frequency (N) of each IrqID. We store the information calculated in the first
EventRequest in an array called FirstRequestIrqExit.
In the second EventRequest, we compute the Sum ((xi -Xa)^2) and store this information
- in a array called SumArray. The function CalculateStandardDeviation() uses FirstRequestIrqExit
+ in a array called SumArray. The function CalculateDurationStandardDeviation() uses FirstRequestIrqExit
and SumArray arrays to calculate the standard deviation.
+
+
+CPUID: processor ID
+
+IrqId: IRQ ID
+
+Frequency (Hz): the number of interruptions per second (Hz)
+
+Total Duration (nsec): the sum of each interrupt duration in nsec
+
+Duration standard deviation (nsec): taken from http://en.wikipedia.org/wiki/Standard_deviation
+Duration Standard_deviation = sqrt(1/N Sum ((xi -Xa)^2)) where
+N: number of interrupts
+xi: duration of an interrupt (nsec)
+Xa: average duration (nsec)
+
+Max IRQ handler duration (nsec) [time interval]: the longest IRQ handler duration in nsec.
+
+Average period (nsec): 1/frequency
+
+
+Period Standard_deviation = sqrt(1/N Sum ((xi -Xa)^2)) where
+N: number of interrupts
+xi: 1/duration of an interrupt
+Xa: 1/frequency
+
*******************************************************************/
guint irqId;
guint frequency;
guint64 sumOfDurations;
+ guint64 sumOfPeriods;
}SumId;
static gboolean SecondRequestIrqExitCallback(void *hook_data, void *call_data);
static void CalculateXi(LttEvent *event, InterruptEventData *event_data);
static void SumItems(gint irq_id, LttTime Xi, InterruptEventData *event_data);
-static int CalculateStandardDeviation(gint id, InterruptEventData *event_data);
+static int CalculateDurationStandardDeviation(gint id, InterruptEventData *event_data);
+static int CalculatePeriodStandardDeviation(gint id, InterruptEventData *event_data);
static int FrequencyInHZ(gint frequency, TimeWindow time_window);
-
+static guint64 CalculatePeriodInnerPart(guint Xi, guint FrequencyHZ);
/* Enumeration of the columns */
enum{
CPUID_COLUMN,
G_TYPE_UINT64, /* Duration */
G_TYPE_INT, /* standard deviation */
G_TYPE_STRING, /* Max IRQ handler */
- G_TYPE_DOUBLE, /* Average period */
- G_TYPE_DOUBLE /* period standard deviation */
+ G_TYPE_INT, /* Average period */
+ G_TYPE_INT /* period standard deviation */
);
event_viewer_data->TreeView = gtk_tree_view_new_with_model (GTK_TREE_MODEL (event_viewer_data->ListStore));
irq.max_irq_handler.end_time = time_exit;
irq.max_irq_handler.duration = ltt_time_sub(time_exit, e->event_time);
-
g_array_append_val (FirstRequestIrqExit, irq);
}
else
static void SumItems(gint irq_id, LttTime Xi, InterruptEventData *event_data)
{
gint i;
- guint time_in_ns;
+ guint Xi_in_ns;
- gint temp;
+ gint duration_inner_part;
+ guint64 period_inner_part;
Irq *average;
SumId *sumItem;
SumId sum;
+ int FrequencyHZ = 0;
gboolean notFound = FALSE;
GArray *FirstRequestIrqExit = event_data->FirstRequestIrqExit;
GArray *SumArray = event_data->SumArray;
- time_in_ns = Xi.tv_sec;
- time_in_ns *= NANOSECONDS_PER_SECOND;
- time_in_ns += Xi.tv_nsec;
+ Xi_in_ns = Xi.tv_sec;
+ Xi_in_ns *= NANOSECONDS_PER_SECOND;
+ Xi_in_ns += Xi.tv_nsec;
for(i = 0; i < FirstRequestIrqExit->len; i++)
{
average = &g_array_index(FirstRequestIrqExit,Irq,i);
if(irq_id == average->id)
{
- temp = time_in_ns - average->average_duration;
- sum.sumOfDurations = pow (temp , 2);
- //printf("one : %d\n", sum.sumOfDurations);
+ duration_inner_part = Xi_in_ns - average->average_duration;
+ FrequencyHZ = FrequencyInHZ(average->frequency, event_data->time_window);
+
sum.irqId = irq_id;
sum.frequency = average->frequency;
+ sum.sumOfDurations = pow (duration_inner_part , 2);
+ period_inner_part = CalculatePeriodInnerPart(Xi_in_ns, FrequencyHZ);
+ sum.sumOfPeriods = period_inner_part;
if(event_data->SumArray->len == NO_ITEMS)
{
