All posts by corbet

[$] Committing to Rust in the kernel

Post Syndicated from corbet original https://lwn.net/Articles/991062/

The project to enable the writing of kernel code in Rust has been underway
for several years, and each kernel release includes more Rust code. Even
so, some developers have expressed frustration at the time it takes to get
new functionality merged, and an air of uncertainty still hangs over
the project. At the 2024 Maintainers Summit, Miguel Ojeda led a discussion
on the status of Rust in the kernel and whether the time had come to stop
considering it an experimental project. There were not answers to all of the
questions, but it seems clear that Rust in the kernel will continue
steaming ahead.

Security updates for Tuesday

Post Syndicated from corbet original https://lwn.net/Articles/991492/

Security updates have been issued by Gentoo (GCC, Hunspell, Tor, and ZNC), SUSE (apr-devel, cargo-c, chromedriver, firefox, kernel, libecpg6, libmfx, onefetch, postgresql12, postgresql13, postgresql14, postgresql15, postgresql16, python310-azure-identity, python39, qemu, rage-encryption, stgit, and system-user-zabbix), and Ubuntu (kernel, linux-ibm-5.15, linux-oracle-5.15, linux-xilinx-zynqmp, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-raspi, and py7zr).

[$] Tools for kernel developers

Post Syndicated from corbet original https://lwn.net/Articles/991033/

Konstantin Ryabitsev started a session on development tooling at the 2024
Maintainers Summit by saying that he does not want to be a “wrecking ball”.
If a given workflow is working for people, he does not want to try to force
any sort of change. That said, he has ideas for how he can continue his
work on providing better tooling for the development community.

[$] The 6.12 merge window begins

Post Syndicated from corbet original https://lwn.net/Articles/990750/

As of this writing, 6,778 non-merge changesets have been pulled into the
mainline kernel for the 6.12 release — over half of the work that had been
staged in linux-next prior to the opening of the merge window. There has
been a lot of refactoring and cleanup work this time around, but also some
significant changes. Read on for a summary of the first half of the 6.12
merge window.

[$] Considering kernel pass-through interfaces

Post Syndicated from corbet original https://lwn.net/Articles/990802/

The kernel normally sits firmly between user space and the system’s
peripheral devices, and provides a standard interface to those devices. At
times, though, a more direct interface to a device is desired — but such
interfaces can be controversial. At the 2024 Maintainers Summit, the
assembled developers considered a specific case — the proposed fwctl subsystem — as well as the role of such
drivers in general.

The realtime preemption pull request

Post Syndicated from corbet original https://lwn.net/Articles/990985/

[pull request]

On September 19, Thomas Gleixner delivered the pull request for the
realtime preemption enablement patches to Linus Torvalds — in printed form,
wrapped in gold, with a ribbon, as Torvalds had requested. It was a
significant milestone, marking the completion of a project that required
20 years of effort. Congratulations are due to everybody involved.

Torvalds acted on
the pull request the following morning.

[$] The uncertain future of kernel regression tracking

Post Syndicated from corbet original https://lwn.net/Articles/990599/

Tracking of regressions seems like an important task for any project; there
is no other way to ensure that known problems are fixed. At the 2024
Maintainers Summit, though, Thorsten Leemhuis, who has been doing that work
for the kernel, expressed some doubts about whether it is worth continuing.
The result was an energetic session on how regression tracking should be
done better, and how this work should be supported.

[$] Kernel developers at Cauldron

Post Syndicated from corbet original https://lwn.net/Articles/990379/

A Linux system is made up of a large number of interdependent components,
all of which must support each other well. It can thus be surprising that,
it seems, the developers working on those components do not often speak
with each other. In the hope of improving that situation, efforts have
been made in recent years to attract toolchain developers to the
kernel-heavy Linux Plumbers Conference. This year, though, the opposite
happened as well: the 2024
GNU Tools Cauldron hosted a discussion where kernel developers were
invited to discuss their needs.

[$] An update on BPF generation from GCC

Post Syndicated from corbet original https://lwn.net/Articles/990343/

The generation of binary code for the kernel’s BPF virtual machine has been
limited to the Clang compiler since the beginning; even developers who
use GCC to build kernels must use Clang to compile to BPF. Work has
been underway for some years on adding a BPF backend to GCC as well; the
developers involved ran a session at the 2024 GNU Tools Cauldron to
provide an update on that project. It would seem that the BPF backend is
close to being ready for production use.

The 6.11 kernel has been released

Post Syndicated from corbet original https://lwn.net/Articles/990307/

Linus has released the 6.11 kernel.
“I’m once again on the road and not in my normal timezone, but it’s
Sunday afternoon here in Vienna, and 6.11 is out.”
Significant changes in this release include
new io_uring operations for bind() and listen(),
the nested bottom-half locking patches,
the ability to write to busy executable
files,
support for writing block drivers in Rust,
support for atomic write operations in the
block layer,
the dedicated bucket slab allocator,
the vDSO implementation of getrandom(),
and more. See the LWN merge-window summaries
(part 1,
part 2) for more information.

[$] The RCU API, 2024 edition

Post Syndicated from corbet original https://lwn.net/Articles/988638/

Read-copy-update (RCU) is a synchronization mechanism that was added to the
Linux kernel in October 2002. RCU is most frequently used as a replacement
for reader-writer locking, but is also used in a
number of other ways. This article covers recent changes to the RCU
API; it was contributed by Paul McKenney, Boqun Feng, Frederic Weisbecker,
Joel Fernandes, Neeraj Upadhyay, and Uladzislau Rezki.

[$] The trouble with iowait

Post Syndicated from corbet original https://lwn.net/Articles/989272/

CPU scheduling is a challenging job; since it inherently requires making
guesses about what the demands on the system will be in the future, it
remains reliant on heuristics, despite ongoing efforts to remove them.
Some of those heuristics take special note of tasks that are (or appear to
be) waiting for fast I/O operations. There is some unhappiness, though,
with how this factor is used, leading to a couple of patches taking rather
different approaches to improve the situation.

Radicle 1.0 released

Post Syndicated from corbet original https://lwn.net/Articles/989605/

Version 1.0
of the Radicle development platform has been released.

Radicle 1.0 represents the culmination of years of experimentation
and hard work from our team and community, where we set out to
ensure that free and open source software ecosystems can flourish
without having to rely on the whims of Big Tech. We designed
Radicle with a first-principles approach, as a natural extension to
Git, expanding it to work in a collaborative, local-first,
peer-to-peer setting.

LWN looked at Radicle in March.

Security updates for Tuesday

Post Syndicated from corbet original https://lwn.net/Articles/989602/

Security updates have been issued by Debian (cacti), Fedora (aardvark-dns, expat, and firefox), Mageia (ffmpeg, ntfs-3g, and vim), Oracle (emacs, glib2, java-11-openjdk, and qt5-qtbase), Red Hat (emacs, python-setuptools, python3.11, python3.11-setuptools, python3.12-setuptools, python3.9, and python39:3.9), Slackware (netatalk), SUSE (buildah, expat, java-1_8_0-ibm, kanidm, kernel, and postgresql16), and Ubuntu (netty, php7.0, php7.2, tiff, and webkit2gtk).