AutoBatch cudnn.benchmark=True fix

May resolve #9287

Signed-off-by: Glenn Jocher <glenn.jocher@ultralytics.com>

utils/autobatch.py

@@ -7,6 +7,7 @@
 
 import numpy as np
 import torch
+from torch.backends import cudnn
 
 from utils.general import LOGGER, colorstr
 from utils.torch_utils import profile
@@ -46,11 +47,14 @@ def autobatch(model, imgsz=640, fraction=0.8, batch_size=16):
 
     # Profile batch sizes
     batch_sizes = [1, 2, 4, 8, 16]
+    bm = cudnn.benchmark
+    cudnn.benchmark = False  # avoid benchmark interference https://github.com/ultralytics/yolov5/issues/9287
     try:
         img = [torch.empty(b, 3, imgsz, imgsz) for b in batch_sizes]
         results = profile(img, model, n=3, device=device)
     except Exception as e:
         LOGGER.warning(f'{prefix}{e}')
+    cudnn.benchmark = bm  # reset to original value
 
     # Fit a solution
     y = [x[2] for x in results if x]  # memory [2]