implemented nearly completely in user space.

So far, the signals project has been going according to plan, and hopefully, POSIX support for signals will be mostly complete by the end of summer, with in-kernel improvements to process management. After that, work on the userspace process manager will begin, possibly including new kernel performance and/or functionality improvements to facilitate this.

Security updates have been issued by Debian (kernel), Fedora (erlang-jose, mingw-python-certifi, and yt-dlp), Mageia (firefox, nss, libreoffice, sendmail, and tomcat), Red Hat (firefox, ghostscript, git-lfs, kernel, kernel-rt, ruby, and skopeo), SUSE (Botan, cockpit, kernel, nodejs18, p7zip, python3, and tomcat), and Ubuntu (ghostscript, linux, linux-azure, linux-azure-5.15, linux-gcp, linux-gke, linux-gkeop, linux-gkeop-5.15, linux-ibm, linux-intel-iotg, linux-intel-iotg-5.15, linux-kvm, linux-nvidia, linux-oracle, linux-azure-6.5, linux-gcp-6.5, and linux-gke, linux-nvidia).

On June 25, Matthew Wilcox posted a second version of a patch set introducing a new data structure called rosebush, which "is a resizing, scalable, cache-aware, RCU optimised hash table." The kernel already has generic hash tables, though, including rhashtable. Wilcox believes that the design of rhashtable is not the best choice for performance, and has written rosebush as an alternative for use in the directory-entry cache (dcache) — the filesystem cache used to speed up file-name lookup.

The 6.10 kernel was released on July 14 after a nine-week development cycle. This time around, 13,312 non-merge changesets were pulled into the mainline repository — the lowest changeset count since 5.17 in early 2022. Longstanding tradition says that it is time for LWN to gather some statistics on where the new code for 6.10 came from and how it got to the mainline; read on for the details.

Greg Kroah-Hartman has released the 6.6.40 and 6.1.99 stable kernels. Both contain a fix for the USB subsystem; anyone who uses those kernel series and "the XHCI USB host controller driver (i.e. USB 3) must upgrade".

Security updates have been issued by Fedora (cups, krb5, pgadmin4, python3.6, and yarnpkg), Mageia (freeradius, kernel, kmod-xtables-addons, kmod-virtualbox, and dwarves, kernel-linus, and squid), Red Hat (ghostscript, kernel, and less), SUSE (avahi, c-ares, cairo, cups, fdo-client, gdk-pixbuf, git, libarchive, openvswitch3, podman, polkit, python-black, python-Jinja2, python-urllib3, skopeo, squashfs, tiff, traceroute, and wget), and Ubuntu (linux, linux-azure, linux-azure-5.4, linux-bluefield, linux-gcp, linux-gcp-5.4, linux-gkeop, linux-ibm, linux-ibm-5.4, linux-kvm).

Linus has released the 6.10 kernel.

So the final week was perhaps not quite as quiet as the preceding ones, which I don't love - but it also wasn't noisy enough to warrant an extra rc.

Changes in 6.10 include the removal of support for some ancient Alpha CPUs, shadow-stack support for the x32 sub-architecture, Rust-language support on RISC-V systems, support for some Windows NT synchronization primitives (though it is marked "broken" in 6.10), the mseal() system call, fsverity support in the FUSE filesystem subsystem, ioctl() support in the Landlock security module, the memory-allocation profiling subsystem, and more.

See the LWN merge-window summaries (part 1, part 2) and the KernelNewbies 6.10 page for more details.

The GNOME Foundation has announced that executive director Holly Million is stepping down at the end of July, and will be replaced by Richard Littauer as interim executive director:

On behalf of the whole GNOME community, the Board of Directors would like to give our utmost thanks to Holly for her achievements during the past 10 months, including drafting a bold five-year strategic plan for the Foundation, securing two important fiscal sponsorship agreements with GIMP and Black Python Devs, writing our first funding proposal that will now enable the Foundation to apply for more grants, vastly improving our financial operations, and implementing a break-even budget to preserve our financial reserves.

The Foundation's Interim Executive Director, Richard Littauer, brings years of open source leadership as part of his work as an organizer of SustainOSS and CURIOSS, as a sustainability coordinator at the Open Source Initiative, and as a community development manager at Open Source Collective, and through open source contributions to many projects, such as Node.js and IPFS. The Board appointed Richard in June and is confident in his ability to guide the Foundation during this transitional period.

Million says she is leaving to pursue a PhD in psychology. The board plans to announce its search plan for a permanent executive directory after GUADEC, which takes place July 19 through 24.

Linux Mint has released a beta of its next long-term-support (LTS) release, Linux Mint 22 (code-named "Wilma"), based on Ubuntu 24.04. Aside from the standard software updates that come with any major upgrade, some of Wilma's largest selling points are what it doesn't have; namely snap packages or GNOME applications that have broken theming on non-GNOME desktops like Mint's Cinnamon desktop.

Security updates have been issued by Debian (apache2), Fedora (mingw-python3 and python-urllib3), Oracle (dotnet6.0, dotnet8.0, fence-agents, openssh, pki-core, and virt:ol and virt-devel:rhel), SUSE (apache2, firefox, libvpx, oniguruma, python-zipp, python310, thunderbird, and tomcat10), and Ubuntu (apache2, apport, linux, linux-azure, linux-gcp, linux-ibm, linux-intel, linux-lowlatency, linux-oem-6.8, linux-raspi, linux, linux-gcp, linux-nvidia-6.5, linux-raspi, linux-gke, and python-django).

Since the disagreements that led to Eelco Dolstra stepping down from the NixOS Foundation board, there have been a number of projects forked from or inspired by Nix that have stepped up to compete with it. Two months on, some of these projects are now well-established enough to look at what they have to offer and how they compare to each other. Overall, users have a number of good options to choose from, whether they're seeking a compatible replacement for Nix (the configuration language and package manager) or NixOS (the Linux distribution), or something that takes the same ideas in a different direction.

The sixth edition of the Power Management and Scheduling in the Linux Kernel (OSPM) Summit took place on May 30-31 2024, and was graciously hosted by the Institut de Recherche en Informatique de Toulouse (IRIT) in Toulouse, France. This is the first of a series of articles describing the discussions held at OSPM 2024; topics covered include latency hints, energy-aware scheduling, ChromeOS, and user-space schedulers.