| Supported Targets | ESP32 | ESP32-C2 | ESP32-C3 | ESP32-C5 | ESP32-C6 | ESP32-H2 | ESP32-P4 | ESP32-S2 | ESP32-S3 | | ----------------- | ----- | -------- | -------- | -------- | -------- | -------- | -------- | -------- | -------- | # FreeRTOS Real Time Stats Example (See the README.md file in the upper level 'examples' directory for more information about examples.) FreeRTOS provides the function `vTaskGetRunTimeStats()` to obtain CPU usage statistics of tasks. However, these statistics are with respect to the entire runtime of FreeRTOS (i.e. **run time stats**). Furthermore, statistics of `vTaskGetRunTimeStats()` are only valid whilst the timer for run time statistics has not overflowed. This example demonstrates how to get CPU usage statistics of tasks with respect to a specified duration (i.e. **real time stats**) rather than over the entire runtime of FreeRTOS. The `print_real_time_stats()` function of this example demonstrates how this can be achieved. ## How to use example ### Hardware Required This example should be able to run on any commonly available ESP32 development board. ### Configure the project ``` idf.py menuconfig ``` * Select `Enable FreeRTOS to collect run time stats` under `Component Config > FreeRTOS` (this should be enabled in the example by default) * `Choose the clock source for run time stats` configured under `Component Config > FreeRTOS`. The `esp_timer` should be selected be default. This option will affect the time unit resolution in which the statistics are measured with respect to. ### Build and Flash Build the project and flash it to the board, then run monitor tool to view serial output: ``` idf.py -p PORT flash monitor ``` (Replace PORT with the name of the serial port to use.) (To exit the serial monitor, type ``Ctrl-]``.) See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects. ## Example Output The example should have the following log output: ``` ... Getting real time stats over 100 ticks | Task | Run Time | Percentage | stats | 1304 | 0% | IDLE0 | 206251 | 10% | IDLE1 | 464785 | 23% | spin2 | 225389 | 11% | spin0 | 227174 | 11% | spin4 | 225303 | 11% | spin1 | 207264 | 10% | spin3 | 225331 | 11% | spin5 | 225369 | 11% | Tmr Svc | 0 | 0% | esp_timer | 0 | 0% | ipc1 | 0 | 0% | ipc0 | 0 | 0% Real time stats obtained ... ``` ## Example Breakdown ### Spin tasks During the examples initialization process, multiple `spin` tasks are created. These tasks will simply spin a certain number of CPU cycles to consume CPU time, then block for a predetermined period. ### Understanding the stats From the log output, it can be seen that the spin tasks consume nearly an equal amount of time over the specified stats collection period of `print_real_time_stats()`. The real time stats also display the CPU time consumption of other tasks created by default in ESP-IDF (e.g. `IDLE` and `ipc` tasks).