Linux Kernel 2025: New Schedulers, Rust, & Torvalds’ Insights
▼ Summary
– The Linux kernel saw significant integration of Rust code in 2025, with its use now considered a permanent success and actively promoted for new development.
– Linus Torvalds made several decisive leadership moves, including rejecting RISC-V updates, criticizing Rust formatting, and becoming stricter about “useless” link tags in Git commits.
– The Bcachefs file-system was removed from the mainline kernel in 2025 after being marked externally maintained, casting uncertainty on its future inclusion.
– Major development highlights included new drivers like NTSYNC for gaming performance, the open-sourcing of XTX Markets’ TernFS, and proposals for a multi-kernel architecture.
– Community and maintainer changes occurred, such as the lead wireless driver maintainer stepping down and debates over Rust policy leading to a DMA mapping maintainer’s resignation.
As 2025 concludes, the Linux kernel development landscape has been marked by significant technical evolution and vibrant community debate. The year saw a substantial increase in Rust code integration, a topic that generated considerable discussion among maintainers. Linus Torvalds remained a central figure, making decisive calls on everything from architecture updates to code formatting, while the community navigated the removal of the Bcachefs file-system and welcomed innovations in scheduling and system design.
One of the more intriguing stories emerged from the Linux Plumbers Conference, where it was revealed that Meta is successfully utilizing a scheduler originally crafted for Valve’s Steam Deck on its massive hyperscale servers. This demonstrates the scheduler’s remarkable adaptability across vastly different hardware platforms, from handheld gaming devices to enterprise data centers.
Torvalds also made his stance clear on development practices, expressing frustration with “useless” link tags in Git commit messages and vowing to enforce stricter standards. In build system news, patches in the kbuild-next tree propose enabling the `-fms-extensions` compiler argument globally, potentially allowing GCC and LLang to use Microsoft C Extensions for kernel compilation, pending final approval for the Linux 6.19 merge window.
The file-system arena experienced notable shifts. Following its designation as “externally maintained” in Linux 6.17, the Bcachefs code was completely removed from the mainline kernel in the 6.18 release. In a separate but significant milestone, the first CVE vulnerability was assigned to a component written in Rust within the kernel, highlighting the growing footprint and scrutiny of this newer code.
Maintainer transitions also made headlines, with the sole maintainer of Linux wireless drivers stepping down without an immediate successor, following a similar departure by a DRM driver developer. Architecturally, Torvalds rejected the RISC-V updates for Linux 6.17, criticizing the quality and timing of the submission, delaying its integration until a later cycle.
Graphics driver updates for Linux 6.15 were merged, but not without criticism from Torvalds, who took issue with new “hdrtest” code being included in full builds. On the proposal front, an RFC was posted for a multi-kernel architecture, envisioning multiple independent kernel instances coexisting on a single machine, which could enable specialized use-cases like running real-time kernels on dedicated cores.
In the financial technology sector, XTX Markets open-sourced its TernFS file-system, developed to manage over 650 petabytes of storage for algorithmic trading after outgrowing NFS. Meanwhile, the debate around kernel programming languages intensified. While some maintainers voiced objections, Linus Torvalds and Greg Kroah-Hartman have been strong proponents of Rust, with Kroah-Hartman encouraging new drivers to be written in Rust over C. Lead developer Miguel Ojeda declared the “Rust experiment” a success, stating “Rust is here to stay” in the kernel.
Gaming on Linux received a potential boost with the NTSYNC driver, aimed at enhancing Wine/Proton performance by better implementing Windows NT synchronization primitives, slated for the Linux 6.14 kernel. For NVIDIA graphics, the initial code for the Rust-based NOVA driver, intended as a successor to Nouveau for modern GPUs with GSP firmware, was submitted for the Linux 6.15 window.
Security efforts saw progress as Google’s Address Space Isolation (ASI) work, designed to mitigate CPU speculative execution attacks, reduced its I/O performance overhead from an initial 70% hit down to a more manageable 13%. In user-space communication, Linux 6.15 will introduce a standardized method for notifying users of hung GPUs, initially for AMD and Intel drivers.
The ongoing Rust discussions prompted Torvalds to intervene on code formatting, criticizing “crazy Rust format checking” that condensed multi-line imports. Subsequent fixes and updated guidelines were quickly merged to address his concerns. In a related development, Christoph Hellwig, a critic of Rust in the kernel and maintainer of DMA mapping helpers, stepped down from his maintainer role following the debates.
Finally, new approaches to system efficiency emerged. The Swap Table concept was born from discussions, promising lower memory use and higher performance for swap operations. Bytedance engineers proposed Run Process As Library (RPAL) for faster inter-process communication, showing promising initial benchmarks. As the year wraps up, the kernel community continues its steadfast march, setting the stage for further innovation in 2026.
(Source: NewsAPI Tech Headlines)
