illumos gate

Some AMD CPUs have a feature called "Core Performance Boost". The CPUs can boost the frequency of one or more core if other cores are idle. This is similar to the Intels "Turbo Boost" feature, it even uses the same MSRs to report the boosted frequencies, although AMD systems do not report a special boosted Pstate to the OS.

The code to collect information about boosting already exists in the Speedstep driver. This needs to be moved to a separate file, and code to use it needs to be added to the PowerNow driver. Also, powertop needs to be modified to report the correct frequency despite the lack of the boosted Pstate.