The LWN.net Weekly Edition for May 23, 2024 is available.

In a combined storage and filesystem session at the 2024 Linux Storage, Filesystem, Memory Management, and BPF Summit, Luis Chamberlain led a discussion on filesystem support for block sizes larger than the usual 4KB page size, which followed up on discussion from last year. While the session was meant to look at the intersection of larger block sizes with atomic block writes that avoid torn (partial) writes (which was also discussed last year), it mostly focused on the filesystem side. Over time, the block sizes offered by storage devices have risen from the original 512 bytes; Chamberlain wanted to discuss filesystem support for block sizes larger than 4KB.

The term "memory model" is used in a couple of ways within the kernel. Perhaps the more obscure meaning is the memory-management subsystem's view of how physical memory is organized on a given system. A proper representation of physical memory will be more efficient in terms of memory and CPU use. Since hardware comes in numerous variations, the kernel supports a number of memory models to match; see this article for details. At the 2024 Linux Storage, Filesystem, Memory-Management and BPF Summit, Oscar Salvador, presenting remotely, made the case for removing one of those models.

Compute Express Link (CXL) is a data-center-oriented memory solution that, according to some in the industry, will yield large cost savings and performance improvements. Others are more skeptical. At the 2024 Linux Storage, Filesystem, Memory-Management and BPF Summit, two sessions covered CXL and how it will be supported in future kernels.

For every page of memory in the system, the kernel maintains a set of page flags describing how the page is used and various aspects of its current state. Space for page flags has been in chronic short supply, leading to a desire to eliminate or consolidate them whenever possible. That objective, though, is hampered by the fact that the purpose of many page flags is not well understood. In a memory-management-track session at the 2024 Linux Storage, Filesystem, Memory-Management and BPF Summit, Matthew Wilcox set out to cooperatively update the page-flag documentation to improve that situation.

The problem of sharing page tables across processes has been discussed numerous times over the years, Khaled Aziz said at the beginning of his 2024 Linux Storage, Filesystem, Memory-Management and BPF Summit session on the topic. He was there to, once again, talk about the proposed mshare() system call (which, in its current form, is no longer actually a system call but the feature still goes by that name) and to see what can be done to finally get it into the mainline.

Comme son titre l'indique, Furiosa : Une saga Mad Max est centré sur le personnage Furiosa, incarné par Anya Taylor-Joy (et Charlize Theron dans Fury Road). C'est le premier épisode sans Max Rockatansky. Ou presque ?

The kernel's hugetlbfs subsystem was the first mechanism by which the kernel made huge pages available to user space; it was added to the 2.5.46 development kernel in 2002. While hugetlbfs remains useful, it is also viewed as a sort of second memory-management subsystem that would be best unified with the rest of the kernel. At the 2024 Linux Storage, Filesystem, Memory-Management and BPF Summit, Peter Xu raised the question of what that unification would involve and what the first steps might be.

KeePassXC is an open-source (GPLv3), cross-platform password manager with local-only data storage. The project comes with a number of build options that can be used to toggle optional features, such as browser integration and password database sharing. However, controversy ensued when Debian Developer Julian Klode decided to make use of these compile flags to disable these features to improve security in the keepassxc package uploaded to Debian unstable for the upcoming Debian 13 ("Trixie") release.

Washington a accusé la Russie d'avoir déployé une nouvelle arme dans l'espace, capable de s'en prendre aux satellites. Elle aurait été envoyée à la mi-mai.

The 2024 Linux Storage, Filesystem, Memory-Management and BPF Summit was a development conference, where discussion was prioritized and presentations with a lot of slides were discouraged. Paul McKenney seemingly flouted this convention in a joint session of the storage, filesystem, and memory-management tracks where he presented about 50 slides — in five minutes, twice. The subject was the use of the read-copy-update (RCU) mechanism in the memory-reclaim process, and whether changes to RCU would be needed for that purpose.

Version 3.20.0 of the Alpine Linux distribution has been released with initial support for 64-bit RISC-V. Other important changes include updates to GNOME 46, KDE Plasma 6, and replacing Redis with Valkey due to Redis's adoption of a non-free license model. See the release notes for more on this release.

Double écran OLED d'une luminosité incroyable, finesse de tous les records, processeur Apple M4 surpuissant, Magic Keyboard presque aussi bon que le clavier d'un MacBook… Sur le papier, l'iPad Pro de 2024 est le produit le plus avancé d'Apple. Mais son système d'exploitation et ses applications manquent encore de maturité.

[Deal du Jour] Les souris classiques à la forme bombée ne sont pas les plus ergonomiques qui soient. La Logitech MX Vertical est un modèle doté d'un design qui épouse la position naturelle de la main. En promotion, elle vaut le coup de s'y intéresser.

Pour vaincre Chronos dans Hades 2, tous les moyens sont bons. Vous pouvez même vous faire aider de familiers, ces animaux de compagnie que l'on peut apprivoiser pour en faire des alliés. À chaque run, Mélinoé peut être accompagnée d'un animal. Ce n'est pas que mignon : ils sont utiles au combat. Voilà ce qu'il faut faire pour les débloquer.

Sortie discrètement sur Netflix durant le mois de mai, The 8 Show s’est rapidement hissée au sommet du top 10 de la plateforme. Ce drama coréen met nos nerfs à rude épreuve avec un jeu d’argent aux conséquences dramatiques. Un concept qui n’est pas sans rappeler celui de Squid Game, mais seulement en apparence.

Looking up a virtual memory area (VMA) in a process's address space, for the handling of page faults or any of a number of other tasks, in multi-threaded processes has long been bedeviled by lock contention in the kernel. As a result, developer gatherings have been subjected to many sessions on how to improve the situation. At the 2024 Linux Storage, Filesystem, Memory-Management and BPF Summit, developers in the memory-management track met, in a session led by Liam Howlett, to talk about a situation that has improved considerably in recent times, but which still offers opportunities for optimization.

Security updates have been issued by Debian (webkit2gtk), Fedora (kernel), Mageia (chromium-browser-stable, djvulibre, gdk-pixbuf2.0, nss & firefox, postgresql15 & postgresql13, python-pymongo, python-sqlparse, stb, thunderbird, and vim), Red Hat (go-toolset:rhel8, nodejs, and varnish:6), SUSE (gitui, glibc, and kernel), and Ubuntu (libspreadsheet-parseexcel-perl, linux-aws, linux-aws-5.15, linux-gke, linux-gcp, python-idna, and thunderbird).

Vineeth Pillai gave a remote talk at the 2024 Linux Storage, Filesystem, Memory Management, and BPF Summit explaining how BPF could be used to improve the performance of virtual machines (VMs). Pillai has a patch set designed to let guest and host machines share scheduling information in order to eliminate some of the overhead of running in a VM. The assembled developers had several comments on the design, but seemed overall to approve of the prospect.