The Execution Time Difference Between Event_Profiling and Steady Clock

I am trying to profile my code and I am getting different results each time I run the code.

auto start = std::chrono::steady_clock::now();
foo()      
auto end = std::chrono::steady_clock::now();
time = std::chrono::duration_cast<std::chrono::nanoseconds>(end - start).count();

why is this giving me different results than using

start_kernel_time = event.get_profiling_info<info::event_profiling::command_start>();
end_kernel_time = event.get_profiling_info<info::event_profiling::command_end>();
time_kernel = (end_kernel_time - start_kernel_time) / kNs; // kNs = 1e9

I run the code several times and interesting thing is steady_clock version first printed out 6.7 seconds and then in the second run printed out 0.07 seconds ( unrealistic) then the event profiling was printed the ~0.64 seconds which made more sense. Why it is different ?

I am using oneapi 2023 with icpx compiler

未指定源文件、测试或示例入口点。首先使用所述的 oneAPI 2023 和 icpx 设置复现两个计时片段，然后将主机 steady-clock 时间间隔与 event_profiling command_start 和 command_end 进行比较；记录差异原因以及可靠的执行时间测量方法后，即可视为完成。