FreeRTOS with configUSE_PREEMPTION == 0 causes IDLE task to continously generated "Task Switched-In" Events

[schilkp]

This happens because it continously yields:

static portTASK_FUNCTION( prvIdleTask, pvParameters )
{
    /* Stop warnings. */
    ( void ) pvParameters;

    /** THIS IS THE RTOS IDLE TASK - WHICH IS CREATED AUTOMATICALLY WHEN THE
     * SCHEDULER IS STARTED. **/

    /* In case a task that has a secure context deletes itself, in which case
     * the idle task is responsible for deleting the task's secure context, if
     * any. */
    portALLOCATE_SECURE_CONTEXT( configMINIMAL_SECURE_STACK_SIZE );

    #if ( configNUMBER_OF_CORES > 1 )
    {
        /* SMP all cores start up in the idle task. This initial yield gets the application
         * tasks started. */
        taskYIELD();
    }
    #endif /* #if ( configNUMBER_OF_CORES > 1 ) */

    for( ; configCONTROL_INFINITE_LOOP(); )
    {
        /* See if any tasks have deleted themselves - if so then the idle task
         * is responsible for freeing the deleted task's TCB and stack. */
        prvCheckTasksWaitingTermination();

        #if ( configUSE_PREEMPTION == 0 )
        {
            /* If we are not using preemption we keep forcing a task switch to
             * see if any other task has become available.  If we are using
             * preemption we don't need to do this as any task becoming available
             * will automatically get the processor anyway. */
            taskYIELD();
        }
        #endif /* configUSE_PREEMPTION */

        ....