Hi
I want to measure the CPU usage of the tasks running by FreeRTOS.
I use the following code, but I see very inaccurate results.
I want to use a sliding window, or even a timer.
Is there a known solution or good practice to do so?
I use FreeRTOS with STM32H743 MCU.
#define CALCULATION_PERIOD 1000
xTaskHandle xIdleHandle = NULL;
__IO uint32_t osCPU_Usage = 0;
uint32_t osCPU_IdleStartTime = 0;
uint32_t osCPU_IdleSpentTime = 0;
uint32_t osCPU_TotalIdleTime = 0;
/* Private functions ---------------------------------------------------------*/
/**
* @brief Application Idle Hook
* @param None
* @retval None
*/
void vApplicationIdleHook(void)
{
if( xIdleHandle == NULL )
{
/* Store the handle to the idle task. */
xIdleHandle = xTaskGetCurrentTaskHandle();
}
}
/**
* @brief Application Idle Hook
* @param None
* @retval None
*/
void vApplicationTickHook (void)
{
static int tick = 0;
if(tick ++ > CALCULATION_PERIOD)
{
tick = 0;
if(osCPU_TotalIdleTime > 1000)
{
osCPU_TotalIdleTime = 1000;
}
osCPU_Usage = (100 - (osCPU_TotalIdleTime * 100) / CALCULATION_PERIOD);
osCPU_TotalIdleTime = 0;
}
}
/**
* @brief Start Idle monitor
* @param None
* @retval None
*/
void StartIdleMonitor (void)
{
if( xTaskGetCurrentTaskHandle() == xIdleHandle )
{
osCPU_IdleStartTime = xTaskGetTickCountFromISR();
}
}
/**
* @brief Stop Idle monitor
* @param None
* @retval None
*/
void EndIdleMonitor (void)
{
if( xTaskGetCurrentTaskHandle() == xIdleHandle )
{
/* Store the handle to the idle task. */
osCPU_IdleSpentTime = xTaskGetTickCountFromISR() - osCPU_IdleStartTime;
osCPU_TotalIdleTime += osCPU_IdleSpentTime;
}
}
/**
* @brief Stop Idle monitor
* @param None
* @retval None
*/
uint16_t osGetCPUUsage (void)
{
return (uint16_t)osCPU_Usage;
}
