Lets cross that bridge when we come to it.
Frankly, if somebody cares about power or performance,
they shouldn't be running powernowd/cpufreqd, and so
they should be blissfully ignorant and satisfied with the
default, which is 'balanced'.
We really do need a central place for userspace to communicate
power/performance bias policy to the kernel -- and for kernel drivers
of all types to pick up that policy. I think that ideally
the sysfs interface should be generic, and that on systems with
this MSR, the MSR gets plugged into updates to that generic
I think that this driver exposing the MSR to cpufreq is useful,
but perhaps it is just a stepping stone to the generic I/F
that we really should implement...
Intel Open Source Technology Center