| .. _syscall_perf: |
| |
| Syscall performances |
| ==================== |
| |
| The goal of this sample application is to measure the performance loss when a |
| user thread has to go through a system call compared to a supervisor thread that |
| calls the function directly. |
| |
| |
| Overview |
| ******** |
| |
| This application creates a supervisor and a user thread. |
| Then both threads call k_current_get() which returns a reference to the |
| current thread. The user thread has to go through a system call. |
| |
| Both threads are showing the number of core clock cycles and the number of |
| instructions executed while calling k_current_get(). |
| |
| |
| Sample Output |
| ************* |
| |
| .. code-block:: console |
| |
| User thread: 18012 cycles 748 instructions |
| Supervisor thread: 7 cycles 4 instructions |
| User thread: 20136 cycles 748 instructions |
| Supervisor thread: 7 cycles 4 instructions |
| User thread: 18014 cycles 748 instructions |
| Supervisor thread: 7 cycles 4 instructions |