g_array_append_val (SumArray, sum);
}
else
- {
-
+ {
for(i = 0; i < SumArray->len; i++)
{
sumItem = &g_array_index(SumArray, SumId, i);
{
notFound = TRUE;
sumItem->sumOfDurations += sum.sumOfDurations;
-
- }
+ sumItem->sumOfPeriods += sum.sumOfPeriods;
+ }
}
if(!notFound)
{
g_array_append_val (SumArray, sum);
}
-
-
+
}
}
}
}
+static guint64 CalculatePeriodInnerPart(guint Xi, guint FrequencyHZ)
+{
+
+ double periodInSec; /*period in sec*/
+ int periodInNSec;
+ gint difference;
+ guint64 result;
+ periodInSec = (double)1/FrequencyHZ;
+ periodInSec *= NANOSECONDS_PER_SECOND;
+ periodInNSec = (int)periodInSec;
+
+ difference = Xi - periodInNSec;
+ result = pow (difference , 2);
+
+
+ return result;
+
+
+
+}
/**
* This function displays the result on the viewer
*
GtkTreeIter iter;
guint64 real_data;
guint maxIRQduration;
- double period;
+ double periodInSec;
+ int periodInNsec;
char maxIrqHandler[80];
InterruptEventData *event_data = (InterruptEventData *)hook_data;
GArray *FirstRequestIrqExit = event_data->FirstRequestIrqExit;
int FrequencyHZ = 0;
- period = 0.0;
+ periodInSec = 0;
gtk_list_store_clear(event_data->ListStore);
for(i = 0; i < FirstRequestIrqExit->len; i++)
{
element.max_irq_handler.start_time.tv_nsec, element.max_irq_handler.end_time.tv_sec, \
element.max_irq_handler.end_time.tv_nsec) ;
FrequencyHZ = FrequencyInHZ(element.frequency,event_data->time_window);
+
if(FrequencyHZ != 0)
{
- period =(double)1/FrequencyHZ;
+ periodInSec = (double)1/FrequencyHZ;
+ periodInSec *= NANOSECONDS_PER_SECOND;
+ periodInNsec = (int)periodInSec;
+ //printf("period1:%d\n", periodInNsec);
}
-
+
gtk_list_store_append (event_data->ListStore, &iter);
gtk_list_store_set (event_data->ListStore, &iter,
CPUID_COLUMN, element.cpu_id,
IRQ_ID_COLUMN, element.id,
FREQUENCY_COLUMN, FrequencyHZ,
DURATION_COLUMN, real_data,
- DURATION_STANDARD_DEV_COLUMN, CalculateStandardDeviation(element.id, event_data),
+ DURATION_STANDARD_DEV_COLUMN, CalculateDurationStandardDeviation(element.id, event_data),
MAX_IRQ_HANDLER_COLUMN, maxIrqHandler,
- AVERAGE_PERIOD , period,
+ AVERAGE_PERIOD , periodInNsec,
+ PERIOD_STANDARD_DEV_COLUMN, CalculatePeriodStandardDeviation(element.id, event_data),
-1);
}
+/**
+ * This function converts the number of interrupts over a time window to
+ * frequency in HZ
+ */
static int FrequencyInHZ(gint frequency, TimeWindow time_window)
{
guint64 frequencyHz = 0;
- double timeSec;
-
- timeSec = ltt_time_to_double(time_window.time_width);
- double result = (timeSec/NANOSECONDS_PER_SECOND);
- frequencyHz = frequency / result;
+ double timeSec; // time in second
+ double result;
+ result = ltt_time_to_double(time_window.time_width);
+ timeSec = (result/NANOSECONDS_PER_SECOND); //time in second
+ frequencyHz = frequency / timeSec;
return frequencyHz;
}
/**
- * This function calculatees the standard deviation
+ * This function calculates the duration standard deviation
*
*/
-static int CalculateStandardDeviation(gint id, InterruptEventData *event_data)
+static int CalculateDurationStandardDeviation(gint id, InterruptEventData *event_data)
{
int i;
SumId sumId;
}
return deviation;
}
+
+
+/**
+ * This function calculates the period standard deviation
+ *
+ */
+static int CalculatePeriodStandardDeviation(gint id, InterruptEventData *event_data)
+{
+ int i;
+ SumId sumId;
+ guint64 inner_component;
+ guint64 period_standard_deviation = 0;
+ for(i = 0; i < event_data->SumArray->len; i++)
+ {
+ sumId = g_array_index(event_data->SumArray, SumId, i);
+ if(id == sumId.irqId)
+ {
+ inner_component = sumId.sumOfPeriods / sumId.frequency;
+ period_standard_deviation = sqrt(inner_component);
+ }
+ }
+
+ return period_standard_deviation;
+}
/*
* This function is called by the main window
* when the time interval needs to be updated.
projects / lttv.git / commitdiff
