`train_fashion_mnist_example` accuracy drops when `num_workers > 1`

I ran the script train_fashion_mnist_example.py with num_workers=1 got 44%,

However, when I set num_workers=4, the accuracy dropped drastically that only got less than 10%.

It seems that each process model only used 1/4 data to train and their weights are not gathered.

Have anyone met this issue? Thank you.

Hey @tangcc1127, thanks for pointing this out. It seems like the primary bug in the code was that the total size being used to calculate accuracy = correct / size was incorrectly using the global size rather than the worker size.

I made a fix for this here. Let me know if this looks right to you!

It does work! Thank u. len(dataset) may not divisible by num_workers so I count the total number of validate data of each worker by myself.