diff --git a/src/system/kernel/arch/x86/arch_timer.cpp b/src/system/kernel/arch/x86/arch_timer.cpp
index 2248afa4fd..b533f5738f 100644
--- a/src/system/kernel/arch/x86/arch_timer.cpp
+++ b/src/system/kernel/arch/x86/arch_timer.cpp
@@ -27,11 +27,12 @@
 
 //#define TRACE_TIMER
 #ifdef TRACE_TIMER
-#	define TRACE(x) dprintf x
+#	define TRACE(x...) dprintf("arch_timer: " x)
 #else
-#	define TRACE(x) ;
+#	define TRACE(x...) ;
 #endif
 
+
 extern timer_info gPITTimer;
 extern timer_info gAPICTimer;
 extern timer_info gHPETTimer;
@@ -48,7 +49,7 @@ static timer_info *sTimer = NULL;
 void
 arch_timer_set_hardware_timer(bigtime_t timeout)
 {
-	TRACE(("arch_timer_set_hardware_timer: timeout %lld\n", timeout));
+	TRACE("arch_timer_set_hardware_timer: timeout %" B_PRIdBIGTIME "\n", timeout);
 	sTimer->set_hardware_timer(timeout);
 }
 
@@ -56,7 +57,7 @@ arch_timer_set_hardware_timer(bigtime_t timeout)
 void
 arch_timer_clear_hardware_timer(void)
 {
-	TRACE(("arch_timer_clear_hardware_timer\n"));
+	TRACE("arch_timer_clear_hardware_timer\n");
 	sTimer->clear_hardware_timer();
 }
 
@@ -65,10 +66,10 @@ static void
 sort_timers(timer_info *timers[], int numTimers)
 {
 	timer_info *tempPtr;
-	int max = 0;	
+	int max = 0;
 	int i = 0;
 	int j = 0;
-	
+
 	for (i = 0; i < numTimers - 1; i++) {
 		max = i;
 		for (j = i + 1; j < numTimers; j++) {
@@ -78,10 +79,10 @@ sort_timers(timer_info *timers[], int numTimers)
 		if (max != i) {
 			tempPtr = timers[max];
 			timers[max] = timers[i];
-			timers[i] = tempPtr;		
+			timers[i] = tempPtr;
 		}
 	}
-	
+
 #if 0
 	for (i = 0; i < numTimers; i++)
 		dprintf(" %s: priority %d\n", timers[i]->name, timers[i]->get_priority());
@@ -97,7 +98,7 @@ arch_init_timer(kernel_args *args)
 
 	timer_info *timer = NULL;
 	cpu_status state = disable_interrupts();
-	
+
 	for (int i = 0; (timer = sTimers[i]) != NULL; i++) {
 		if (timer->init(args) == B_OK)
 			break;
diff --git a/src/system/kernel/arch/x86/timers/x86_apic.cpp b/src/system/kernel/arch/x86/timers/x86_apic.cpp
index 568cd65244..c8c2351acb 100644
--- a/src/system/kernel/arch/x86/timers/x86_apic.cpp
+++ b/src/system/kernel/arch/x86/timers/x86_apic.cpp
@@ -18,6 +18,14 @@
 #include "apic_timer.h"
 
 
+//#define TRACE_APIC
+#ifdef TRACE_APIC
+#	define TRACE(x...) dprintf("apic: " x)
+#else
+#	define TRACE(x...) ;
+#endif
+
+
 /* Method Prototypes */
 static int apic_timer_get_priority();
 static status_t apic_timer_set_hardware_timer(bigtime_t relativeTimeout);
@@ -70,8 +78,9 @@ apic_timer_set_hardware_timer(bigtime_t relativeTimeout)
 	config = apic_lvt_timer() & ~APIC_LVT_MASKED; // unmask the timer
 	apic_set_lvt_timer(config);
 
-	//TRACE_TIMER(("arch_smp_set_apic_timer: config 0x%lx, timeout %Ld, tics/sec %lu, tics %lu\n",
-	//	config, relativeTimeout, sApicTicsPerSec, ticks));
+	TRACE("arch_smp_set_apic_timer: config 0x%" B_PRIx32 ", timeout %" B_PRIdBIGTIME
+		", tics/sec %" B_PRIu32 ", tics %" B_PRId32 "\n", config, relativeTimeout,
+		sApicTicsPerSec, ticks);
 
 	apic_set_lvt_initial_timer_count(ticks); // start it up
 
diff --git a/src/system/kernel/arch/x86/timers/x86_hpet.cpp b/src/system/kernel/arch/x86/timers/x86_hpet.cpp
index 07e64dfcca..6f7e347966 100644
--- a/src/system/kernel/arch/x86/timers/x86_hpet.cpp
+++ b/src/system/kernel/arch/x86/timers/x86_hpet.cpp
@@ -20,13 +20,14 @@
 
