Tech News Digest - 2025-04-11

📢 No joke file found! 😢

[$] Atomic writes for ext4

Category: Linux
Tags: Linux
Published: Thu, 10 Apr 2025 20:35:18 +0000
TL;DR: Here is a summary of the text in 2 sentences:

Ojaswin Mujoo led a session on supporting atomic writes (untorn I/O) for ext4 filesystem at the 2025 Linux Storage, Filesystem, Memory Management, and BPF Summit. The feature has some upstream kernel support already, but there are still challenges to be addressed, which Mujoo discussed during the session.
Building on the discussion in the two previous sessions on untorn (or atomic) writes, for buffered I/O and for XFS using direct I/O, Ojaswin Mujoo remotely led a session on support for the feature on ext4. That took place in the combined storage and filesystem track at the 2025 Linux Storage, Filesystem, Memory Management, and BPF Summit. Part of the support for the feature is already in the upstream kernel, with more coming. But there are still some challenges that Mujoo wanted to discuss.
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Malcolm: 6 usability improvements in GCC 15

Category: Linux
Tags: General
Published: Thu, 10 Apr 2025 20:29:37 +0000
TL;DR: Here is a summary of the article in 2 sentences:

The GCC 15 compiler has introduced several usability improvements, including better diagnostic information, machine-readable reports using SARIF, and improved error messages for C++ templates and C23 compatibility. Additionally, the compiler now uses color to highlight differences in source code, such as type mismatches, making it easier to identify errors and issues.
Over on the Red Hat Developer site, David Malcolm has an article about improvements in GCC 15, specifically focusing on the diagnostic information that the compiler emits. This includes ASCII art with a "⚠️" warning emoji to display the execution path when it detects a problem (like an infinite loop in one of his examples), better C++ template errors, machine-readable diagnostics using Static Analysis Results Interchange Format (SARIF), better messages regarding C23 compatibility since that is the default C version for GCC 15, and more. Since the changes are focused on messages, there is the inevitable color-scheme update as well:

GCC will use color when emitting its text messages on stderr at a suitably modern terminal, using a few colors that seem to work well in a number of different terminal themes—but the exact rules for choosing which color to use for each aspect of the output have been rather arbitrary.

For GCC 15, I've gone through C and C++'s errors, looking for places where two different things in the source are being contrasted, such as type mismatches. These diagnostics now use color to visually highlight and distinguish the differences.

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[$] Management of volatile CXL devices

Category: Linux
Tags: Linux
Published: Thu, 10 Apr 2025 18:18:22 +0000
TL;DR: Here is a 2-sentence summary:

Compute Express Link (CXL) memory is unique in that it can dynamically come and go at any time, making it challenging to manage. A session was held at the 2025 Linux Storage, Filesystem, Memory-Management, and BPF Summit to discuss the challenges posed by CXL and potential solutions.
Compute Express Link (CXL) memory is not like the ordinary RAM that one might install into a computer; it can come and go at any time and is often not present when the kernel is booting. That complicates the management of this memory. During the memory-management track of the 2025 Linux Storage, Filesystem, Memory-Management, and BPF Summit, Gregory Price ran a session on the challenges posed by CXL and how they might be addressed.
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Eight new stable kernels

Category: Linux
Tags: Linux
Published: Thu, 10 Apr 2025 13:45:32 +0000
TL;DR: Here is a summary of the article in 2 sentences:

Greg Kroah-Hartman has announced the release of eight stable kernels, including versions 6.14.2, 6.13.11, and others. These releases contain a wide range of important kernel fixes throughout the tree, making them suitable for use in production environments.
Greg Kroah-Hartman has announced the release of eight stable kernels: 6.14.2, 6.13.11, 6.12.23, 6.6.87, 6.1.134, 5.15.180, 5.10.236, and 5.4.292. These all contain a large assortment of important kernel fixes throughout the tree.
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[$] Preparing DAMON for future memory-management problems

Category: Linux
Tags: Linux
Published: Thu, 10 Apr 2025 13:39:04 +0000
TL;DR: Here is a summary of the text in 2 sentences:

The Data Access MONitor (DAMON) subsystem provides detailed memory-management statistics and tools for implementing policies based on those statistics. At the Linux Storage, Filesystem, Memory-Management, and BPF Summit in 2025, SeongJae Park led sessions on recent and future DAMON developments, with a focus on evolving the system to facilitate access-aware memory management.
The Data Access MONitor (DAMON) subsystem provides access to detailed memory-management statistics, along with a set of tools for implementing policies based on those statistics. An update on DAMON by its primary author, SeongJae Park, has been a fixture of the Linux Storage, Filesystem, Memory-Management, and BPF Summit for some years. The 2025 Summit was no exception; Park led two sessions on recent and future DAMON developments, and how DAMON might evolve to facilitate a more access-aware memory-management subsystem in the future.
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