mirror of
https://github.com/espressif/esp-idf.git
synced 2024-10-05 20:47:46 -04:00
de682a13b1
The following commit updates the first half of the the system example README files. Some other changes were also made: * Updated base_mac_address example * Moved contents in GCOV README to GCOV docs * Some *main.c file names updated * Updated example README template
72 lines
2.6 KiB
Markdown
72 lines
2.6 KiB
Markdown
# 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). |