Index out of range on multi-GPU (8 gpus ) after first epoch

[akshitac8]

Expected results

Successful Training

Actual results

Detailed steps to reproduce

After Running the main and on completion of first epoch, I get an index out of range error with drop_last = False on

mini_kwargs = dict([(k, v[i]) for k, v in kwargs.items()])

I tried to trace the error reason and came to know that after first epoch last 3 device ids i.e, 5,6,7 which is very weird behaviour.
E.g.:

CUDA_VISIBLE_DEVICES=4,5,6,7 python tools/train_net_step.py --dataset dota_patches --cfg configs/baselines/e2e_mask_rcnn_X-101-64x4d-FPN_2x.yaml --bs 8 --nw 8

System information

• Operating system: ubuntu16.04
• CUDA version: 9.0
• cuDNN version: 7.0
• GPU models (for all devices if they are not all the same):?
• python version: 3.6
• pytorch version: 0.4.0