Why not port Linux kernel to Common Lisp?

Conventional wisdom states that OS kernels must be written in C in order to achieve the necessary levels of performance. This has been the justification for not using more expressive high level languages.

However, for a few years now implementations of Common Lisp such as SBCL have proven to be just as performant as C. What then are the arguments against redoing the kernel in a powerfully expressive language, namely Common Lisp?

I don't think anyone (at least anyone who knows what they are talking about) could argue against the fact that the benefits in transparency and readability would be tremendous, not to mention all the things that can't be done in C that can be done in Lisp, but there may be implementation details that would make this a bad idea.

>>32
Still the main problems are dynamic typing and garbage collection, which could be unpredictable, but using manual memory management and limiting precision to fixnums would just invite bugs. I.e. one would want to use full blown Lisp all the way down, just after bootstrap.