目录

背景

代码

参考：

---

背景

评估模型的推理时间时有需要注意的地方。如torch.cuda.synchronize()，因为pytorch代码执行时异步的，使用该代码会等待gpu上所有操作结束后再接着运行代码、计算时间等【1】。

代码

函数【2】：

import time
def measure_inference_speed(model, data, max_iter=200, log_interval=50):
    model.eval()

    # the first several iterations may be very slow so skip them
    num_warmup = 5
    pure_inf_time = 0
    fps = 0

    # benchmark with 2000 image and take the average
    for i in range(max_iter):

        torch.cuda.synchronize()
        start_time = time.perf_counter()

        with torch.no_grad():
            model(*data)

        torch.cuda.synchronize()
        elapsed = time.perf_counter() - start_time

        if i >= num_warmup:
            pure_inf_time += elapsed
            if (i + 1) % log_interval == 0:
                fps = (i + 1 - num_warmup) / pure_inf_time
                print(
                    f'Done image [{i + 1:<3}/ {max_iter}], '
                    f'fps: {fps:.1f} img / s, '
                    f'times per image: {1000 / fps:.1f} ms / img',
                    flush=True)

        if (i + 1) == max_iter:
            fps = (i + 1 - num_warmup) / pure_inf_time
            print(
                f'Overall fps: {fps:.1f} img / s, '
                f'times per image: {1000 / fps:.1f} ms / img',
                flush=True)
            break
    return fps

 调用【2】：

import measure_inference_speed
net = net.cuda()
data = torch.randn((1, 6, 128, 128)).cuda()
measure_inference_speed(net, (data,))

参考：

【1】

pytorch 正确的测试时间的代码 torch.cuda.synchronize()_枯叶蝶KYD的博客-CSDN博客_pytorch 时间

【2】

NAFNet/NAFSSR_arch.py at main · megvii-research/NAFNet · GitHub