剖析运行中的事件和 graph 吞吐量 - 2022.1 简体中文

此方法可用于对 graph stall 之前已发送或已接收的样本数量进行计数。以下示例可用于对发送至 AI 引擎端口的样本数量进行计数：

event::handle handle = event::start_profiling(gr_pl.dataout, event::io_stream_running_event_count);
if(handle==event::invalid_handle){
    printf("ERROR:Invalid handle. Only two performance counter in a AIE-PL interface tile\n");
    return 1;
} 
gr_pl.run(iterations);
sleep(2);//Wait for enough time
long long cycle_count = event::read_profiling(handle);
printf("Sample number: %d\n", cycle_count);
event::stop_profiling(handle);//Performance counter is released and cleared

以下示例可用于对接收到来自 AI 引擎端口的样本数量进行计数：

event::handle handle = event::start_profiling(gr_pl.in, event::io_stream_running_event_count);
if(handle==event::invalid_handle){
    printf("ERROR:Invalid handle. Only two performance counter in a AIE-PL interface tile\n");
    return 1;
} 
auto mm2s_run = mm2s(nullptr, OUTPUT_SIZE_MM2S);//After start profiling, send data from mm2s
gr_pl.run(iterations);
sleep(2);//Wait for enough time
long long cycle_count = event::read_profiling(handle);
printf("Sample number: %d\n", cycle_count);
event::stop_profiling(handle);//Performance counter is released and cleared

端口吞吐量定义为特定时间段内传输的样本数。运行 graph 后，可在主机代码中插入以下代码以测量端口吞吐量。为了剖析稳定状态下设计的端口吞吐量，您必须确保数据传输处于稳定状态后才能剖析端口吞吐量。

int wait_time_us=20000;
event::handle handle = event::start_profiling(gr_pl.dataout, event::io_stream_running_event_count);
if(handle==event::invalid_handle){
    printf("ERROR:Invalid handle. Only two performance counter in a AIE-PL interface tile\n");
    return 1;
} 
long long count0 = event::read_profiling(handle); 
usleep(wait_time_us); 
long long count1 = event::read_profiling(handle); 
event::stop_profiling(handle); 
long long samples = count1 - count0; 
std::cout << "num runnning samples: " << samples << std::endl; 
std::cout << "Throughput: " << (double)samples / wait_time_us << " MSPS " << std::endl;

对于 AI 引擎仿真器，此剖析方法也同样适用。在 SystemC 中您需要将 usleep 替换为 wait 函数，等待时间必须大幅缩短，因为在仿真下它要慢得多。例如，对于 AI 引擎仿真器，前述代码中的 sleep 函数可替换为以下函数调用。

wait(20,SC_US);