<a href="http:&#x2F;&#x2F;research.google.com&#x2F;pubs&#x2F;archive&#x2F;34913.pdf" rel="nofollow">http:&#x2F;&#x2F;research.google.com&#x2F;pubs&#x2F;archive&#x2F;34913.pdf</a> section 4 discusses performance: &quot;The worst case performance overhead is [the SPEC2000 benchmark named] crafty at about 12%, with other benchmarks averaging about 5% overall.&quot; For some applications, there is no slowdown or even a minor speedup because of weird caching behavior and alignment.<p>I haven&#x27;t seen this used for a general-purpose OS distro (I suppose you&#x27;d use it for running a VM-like thing as an unprivileged user, without access to any hardware features) but I agree it would be cool.