Committing to Rust for kernel code

I'm speaking about implications of a fast-moving toolchain. When a toolchain moves fast the code can diverge quickly, to reach a point where backports are extremely complicated because sometimes they rely on a lot of new infrastructure. We've seen issues in the past where backporting fixes was a real mess. I'm thinking about the IRET bug for example, which required significant adaptations to the old code, backporting some infrastructure stuff while trying hard not to break anything. We could estimate ourselves lucky that the asm language did not evolve over all these years and that the infrastructure parts could be backported without other particular dependencies. But when you don't have all the underlying infrastructure available in older releases because it came with newer versions of the language, it's not the same game anymore. I was definitely not speaking about developers being lazy, just difficulties caused by dependencies on an updated version of a toolchain. That's not something we're used to with gcc, in the worst case it just requires less clean code.