This article mainly records my first use of NXP MCUXpresso SDK API for BSP development through the thinking of migration
This article mainly describes how to implement statistics on CPU usage based on FreeRTOS under the RT1170 platform.
Reference: https://www.fatalerrors.org/a/statistical-analysis-of-cpu-utilization-in-freertos-system.html
1. The principle of CPU usage statistics
First, if you want to realize CPU usage statistics, you need an interrupt with a granularity smaller than the system timing interrupt to realize CPU usage statistics, which is a prerequisite.
Second, you need to register in the corresponding operating system and implement the corresponding interface.
2. CPU usage statistics timer interrupt implementation
In this paper, PIT2 is used to fill this role. Add ulCpuTraceTick in the PIT2_IRQHANDLER function. This variable will be used later.
#include "fsl_debug_console.h"
#include "board.h"
#include "fsl_pit.h"
#include "pin_mux.h"
#include "clock_config.h"
#include "FreeRTOS.h"
#include "task.h"
#include "string.h"
/*----------------------------------------------*
* external variables *
*----------------------------------------------*/
/*----------------------------------------------*
* external routine prototypes *
*----------------------------------------------*/
/*----------------------------------------------*
* internal routine prototypes *
*----------------------------------------------*/
/*----------------------------------------------*
* project-wide global variables *
*----------------------------------------------*/
/*----------------------------------------------*
* module-wide global variables *
*----------------------------------------------*/
const pit_config_t PIT2_config = {
.enableRunInDebug = false
};
volatile unsigned int ulCpuTraceTick = 0;
/*----------------------------------------------*
* constants *
*----------------------------------------------*/
/*----------------------------------------------*
* macros *
*----------------------------------------------*/
/* Get source clock for PIT driver */
#define PIT_SOURCE_CLOCK CLOCK_GetRootClockFreq(kCLOCK_Root_Bus)
/* Definitions for BOARD_InitPeripheral_PIT2_Ch_0 functional group */
/* BOARD_InitPeripheral_PIT2_Ch_0 defines for PIT2 */
/* Definition of peripheral ID. */
#define PIT2_PERIPHERAL PIT2
/* Definition of clock source frequency. */
#define PIT2_CLK_FREQ 240000000UL
/* Definition of channel number for channel 0. */
#define PIT2_CHANNEL_0 kPIT_Chnl_0
/* Definition of ticks count for channel 0. */
//#define PIT2_CHANNEL_0_TICKS 2399999U
#define PIT2_CHANNEL_0_TICKS 1199999U
/* PIT2 interrupt vector ID (number). */
#define PIT2_IRQN PIT2_IRQn
/* PIT2 interrupt handler identifier. */
#define PIT2_IRQHANDLER PIT2_IRQHandler
/*----------------------------------------------*
* routines' implementations *
*----------------------------------------------*/
/* PIT2_IRQn interrupt handler */
void PIT2_IRQHANDLER(void) {
/* Place your code here */
/* Clear interrupt flag.*/
PIT_ClearStatusFlags(PIT2_PERIPHERAL, PIT2_CHANNEL_0, kPIT_TimerFlag);
ulCpuTraceTick++;
/* Add for ARM errata 838869, affects Cortex-M4, Cortex-M4F
Store immediate overlapping exception return operation might vector to incorrect interrupt. */
#if defined __CORTEX_M && (__CORTEX_M == 4U)
__DSB();
#endif
}
void PIT2_init(void) {
/* Initialize the PIT. */
