Hírolvasó

Optimizing the kernel's memory use is made much easier if developers have an accurate idea of how memory is being used, but the kernel's instrumentation is not as good as it could be. When Suren Baghdasaryan and Kent Overstreet presented their memory-allocation profiling work, which is meant to address this shortcoming, at the 2023 Linux Storage, Filesystem, Memory Management, and BPF Summit, their objective was uncontroversial but the proposed solution ran into opposition that played out at length on the mailing lists (example) over the last year. So it may be a bit surprising that, when the two returned to the memory-management track in the 2024 gathering, the controversy was gone and the discussion focused on improving details of the implementation.

The AlmaLinux project has announced the formation of the AlmaLinux Engineering Steering Committee (ALESCo):

[It] is dedicated to guiding the technical direction of the AlmaLinux distribution on a day-to-day basis within the guidelines set forth by the board, ensuring its robustness, reliability, sustainability, and relevance in the open-source ecosystem. ALESCo will work collaboratively with, and oversee relevant technical-focused Special Interest Groups (SIGs) to achieve these goals. It is "air traffic control" for engineering matters.

The initial members of ALESCo appointed by the AlmaLinux OS Foundation board are Andrew Lukoshko, Ben Thomas, Cody Robertson, Elkhan Mammadli, Jonathan Wright, and Neal Gompa. The AlmaLinux Wiki has more information on the committee's activities and how to get involved.

The kernel stack is a scarce and tightly constrained resource; kernel developers often have to go far out of their way to avoid using too much stack space. The size of the stack is also fixed, leading to situations where it is too small for some code paths, while wastefully large for others. At the 2024 Linux Storage, Filesystem, Memory Management, and BPF Summit, Pasha Tatashin proposed making the kernel stack size dynamic, making more space available when needed while saving memory overall. This change is not as easy to implement as it might seem, though.

The page structure is a complicated beast, but some parts of it are more intimidating than others. The mapcount field is one of the scarier parts. It allegedly records the number of references to the page in page tables, but, as David Hildenbrand described during the memory-management track at the 2024 Linux Storage, Filesystem, Memory Management, and BPF Summit, things are more complicated than that. Few people truly understand the semantics of this field, but the situation will hopefully get better over time.

Security updates have been issued by AlmaLinux (firefox, nodejs, and thunderbird), Fedora (uriparser), Oracle (firefox and thunderbird), Slackware (mariadb), SUSE (cairo, gdk-pixbuf, krb5, libosinfo, postgresql14, and python310), and Ubuntu (firefox, linux-aws, linux-aws-5.15, and linux-azure).

Az első funkciók majd ősszel válnak használhatóvá.

Az AI-startup beismerően eltávolította a ChatGPT-ből a színésznő hangjára kísértetiesen hajazó hangasszisztensi beállítást.

De a szakértők mégis nagy reményeket fűznek hozzá.

Csak a Max applikáció letöltése után folytatható a megszokott streamelési élmény.

A Meteor Lake lapkák nem teljesítik a Microsoft minimális követelményeit.

A cég mindent felrak az AI-ra, a Copilot+ platformhoz tartozó Surface gépek először Arm-os processzorral kerülnek a boltokba.

There are two fundamental levels of memory allocator in the Linux kernel: the page allocator, which allocates memory in units of pages, and the slab allocator, which allocates arbitrarily-sized chunks that are usually (but not necessarily) smaller than a page. The slab allocator is the one that stands behind commonly used kernel functions like kmalloc(). At the 2024 Linux Storage, Filesystem, Memory Management, and BPF Summit, slab maintainer Vlastimil Babka provided an update on recent changes at the slab level and discussed the changes that are yet to come.

David Vernet kicked off the BPF track at 2024's BPF track at the Linux Storage, Filesystem, Memory Management, and BPF Summit with a talk about polymorphic kfuncs — or, with less jargon, kernel functions that can be called from BPF which use different implementations depending on context. He explained how this would be useful to the sched_ext BPF scheduling framework, but expected it to be helpful in other areas as well.

The term "memory tiering" refers to the management of memory placement on systems with multiple types of memory, each of which has its own performance characteristics. On such systems, poor placement can lead to significantly worse performance. A memory-management-track discussion at the 2024 Linux Storage, Filesystem, Memory Management, and BPF Summit took yet another look at tiering challenges with a focus on upcoming technologies that may simplify (or complicate) the picture.

As the shiny new KDE Plasma 6 desktop makes its way into distribution releases, a small group of developers is still trying to preserve the KDE experience circa 2008. The Trinity Desktop Environment (TDE), is a continuation of KDE 3 that has maintained the old-school desktop with semi-regular releases since 2010. The most recent release, R14.1.2, was announced on April 28. TDE does deliver a usable retro desktop, but with some limitations that hamper its usability on modern systems.

Jens Axboe describes the new io_uring features that will be a part of the 6.10 kernel release.

Bundles are multiple buffers used in a single operation. On the receive side, this means a single receive may utilize multiple buffers, reducing the roundtrip through the networking stack from N per N buffers to just a single one. On the send side, this also enables better handling of how an application deals with sends from a socket, eliminating the need to serialize sends on a single socket. Bundles work with provided buffers, hence this feature also adds support for provided buffers for send operations.

Security updates have been issued by Debian (bind9, chromium, and thunderbird), Fedora (buildah, chromium, firefox, mingw-python-werkzeug, and suricata), Mageia (golang), Oracle (firefox and nodejs:20), Red Hat (firefox, httpd:2.4, nodejs, and thunderbird), and SUSE (firefox, git-cliff, and ucode-intel).

YES! KDE6 landed in OpenBSD -current

Rafael Sadowski (rsadowski@) writes in his most recent blog entry on KDE6 on OpenBSD, and goes on to say

We are currently in an excellent phase ahead of the upcoming OpenBSD release 7.6, which gives us plenty time to thoroughly test KDE Plasma 6. My goal is to make sure it works well and is stable for everyone.

Also worth noting is some still in progress work, Stay tuned for more updates as we progress towards the integration of KDE Plasma 6 into OpenBSD 7.6.

But don't just take our word for it, read the whole thing, KDE6 on OpenBSD over at Rafael's blog. There you will find detailed descriptions of how to perform the upgrade, and a video of the important points.

Non-uniform memory access (NUMA) systems are organized with their CPUs grouped into nodes, each of which has memory attached to it. All memory in the system is accessible from all CPUs, but memory attached to the local node is faster. The kernel's memory-policy ("mempolicy") interface allows threads to inform the kernel about how they would like their memory placed to get the best performance. In recent years, the NUMA concept has been extended to support the management of different types of memory in a system, pushing the limits of the mempolicy subsystem. In a remotely presented session at the 2024 Linux Storage, Filesystem, Memory Management, and BPF Summit, Gregory Price discussed the ways in which the kernel's memory-policy support should evolve to handle today's more-complex systems.

Working on the Linux kernel has always been unlike working on many other software projects. One particularly noticeable difference is the decentralized nature of the kernel's testing infrastructure. Projects such as syzkaller, KernelCI, or the kernel self tests test the kernel in different ways. On February 28, Helen Koike posted a patch set that would add continuous integration (CI) scripts for the whole kernel. The response was generally positive, but several people suggested changes.