We have just received the sad news that longtime core BSD developer Mike Karels has died; he will certainly be missed.

Version 6.2 of the Incus container-management system is out. "This release contains the second wave of changes contributed by students of the University of Texas at Austin and a few other features and improvements." The features include a new incus top command, a new API for system load information, and more.

In the recent discussion on commenting at LWN, several readers asked for the ability to hide subthreads of a long comment stream. That feature has just been added; it is also integrated with the three comment-display modes and with comment filtering, removing the need for JavaScript for filtering. Hiding is not persistent; no extra data is stored at either end.

Give it a try; if you have comments on the new mechanism, this is the place to put them.

Security updates have been issued by Mageia (chromium-browser-stable, git, libreoffice, microcode, python-requests, webkit2, and wireshark), Oracle (container-tools:ol8, glibc, go-toolset:ol8, idm:DL1 and idm:client, less, python39:3.9 and python39-devel:3.9, ruby:3.0, and virt:ol and virt-devel:rhel), Red Hat (nodejs, nodejs:18, python-idna, and ruby:3.1), and SUSE (389-ds, ffmpeg, ffmpeg-4, gnutls, gstreamer-plugins-base, libhtp, mariadb104, poppler, python-python-jose, squid, and unbound).

The second 6.10 kernel prepatch is out for testing. "Nothing feels particularly odd, but rc2 is usually fairly small and people are only starting to find regressions. So please go test some more."

The "pidfdfs" virtual filesystem was added to the 6.9 kernel release as a way to export better information about running processes to user space. It replaced a previous implementation in a way that was, on its surface, fully compatible while adding a number of new capabilities. This transition, which was intended to be entirely invisible to existing applications, already ran into trouble in March, when a misunderstanding with SELinux caused systems with pidfdfs to fail to boot properly. That problem was quickly fixed, but it turns out that there was one more surprise in store, showing just how hard ABI compatibility can be at times.

The 2024 Kernel Maintainers Summit will happen on September 17 in Vienna, Austria; it is an invitation-only event for a small group to discuss important kernel-development problems. The call for proposals for this gathering has now been posted. One of the best ways to be invited to the event is to propose a topic that needs discussion in that forum. The deadline for proposals is June 18.

The developers of the Krita painting application are celebrating 25 years of development with a detailed history of the project.

A quarter century. That's how long we've been working on Krita. Well, what would become Krita. It started out as KImageShop, but that name was nuked by a now long-dead German lawyer. Then it was renamed to Krayon, and that name was also nuked. Then it was renamed to Krita, and that name stuck.

The LWN.net Weekly Edition for May 30, 2024 is available.

When redesigning the LWN site in 2002, we thought long and hard about whether the ability to post comments should be part of it; LWN had not offered that feature for the first four years of its existence. There were already plenty of examples of how comments can go bad by then, but we decided to trust our readers to keep things under control. Much of the time, that trust has proved justified, but there have been times where things have not gone so well. This time is quickly becoming one of those others.

In the final session in the memory-management track of the 2024 Linux Storage, Filesystem, Memory-Management and BPF Summit, the exhausted group of developers looked one more time at the use of huge pages and the associated problem of memory fragmentation. At its worst, this problem can make huge pages harder (and more expensive) to allocate. Luis Chamberlain, who ran the session, felt that people were worried about this problem, but that there was little data on how severe it truly is.

A longstanding tradition in the memory-management track of the Linux Storage, Filesystem, Memory-Management and BPF Summit is a session with maintainer Andrew Morton to discuss the overall state of the community and the development process. The 2024 gathering upheld that tradition toward the end of the final day of the event. It seems that Morton and the assembled developers were all happy with how memory-management work is going, but there is always room for improvement.

Security updates have been issued by Debian (less), Mageia (chromium-browser-stable), SUSE (apache2, java-1_8_0-openj9, kernel, libqt5-qtnetworkauth, and openssl-3), and Ubuntu (netatalk and python-cryptography).

Geoff Huston suggests that it is time to give up on DNSSEC and look for a better way to secure the Internet namespace.

What appears to be very clear (to me at any rate!) is that DNSSEC as we know it today is just not going anywhere. It's too complex, too fragile and just too slow to use for the majority of services and their users. Some value its benefits highly enough that they are prepared to live with its shortcomings, but that's not the case for the overall majority of name holders and for the majority of users, and no amount of passionate exhortations about DNSSEC will change this.

One of the long-term goals of the folio conversion in the kernel's memory-management subsystem is the replacement of the page structure, which describes a page of physical memory, with an eight-byte "memory descriptor". This change would reduce the overhead of tracking physical memory, increase type safety, and make memory management more flexible. Thus far, though, details on what the memory-descriptor future will look like have been relatively scarce. At the 2024 Linux Storage, Filesystem, Memory-Management and BPF Summit, Matthew Wilcox led a discussion to try to fill in the picture somewhat.

Linus Torvalds released 6.10-rc1 and closed the 6.10 merge window on May 26. By that time, 11,534 non-merge changesets had been pulled into the mainline for the next release; nearly 5,000 of those came in after "The first half of the 6.10 merge window" was written. While the latter half of the merge window tends to focus more on fixes, there was also a lot of new functionality that landed during this time.

The maple tree data structure was added during the 6.1 development cycle; since then, it has taken its place at the core of the kernel's memory-management subsystem. Unsurprisingly, work on maple trees is not yet done. Maple-tree maintainer Liam Howlett ran a session in the memory-management track of the 2024 Linux Storage, Filesystem, Memory-Management and BPF Summit to discuss the current state of the maple tree and which features can be expected next.

Linus has released 6.10-rc1 and closed the merge window for this release. For reasons that have not been spelled out, the codename for the release has been changed to "Baby Opossum Posse".

Using huge pages has been known for years to improve the performance of many workloads. But traditional huge pages, often sized by the CPU at 2MB, can be difficult to allocate and can waste memory due to internal fragmentation. Driven by both the folio transition and hardware improvements, attention to smaller, multi-size transparent huge pages (mTHPs) has been on the rise. In two memory-management-track sessions at the 2024 Linux Storage, Filesystem, Memory-Management and BPF Summit, developers discussed the kernel's ability to reliably allocate mTHPs and the performance gains that result.