Increase NCCL timeout to 3 hours (#12345)

* Increase NCCL timeout to 3 hours

When training on a large dataset using DDP, the scanning process will be very long, and it will raise NCCL timeout error. Change the default timeout 30min to 3 hours, same as ultralytics yolov8 (https://github.com/ultralytics/ultralytics/pull/3343)

Signed-off-by: Troy <wudashuo@vip.qq.com>

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Signed-off-by: Troy <wudashuo@vip.qq.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>

train.py

@@ -23,7 +23,7 @@ import subprocess
 import sys
 import time
 from copy import deepcopy
-from datetime import datetime
+from datetime import datetime, timedelta
 from pathlib import Path
 
 try:
@@ -529,7 +529,8 @@ def main(opt, callbacks=Callbacks()):
         assert torch.cuda.device_count() > LOCAL_RANK, 'insufficient CUDA devices for DDP command'
         torch.cuda.set_device(LOCAL_RANK)
         device = torch.device('cuda', LOCAL_RANK)
-        dist.init_process_group(backend='nccl' if dist.is_nccl_available() else 'gloo')
+        dist.init_process_group(backend='nccl' if dist.is_nccl_available() else 'gloo',
+                                timeout=timedelta(seconds=10800))
 
     # Train
     if not opt.evolve: