Final power management fixes for 3.15 - Taking non-idle time into account when calculating core busy time was a mistake and led to a performance regression. Since the problem it was supposed to address is now taken care of in a different way, we don't need to do it any more, so drop the non-idle time tracking from intel_pstate. Dirk Brandewie. - Changing to fixed point math throughout the busy calculation introduced rounding errors that adversely affect the accuracy of intel_pstate's computations. Fix from Dirk Brandewie. - The PID controller algorithm used by intel_pstate assumes that the time interval between two adjacent samples will always be the same which is not the case for deferable timers (used by intel_pstate) when the system is idle. This leads to inaccurate predictions and artificially increases convergence times for the minimum P-state. Fix from Dirk Brandewie. - intel_pstate carries out computations using 32-bit variables that may overflow for large enough values of APERF/MPERF. Switch to using 64-bit variables for computations, from Doug Smythies. /