 //#define TRACE_HPET
 #ifdef TRACE_HPET
-	#define TRACE(x) dprintf x
+#	define TRACE(x...) dprintf("hpet: " x)
 #else
-	#define TRACE(x) ;
+#	define TRACE(x...) ;
 #endif
 
 #define TEST_HPET
 
+
 static struct hpet_regs *sHPETRegs;
 static volatile struct hpet_timer *sTimer;
 static uint64 sHPETPeriod;
@@ -234,9 +235,9 @@ hpet_init(struct kernel_args *args)
 
 	sHPETPeriod = HPET_GET_PERIOD(sHPETRegs);
 
-	TRACE(("hpet_init: HPET is at %p.\n\tVendor ID: %llx, rev: %llx, period: %" B_PRId64 "\n",
+	TRACE("hpet_init: HPET is at %p.\n\tVendor ID: %llx, rev: %llx, period: %" B_PRId64 "\n",
 		sHPETRegs, HPET_GET_VENDOR_ID(sHPETRegs), HPET_GET_REVID(sHPETRegs),
-		sHPETPeriod));
+		sHPETPeriod);
 
 	status_t status = hpet_set_enabled(false);
 	if (status != B_OK)
@@ -248,11 +249,11 @@ hpet_init(struct kernel_args *args)
 
 	uint32 numTimers = HPET_GET_NUM_TIMERS(sHPETRegs) + 1;
 
-	TRACE(("hpet_init: HPET supports %" B_PRIu32 " timers, and is %s bits wide.\n",
-		numTimers, HPET_IS_64BIT(sHPETRegs) ? "64" : "32"));
+	TRACE("hpet_init: HPET supports %" B_PRIu32 " timers, and is %s bits wide.\n",
+		numTimers, HPET_IS_64BIT(sHPETRegs) ? "64" : "32");
 
-	TRACE(("hpet_init: configuration: 0x%" B_PRIx64 ", timer_interrupts: 0x%" B_PRIx64 "\n",
-		sHPETRegs->config, sHPETRegs->interrupt_status));
+	TRACE("hpet_init: configuration: 0x%" B_PRIx64 ", timer_interrupts: 0x%" B_PRIx64 "\n",
+		sHPETRegs->config, sHPETRegs->interrupt_status);
 
 	if (numTimers < 3) {
 		dprintf("hpet_init: HPET does not have at least 3 timers. Skipping.\n");
diff --git a/src/system/kernel/arch/x86/timers/x86_pit.cpp b/src/system/kernel/arch/x86/timers/x86_pit.cpp
index a9007d124a..622798ddf0 100644
--- a/src/system/kernel/arch/x86/timers/x86_pit.cpp
+++ b/src/system/kernel/arch/x86/timers/x86_pit.cpp
@@ -15,6 +15,15 @@
 
 #include "pit.h"
 
+
+//#define TRACE_PIT
+#ifdef TRACE_PIT
+#	define TRACE(x...) dprintf("pit: " x)
+#else
+#	define TRACE(x...) ;
+#endif
+
+
 static bool sPITTimerInitialized = false;
 
 struct timer_info gPITTimer = {
@@ -73,13 +82,15 @@ static status_t
 pit_init(struct kernel_args *args)
 {
 	if (sPITTimerInitialized) {
+		TRACE("timer is already initialized");
 		return B_OK;
 	}
-	
+
 	install_io_interrupt_handler(0, &pit_timer_interrupt, NULL, 0);
-	pit_clear_hardware_timer();	
+	pit_clear_hardware_timer();
 
 	sPITTimerInitialized = true;
+	TRACE("timer initialized");
 
 	return B_OK;
 }
diff --git a/src/system/kernel/timer.cpp b/src/system/kernel/timer.cpp
index 28284f4ae1..dfb1193a78 100644
--- a/src/system/kernel/timer.cpp
+++ b/src/system/kernel/timer.cpp
@@ -250,8 +250,8 @@ timer_interrupt()
 	per_cpu_timer_data& cpuData = sPerCPU[smp_get_current_cpu()];
 	int32 rc = B_HANDLED_INTERRUPT;
 
-	TRACE(("timer_interrupt: time %lld, cpu %ld\n", system_time(),
-		smp_get_current_cpu()));
+	TRACE(("timer_interrupt: time %" B_PRIdBIGTIME ", cpu %" B_PRId32 "\n",
+		system_time(), smp_get_current_cpu()));
 
 	spinlock = &cpuData.lock;