The debate surrounding Linux kernel contributions continues to rage in the open source community, particularly when it comes to emerging architectures like RISC-V. In 2025, Linux icon Linus Torvalds publicly criticized a code contribution from a Google engineer, calling the changes “garbage” and claiming that the code only worsened the software ecosystem. This intervention comes at a time when code quality and rigorous submission management are more crucial than ever for Linux kernel 6.17 and beyond. At the same time, Torvalds warned another developer for late submissions, illustrating his vigilance and strict adherence to community contribution guidelines. Linus Torvalds and the Rigor of Integrating Contributions into the Linux Kernel
Linus Torvalds has always been very strict about the quality and timing of contributions proposed for inclusion in the Linux kernel, the heart of most GNU/Linux distributions. For more than three decades, he has imposed high standards to maintain the stability and performance of the Linux kernel, an open source project that unites thousands of software engineers around the world.
In the spring of 2025, this severity was highlighted during the code review of a contribution related to the RISC-V architecture, submitted by a Google engineer, Palmer Dabbelt. This submission was rejected by Torvalds, who called the patch “garbage” for its inappropriate content. This scathing comment underscores the importance of taking care with each contribution, not only to preserve the quality of the kernel, but also to facilitate the timely integration of improvements. The Linux kernel, in its ongoing evolution, particularly towards version 6.17, requires rigor that is all the more crucial as architectures like RISC-V gain in importance in the hardware and software landscape.
This case highlights the challenges associated with managing open source contributions: beyond simply submitting code, it is imperative to respect quality standards, rigorously document and validate proposals, and adhere to a strict schedule. Torvalds emphasizes that late, or even poorly prepared, contributions slow down maintainers’ work and can degrade the overall quality of the Linux kernel. With this in mind, he issued a stern warning to Palmer Dabbelt: no new late submissions, and no more code “outside the RISC-V zone.”
Respect submission deadlines within kernel merge windows
- Rigorous code quality to avoid regressions
- Compliance with Linux-specific architectures and standards
- Importance of collaborative work in the community
- Accountability and transparency in code reviews
- Linus Torvalds criticizes Google’s RISC-V strategy, highlighting technical and compatibility choices. Discover the challenges for the open source ecosystem.
Linus Torvalds’s criticism is not simply a negative remark. It is based on a precise technical analysis of the proposed contribution to Linux kernel 6.17, targeting changes intended to improve the integration of RISC-V, an open source architecture renowned for its modularity and disruptive potential.
According to Torvalds, this contribution contains a series of non-RISC-V-specific additions that pollute the kernel’s generic header files, which is contrary to good modular software architecture. In a systems engineering approach, generic files must be kept clear and clean to ensure good architectural isolation and minimize side effects. Introducing excessive or poorly targeted code in these areas can lead to conflicts, errors, and unnecessary complexity for future maintenance.
Torvalds is clear: this type of code should never be submitted, especially not at the end of an already critical merge window. The “garbage” metaphor reflects a deep dissatisfaction with the quality and technical relevance of the modifications.
In the open source review process, these remarks emphasize the need for thorough upstream peer validation. They also demonstrate the difficulty of integrating a recent architecture like RISC-V into an ecosystem as complex as Linux, where every line of code impacts performance, security, and overall maintainability. The case of this contribution also serves as a reminder that software engineers must imperatively understand the systemic consequences of their modifications, especially in a context as sensitive as the Linux kernel.
Dangers of Poor Isolation of Hardware Architectures in Generic Files
- Negative Impact on Linux Kernel Maintainability
- Importance of adhering to modularity practices
- Risks associated with late submissions in the development cycle
- Requirement for serious collaborative work in code review
- Linus Torvalds criticizes Google’s RISC-V initiative, reigniting the debate on open source architecture and the ecosystem. Discover the key issues.
Another central aspect raised by this controversy is the rigorous management of contributions in major open source projects like Linux. The kernel development model imposes strict windows, called merge windows, during which developers can submit their patches. Any late submission is both difficult to manage and a source of potential conflicts.
In this case, the late submission of code by a member of the Android team at Google provoked a firm reaction from Torvalds. The reminder—”you’re on notice”—symbolizes this vigilance: poor-quality or late contributions are immediately identified and punished. This clear message underscores the importance of adopting strict discipline to preserve the integrity of the Linux kernel.
This approach is essential not only for technical quality, but also for good collaborative management. The Linux community, a truly distributed ecosystem, relies on close coordination between maintainers, developers, partner companies, and independent contributors. Adherence to deadlines and pre-established rules is a cornerstone for avoiding technical and temporal disagreements that could delay releases and compromise the robustness of the kernel.
Finally, this rigor in contribution management ensures transparency, traceability, and efficiency in development cycles. With this in mind, several Linux distributions and projects have already adopted innovative tools and methodologies to improve code reviews and automate certain checks, which should facilitate the work of maintainers in 2025 and beyond.
Importance of merge windows in planning
- Risks associated with late submissions
- Essential coordination between maintainers and contributors
- Modern tools for automating code reviews
- Maintaining the robustness and security of the Linux kernel
- Discover why Linus Torvalds criticizes Google’s approach to RISC-V: fragmentation, ABI, and challenges for Linux and the open source ecosystem.
The RISC-V architecture represents a free and open alternative to legacy architectures such as x86 and ARM. Its simplicity, modular design, and open license have made it a prime target for many open source projects, including Linux. However, its integration into the Linux kernel faces complex challenges that combine technical, organizational, and community aspects.
On the technical level, RISC-V requires consideration of specific elements such as register management, modular extensions, and compatibility with various hardware platforms. This complexity requires rigorous and collaborative groundwork to avoid reintroducing known errors from other architectures, particularly in terms of performance and security.
From a community perspective, the rise of RISC-V increases the pressure on contribution management. Software engineers at companies like Google must adapt to a strict code review culture focused on quality over quantity. Linus Torvalds’s recent warning illustrates the challenge of maintaining a balance between hardware innovation and software mastery.
Finally, the success of an architecture in the Linux world depends not only on its intrinsic qualities, but also on collective acceptance, support from distributions and maintainers, and the speed of integration into the development chain. These factors determine the pace and quality of its adoption, as can be seen in the initiatives surrounding the 6.17 release and the addition of Rust to the kernel. Technical Specificities of RISC-V to be Integrated
Comparison with ARM and x86 in the Linux Kernel
- Essential Collaboration between Companies and the Open Source Community
- Importance of Standards to Avoid Historical Mistakes
- Role of Maintainers in Validating Contributions
- Impact of Torvalds’ Criticisms on the Community and Reflections on Managing Linux Contributions
- Linus Torvalds’s public statements, even brutal ones, are rarely without technical foundation and aim to protect the integrity of the Linux kernel. Nevertheless, they also spark debates within the open source community. These exchanges highlight the potential tensions between technical requirements, development schedules, and human respect for contributors.
Some users see Torvalds’ outspokenness as a powerful driving force for ensuring technical excellence. Others lament an overly aggressive stance that could discourage software engineers, particularly those from large companies like Google, from investing confidently in Linux. This duality reflects the complexities inherent in any collaborative open source management where mutual respect and rigor must coexist.
Furthermore, this affair raises the question of training and support for contributors to better understand the Linux philosophy and its requirements. The evolution of the kernel to versions like 6.17, incorporating new technologies and languages (notably increased support for Rust), requires the community to continually adapt to these quality and timing standards. Importance of dialogue and education in code reviews
Challenges of integrating large companies like Google into Linux
Role of reviewers in maintaining a robust and secure kernel
- Need for tools and processes to better manage contributions
- Balance between technical requirements and respect for contributors