A mixed-language codebase will always be more complex than a single language one. So it's not just a matter of Rust integrating well-enough with the rest of the

A mixed-language codebase will always be more complex than a single language one. So it's not just a matter of Rust integrating well-enough with the rest of the kernel, but it has to offer enough improvement for the cost to be worthwhile. So to evaluate whether it's worth introducing rust, you'd ideally want to find a self-contained part of the kernel that is responsible for many CVEs and you'd want to show a substantial reduction of CVEs with the rewrite of just that component. Not impossible, but also not so easy.