I believe OpenBSD does most of these things. The primary problem is that security is a tradeoff -- for instance OpenBSD completely disabled hyperthreading when

I believe OpenBSD does most of these things. The primary problem is that security is a tradeoff -- for instance OpenBSD completely disabled hyperthreading when it was discovered to be fundamentally insecure. That was a 50% performance hit right off the bat -- not everyone can afford to make such a tradeoff.