VOID
PopPerfIdle(
  IN  PPROCESSOR_POWER_STATE  PState
  );

Routine Description:

    This routine is responsible for promoting or demoting the processor
    between various performance levels. It can *only* be called from within
    the context of the idle handler and the appropriate target processor

Arguments:

    PState  - power state of the processor that is idle

Return Value:

    None