The Linux kernel is already very complex, and I expect that replacing much or all of it with Rust code will be good for making it more tractable to understand. Because you can represent complex states with more sophisticated types than in C, if nothing else.
I've been working on Rust bindings for a C SDK recently, and the Rust wrapper code was far more complex than the C code it wrapped. I ended up ceding and getting reasonable wrappers by limiting how it can be used, instead of moddeling the C API's full capabilities. There are certainly sound, reasonable models of memory ownership that are difficult or impossible to express with Rust's ownership model.
Sure, a different model that was easy to model would have been picked if we were initially using Rust, but we were not, and the existing model in C is what we need to wrap. Also, a more Rust-friendly model would have incured higher memory costs.
By most accounts the Rust4Linux project has made the kernel less complex by forcing some technical debt to be addressed and bad APIs to be improved.
The Linux kernel is already very complex, and I expect that replacing much or all of it with Rust code will be good for making it more tractable to understand. Because you can represent complex states with more sophisticated types than in C, if nothing else.
Complexity of Rust is just codifying existing complexity.
I've been working on Rust bindings for a C SDK recently, and the Rust wrapper code was far more complex than the C code it wrapped. I ended up ceding and getting reasonable wrappers by limiting how it can be used, instead of moddeling the C API's full capabilities. There are certainly sound, reasonable models of memory ownership that are difficult or impossible to express with Rust's ownership model.
Sure, a different model that was easy to model would have been picked if we were initially using Rust, but we were not, and the existing model in C is what we need to wrap. Also, a more Rust-friendly model would have incured higher memory costs.
There’s one already — they seem to be doing decently well.
https://www.redox-os.org/