PIT_Init(PIT2_PERIPHERAL, &PIT2_config);
/* Set channel 0 period to 1 s (240000000 ticks). */
PIT_SetTimerPeriod(PIT2_PERIPHERAL, PIT2_CHANNEL_0, PIT2_CHANNEL_0_TICKS);
/* Enable interrupts from channel 0. */
PIT_EnableInterrupts(PIT2_PERIPHERAL, PIT2_CHANNEL_0, kPIT_TimerInterruptEnable);
/* Enable interrupt PIT2_IRQN request in the NVIC */
EnableIRQ(PIT2_IRQN);
/* Start channel 0. */
PIT_StartTimer(PIT2_PERIPHERAL, PIT2_CHANNEL_0);
}
3. OS interface registration
Do the following configuration in FreeRTOSConfig.h
/* Run time and task stats gathering related definitions. */
-#define configGENERATE_RUN_TIME_STATS 0
+#define configGENERATE_RUN_TIME_STATS 1
#define configUSE_TRACE_FACILITY 1
#define configUSE_STATS_FORMATTING_FUNCTIONS 1
+
+extern volatile unsigned int ulCpuTraceTick;
+
+#define portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() (ulCpuTraceTick = 0ul)
+#define portGET_RUN_TIME_COUNTER_VALUE() ulCpuTraceTick
Compile the function interface to print the CPU usage:
uint8_t CPU_RunInfo[400]; //保存任务运行时间信息
//ref https://www.jianshu.com/p/cc4b948c7741
void CPU_Task(void* parameter)
{
PRINTF("CPU_Task \r\n");
while (1)
{
memset(CPU_RunInfo,0,400); //信息缓冲区清零
vTaskList((char *)&CPU_RunInfo); //获取任务运行时间信息
PRINTF("---------------------------------------------\r\n");
PRINTF("任务名 任务状态 优先级 剩余栈 任务序号\r\n");
PRINTF("%s", CPU_RunInfo);
PRINTF("---------------------------------------------\r\n");
memset(CPU_RunInfo,0,400); //信息缓冲区清零
vTaskGetRunTimeStats((char *)&CPU_RunInfo);
PRINTF("任务名 运行计数 利用率\r\n");
PRINTF("%s", CPU_RunInfo);
PRINTF("---------------------------------------------\r\n\n");
vTaskDelay(1000); /* 延时500个tick */
// PRINTF("CPU_Task \r\n");
}
}
4. Verification
Statistics of CPU usage by creating tasks:
extern void CPU_Task(void* parameter);
stat = xTaskCreate(CPU_Task, "CpuTask", configMINIMAL_STACK_SIZE + 5000, NULL, tskIDLE_PRIORITY + 1, NULL);
if (pdPASS != stat)
{
PRINTF("Failed to create awtk task");
while (1)
;
}
The actual effect is as follows:
---------------------------------------------
任务名 任务状态 优先级 剩余栈 任务序号
CpuTask X 1 5016 2
TestTask R 1 11952 1
IDLE R 0 79 4
bsp_can_t B 2 12069 3
Tmr Svc B 17 153 5
---------------------------------------------
任务名 运行计数 利用率
TestTask 1856 97%
CpuTask 40 2%
IDLE 0 <1%
bsp_can_t 0 <1%
Tmr Svc 0 <1%
---------------------------------------------
---------------------------------------------
任务名 任务状态 优先级 剩余栈 任务序号
CpuTask X 1 5008 2
TestTask R 1 11952 1
IDLE R 0 79 4
bsp_can_t B 2 12069 3
Tmr Svc B 17 153 5
---------------------------------------------
任务名 运行计数 利用率
TestTask 2088 99%
CpuTask 48 2%
IDLE 0 <1%
bsp_can_t 0 <1%
Tmr Svc 0 <1%
---------------------------------------------
---------------------------------------------
任务名 任务状态 优先级 剩余栈 任务序号
CpuTask X 1 5008 2
TestTask R 1 11952 1
IDLE R 0 79 4
bsp_can_t B 2 12069 3
Tmr Svc B 17 153 5
---------------------------------------------
任务名 运行计数 利用率
TestTask 2320 100%
CpuTask 53 2%
IDLE 0 <1%
bsp_can_t 0 <1%
Tmr Svc 0 <1%
---------------------------------------------
4. Summary
There are two problems in enabling CPU usage statistics:
First: the maximum statistics time.
Second: take up CPU resources.
Welcome to subscribe to
" Embedded Practice ", a place to share development practical experience.
The article will be published on my CSDN homepage and Toutiao platform at the same time.