Rust DMA dispute in the Linux kernel: developer backs off somewhat
After Linus Torvalds overruled Christoph Hellwig's veto on Rust code in the DMA mapping area, the latter is now relinquishing two of six supervisor positions.
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The disputes over the use of Linux's DMA mapping codes have another consequence: Christoph Hellwig, who started the whole thing with a publicly announced blockade, is stepping down as the maintainer of Linux's DMA mapping code. Hellwig is also giving up two other tasks, but is apparently continuing to work diligently on the development of the kernel.
The whole thing happened around three weeks after Hellwig publicly announced his disapproval of the Rust DNA interfaces – and around four days after Torvalds made it very clear that he would ignore Hellwig's resistance in case of doubt: Maintainers of parts of the kernel who do not contribute to the development of Rust for Linux and Rust code based on it would simply have no say in how other parts of the kernel use their C code, according to the Linux founder and lead developer.
Kernel developer withdraws from parts of development
Hellwig has not only handed over the maintenance of the DMA mapping code, but also that of Configfs; in addition, he is withdrawing as an officially registered reviewer of Vmalloc changes because, according to his statement, he has been less active there recently and wants to reduce his workload. Hellwig will retain four other maintainer positions, including those as maintainer of the NVMe and NVMe target driver. Since his resignations announced on Monday, he has also continued to be involved in Linux development to the usual extent, according to a very rough estimate.
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Hellwig is a long-standing and extremely active developer who has contributed countless important improvements to Linux and has repeatedly helped other programmers to integrate new features. However, like Torvalds, he has never shied away from clear words or confrontations – and even sued VMWare a few years ago for a GPL violation. With his blockade of the Rust DMA code and the resulting debates, he has now caused a huge stir, as two well-known developers have withdrawn from Linux development as a result: The Rust DMA controversy in the Linux kernel – an attempt at analysis.
Much ado about a difference of opinion
To briefly categorize the whole thing once again from the perspective of the author, who has been intensively observing Linux development for over two decades and is currently involved in it himself:
Hellwig's public blockade attitude, including the withdrawal that has now become public, was a maneuver that is not uncommon in Linux development – and resembles differences of opinion or disputes that happen behind closed doors in many companies every day. However, because Linux development happens via public lists, everyone can watch. This has provided the media with plenty of fodder (and revenue via advertising) – and also given experts and snackers plenty to discuss. Ultimately, this has caused far more unrest in the scene than the whole thing is actually worth. The bigger problems are actually those surrounding the Rust DMA drama that led to the departure of two developers who were only partially involved. These issues, such as high hurdles for contributing code or politically clumsy statements from central, unapologetic developers, were already smouldering before – and will probably continue to do so, as improvements in these areas are making little progress.
(emw)
