Hey,
I’m indeed using torch.multiprocessing (and not torch.distributed nor torch.nn.parallel).
I’m not using any CUDA-related feature : it’s CPU only (in fact I did not performed the full pytorch install with CUDA).
I will try with spawn, but I choosed fork on purpose, because it was more practical with the ability to init process before starting it.
Before that, let’s have a look on that thread you send me: the symptom looks like very similar !
Thanks a lot for your help