Page 3: The hard core

Contents

Processes running on the GPU are reluctant to be aborted. After all, the computing-intensive tasks should not have to be restarted. The new kernel declares war on forced ejection via cgroups. Linux now splits both GPU resources and CPU memory allocated by drivers into cgroups. This allows parallel execution of tasks without influencing each other.

With the predecessor 6.13, Linux introduced the "Lazy Preempt". In preemptive multitasking, it allows context switches to be postponed so that processes or threads are not interrupted unnecessarily. In this way, processing steps can be completed in one go if possible. This "lazy preempt" was only available in Linux 6.13 on computers with CPUs of type x86/x86_64 and RISC-V. Now the kernel newcomer is following suit for the next architecture. With Linux 6.14, the "Lazy Preempt" is also available for systems with PowerPC.

File systems and Copilot

The btrfs file system introduces three new strategies for read balancing in RAID1 (mirroring). "Rotation" keeps all devices of the mirror active and is the default setting. "Latency" intelligently tackles error-prone and unstable block layers. Finally, "devid" allows manual control. Depending on the application scenario, the appropriate strategy should help to better distribute read accesses across the devices in RAID1.

XFS enhances its real-time device. This special mode enables consistent, predictable latencies for file system operations. The new Linux kernel adds "reverse mapping". It allows blocks on the storage device to be mapped to the file from which the storage blocks are used. Normally, the associated blocks can only be identified from the file. Another new feature is "reflink". This allows files in XFS to share memory blocks. This avoids redundancy and saves storage space.

Microsoft has added a new key to PC keyboards. The Copilot key is used to access the AI assistant of the software giant from Redmond. Until now, Linux ignored this key. Now Linux also recognizes when this key is pressed. However, this does not create a permanent link to the Copilot assistant.

Summarized

With just over 11,000 changesets with new functionality, Linux 6.14 lags modestly behind a long line of its ancestors. Only Linux kernels of versions 4.x were smaller in this respect. Despite this "meager" quantity, the new version brings a lot of quality. The speed increases in Windows games are remarkable. The ingenious trick of uncached buffered I/O closes a gap between the otherwise opposing I/O strategies. This alone makes the next incarnation of the kernel an innovation boost.

The Linux kernel 6.14 is available for download as usual at kernel.org. All new features and changes are summarized in the changelog. A structured overview of the changes compared to the predecessor 6.13 can also be found in the git repository.

(wpl)