[BUG] Can't pickle local object 'instrument_w_nvtx.<locals>.wrapped_fn'

[annopackage]

Describe the bug
A clear and concise description of what the bug is.
bug occurs while calling dataloader with multi num workers.
Here, ’trainer‘ is initialized from transformers. If I only debug with dataloader as follows, the code works.
‘’‘
for _, data in tqdm(enumerate(trainer.get_train_dataloader())):
print('dataloader: ', _, data.keys())
’‘’

However, if running trainer.train(), then the code throws the error as the title.

To Reproduce
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3. Scroll down to '....'
4. See error

Expected behavior
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ds_report output
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Screenshots

System info (please complete the following information):

• OS: [e.g. Ubuntu 18.04]
• GPU count and types [e.g. two machines with x8 A100s each]
• Interconnects (if applicable) [e.g., two machines connected with 100 Gbps IB]
• Python version
• Any other relevant info about your setup

Launcher context
launching your experiment with the deepspeed launcher, MPI, or something else?

Docker context
Do not use docker.

Additional context
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[loadams]

Hi @annopackage - can you share a full minimal repro script with us please?

[annopackage]

hi, thanks for your quick reply. My dataloader contains function for video decoding with gpu, which maybe the reason of the issue. If I comment this part, the dataset with transformer and deepspeed works well. The minimal script for reproduction would be provided later.

[annopackage]

@loadams Hi, the reason to the issue is multiprocessing_context. I think the error could be reproduced while setting multiprocessing_context in dataloader as 'spawn'.

[annopackage]

With zero2 and spawn, the code runs well.
With zero3 and fork, the code runs well.
With zero3 and spawn, the bug occurs.