diff --git a/firmware/config/stm32f4ems/chconf.h b/firmware/config/stm32f4ems/chconf.h
index 533c440fb1..343e747798 100644
--- a/firmware/config/stm32f4ems/chconf.h
+++ b/firmware/config/stm32f4ems/chconf.h
@@ -35,10 +35,28 @@
 #define CHPRINTF_USE_FLOAT          	TRUE
 
 #if !defined(EFI_CLOCK_LOCKS) || defined(__DOXYGEN__)
+// looks like this value could not be defined in efifeatures.h - please define either externally or just change the value here
  #define EFI_CLOCK_LOCKS FALSE
 #endif /* EFI_CLOCK_LOCKS */
 
 
+#ifdef __cplusplus
+extern "C"
+{
+#endif /* __cplusplus */
+ #ifndef __ASSEMBLER__
+  #if EFI_CLOCK_LOCKS
+    void irqEnterHook(void);
+    void irqExitHook(void);
+  #else /* EFI_CLOCK_LOCKS */
+    #define irqEnterHook() {}
+    #define irqExitHook() {}
+  #endif /*EFI_CLOCK_LOCKS */
+ #endif /* __ASSEMBLER__ */
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
 #if EFI_CLOCK_LOCKS
 #ifdef __cplusplus
 extern "C"
@@ -511,6 +529,7 @@ extern "C"
  */
 #define CH_CFG_IRQ_PROLOGUE_HOOK() {                                        \
   /* IRQ prologue code here.*/                                              \
+  irqEnterHook();                                                           \
 }
 
 /**
@@ -518,6 +537,7 @@ extern "C"
  */
 #define CH_CFG_IRQ_EPILOGUE_HOOK() {                                        \
   /* IRQ epilogue code here.*/                                              \
+  irqExitHook();                                                            \
 }
 
 /**
diff --git a/firmware/controllers/engine_controller.cpp b/firmware/controllers/engine_controller.cpp
index a14bb871ad..cd1b7a7670 100644
--- a/firmware/controllers/engine_controller.cpp
+++ b/firmware/controllers/engine_controller.cpp
@@ -246,6 +246,43 @@ static void resetAccel(void) {
 	engine->wallFuel.reset();
 }
 
+
+#if EFI_CLOCK_LOCKS
+static int previousSecond;
+
+typedef FLStack<int, 16> irq_enter_timestamps_t;
+
+static irq_enter_timestamps_t irqEnterTimestamps;
+
+void irqEnterHook(void) {
+	irqEnterTimestamps.push(GET_TIMESTAMP());
+}
+
+static int currentIrqDurationAccumulator = 0;
+static int currentIrqCounter = 0;
+/**
+ * See also maxLockedDuration
+ */
+int perSecondIrqDuration = 0;
+int perSecondIrqCounter = 0;
+void irqExitHook(void) {
+	int enterTime = irqEnterTimestamps.pop();
+	currentIrqDurationAccumulator += (GET_TIMESTAMP() - enterTime);
+	currentIrqCounter++;
+}
+#endif /* EFI_CLOCK_LOCKS */
+
+static void invokePerSecond(void) {
+#if EFI_CLOCK_LOCKS
+	// this data transfer is not atomic but should be totally good enough
+	perSecondIrqDuration = currentIrqDurationAccumulator;
+	perSecondIrqCounter = currentIrqCounter;
+	currentIrqDurationAccumulator = currentIrqCounter = 0;
+#endif /* EFI_CLOCK_LOCKS */
+
+}
+
+
 static void periodicSlowCallback(Engine *engine) {
 	efiAssertVoid(CUSTOM_ERR_6661, getRemainingStack(chThdGetSelfX()) > 64, "lowStckOnEv");
 #if EFI_PROD_CODE
@@ -253,11 +290,16 @@ static void periodicSlowCallback(Engine *engine) {
 	 * We need to push current value into the 64 bit counter often enough so that we do not miss an overflow
 	 */
 	bool alreadyLocked = lockAnyContext();
-	updateAndSet(&halTime.state, port_rt_get_counter_value());
+	updateAndSet(&halTime.state, GET_TIMESTAMP());
 	if (!alreadyLocked) {
 		unlockAnyContext();
 	}
-#endif
+	int timeSeconds = getTimeNowSeconds();
+	if (previousSecond != timeSeconds) {
+		previousSecond = timeSeconds;
+		invokePerSecond();
+	}
+#endif /* EFI_PROD_CODE */
 
 	/**
 	 * Update engine RPM state if needed (check timeouts).
@@ -265,9 +307,9 @@ static void periodicSlowCallback(Engine *engine) {
 	engine->rpmCalculator.checkIfSpinning(PASS_ENGINE_PARAMETER_SIGNATURE);
 
 	if (engine->rpmCalculator.isStopped(PASS_ENGINE_PARAMETER_SIGNATURE)) {
-#if (EFI_PROD_CODE && EFI_ENGINE_CONTROL && EFI_INTERNAL_FLASH) || defined(__DOXYGEN__)
+#if EFI_INTERNAL_FLASH || defined(__DOXYGEN__)
 		writeToFlashIfPending();
-#endif
+#endif /* EFI_INTERNAL_FLASH */
 		resetAccel();
 	} else {
 		updatePrimeInjectionPulseState(PASS_ENGINE_PARAMETER_SIGNATURE);
@@ -282,7 +324,7 @@ static void periodicSlowCallback(Engine *engine) {
 	engine->updateSlowSensors();
 	engine->checkShutdown();
 
-#if (EFI_PROD_CODE && EFI_FSIO) || defined(__DOXYGEN__)
+#if EFI_FSIO || defined(__DOXYGEN__)
 	runFsio(PASS_ENGINE_PARAMETER_SIGNATURE);
 #endif /* EFI_PROD_CODE && EFI_FSIO */
 
@@ -736,5 +778,5 @@ int getRusEfiVersion(void) {
 	if (initBootloader() != 0)
 		return 123;
 #endif /* EFI_BOOTLOADER_INCLUDE_CODE */
-	return 20181209;
+	return 20181223;
 }
diff --git a/firmware/controllers/trigger/trigger_central.cpp b/firmware/controllers/trigger/trigger_central.cpp
index 0e97e53713..bf3318e479 100644
--- a/firmware/controllers/trigger/trigger_central.cpp
+++ b/firmware/controllers/trigger/trigger_central.cpp
@@ -505,6 +505,9 @@ extern uint32_t hwSetTimerDuration;
 extern uint32_t maxLockedDuration;
 extern uint32_t maxEventCallbackDuration;
 
+extern int perSecondIrqDuration;
+extern int perSecondIrqCounter;
+
 #if (EFI_PROD_CODE) || defined(__DOXYGEN__)
 extern uint32_t maxPrecisionCallbackDuration;
 #endif /* EFI_PROD_CODE  */
@@ -622,6 +625,10 @@ void triggerInfo(void) {
 
 #if EFI_CLOCK_LOCKS || defined(__DOXYGEN__)
 	scheduleMsg(logger, "maxLockedDuration=%d / maxTriggerReentraint=%d", maxLockedDuration, maxTriggerReentraint);
+
+	scheduleMsg(logger, "perSecondIrqDuration=%d ticks / perSecondIrqCounter=%d", perSecondIrqDuration, perSecondIrqCounter);
+	scheduleMsg(logger, "IRQ CPU utilization %f%%", perSecondIrqDuration / 168000000.0 * 100);
+
 #endif /* EFI_CLOCK_LOCKS */
 
 	scheduleMsg(logger, "maxEventCallbackDuration=%d", maxEventCallbackDuration);