diff --git a/xtoskrnl/includes/po.h b/xtoskrnl/includes/po.h
index 1505a64..2f9118e 100644
--- a/xtoskrnl/includes/po.h
+++ b/xtoskrnl/includes/po.h
@@ -21,4 +21,15 @@ XTFASTCALL
 VOID
 PopIdle0Function(IN PPROCESSOR_POWER_STATE PowerState);
 
+XTAPI
+VOID
+PopPerfIdle(PPROCESSOR_POWER_STATE PowerState);
+
+XTAPI
+VOID
+PopPerfIdleDpc(IN PKDPC Dpc,
+               IN PVOID DeferredContext,
+               IN PVOID SystemArgument1,
+               IN PVOID SystemArgument2);
+
 #endif /* __XTOSKRNL_PO_H */
diff --git a/xtoskrnl/po/idle.c b/xtoskrnl/po/idle.c
index 4acc665..cb4d1b8 100644
--- a/xtoskrnl/po/idle.c
+++ b/xtoskrnl/po/idle.c
@@ -23,12 +23,17 @@ XTAPI
 VOID
 PoInitializeProcessorControlBlock(IN OUT PKPROCESSOR_CONTROL_BLOCK Prcb)
 {
+    /* Zero memory */
     RtlZeroMemory(&Prcb->PowerState, sizeof(Prcb->PowerState));
 
+    /* Initialize default power state */
     Prcb->PowerState.Idle0TimeLimit = 0xFFFFFFFF;
     Prcb->PowerState.CurrentThrottle = 100;
     Prcb->PowerState.IdleFunction = PopIdle0Function;
 
+    /* Initialize DPC and Timer */
+    KeInitializeDpc(&Prcb->PowerState.PerfDpc, PopPerfIdleDpc, Prcb);
+    KeSetTargetProcessorDpc(&Prcb->PowerState.PerfDpc, Prcb->Number);
     KeInitializeTimerEx(&Prcb->PowerState.PerfTimer, SynchronizationTimer);
 }
 
@@ -48,3 +53,49 @@ PopIdle0Function(IN PPROCESSOR_POWER_STATE PowerState)
 {
     UNIMPLEMENTED;
 }
+
+/**
+ * Switches CPU between different performance levels.
+ *
+ * @param PowerState
+ *        Supplies a pointer to the structure containing IDLE processor power state.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since NT 5.1
+ */
+XTAPI
+VOID
+PopPerfIdle(PPROCESSOR_POWER_STATE PowerState)
+{
+    UNIMPLEMENTED;
+}
+
+/**
+ * Checks if CPU is running at the maximum (performance) frequency.
+ *
+ * @param Dpc
+ *        Supplies a pointer to the DPC object.
+ *
+ * @param DeferredContext
+ *        Supplies a pointer to memory area containing current CPU's PRCB.
+ *
+ * @param SystemArgument1
+ *        Supplies a pointer to an unused system argument.
+ *
+ * @param SystemArgument2
+ *        Supplies a pointer to an unused system argument.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since NT 5.1
+ */
+XTAPI
+VOID
+PopPerfIdleDpc(IN PKDPC Dpc,
+               IN PVOID DeferredContext,
+               IN PVOID SystemArgument1,
+               IN PVOID SystemArgument2)
+{
+    UNIMPLEMENTED;
+}