ModuleNotFoundError: No module named 'mmcv.parallel'

[Liqq1]

您好, 我的程序中涉及：

from mmcv.parallel import MMDataParallel, MMDistributedDataParallel

但出现以下错误：

ModuleNotFoundError: No module named 'mmcv.parallel'

我的版本为：

mmcv                2.0.0rc4
mmengine            0.7.2
mmsegmentation      1.0.0
torch               1.12.1+cu113
torchaudio          0.12.1+cu113
torchvision         0.13.1+cu113

[winnieepooh]

同样的问题，请问您解决了吗

[Liqq1]

同样的问题，请问您解决了吗

你好，我暂时“解决”了(因为我还是没找到最新版的mmcv的parallel变为什么了，我降低了版本)；我现在的版本为：

torch               1.8.1+cu101
torchaudio          0.8.1
torchvision         0.9.1+cu101

mmcv-full           1.4.0
mmengine            0.7.2
mmsegmentation      0.14.0

我的安装命令为：

pip install mmcv-full==1.4.0 -f https://download.openmmlab.com/mmcv/dist/cu112/torch1.6.0/index.html

pip install torch==1.8.1+cu101 torchvision==0.9.1+cu101 torchaudio==0.8.1 -f https://download.pytorch.org/whl/torch_stable.html

引起上述问题的原因见：https://mmcv.readthedocs.io/en/latest/compatibility.html

[zhouzaida]

Hi, the parallel has been removed from MMCV since v2.0.0. More details can be found at https://github.com/open-mmlab/mmcv/blob/main/docs/en/compatibility.md#v200.

[Liqq1]

那在v2.0.0中怎么使用parallel包中的相关内容呢？例如， MMDataParallel, MMDistributedDataParallel

[MartinYYYYan]

同问，
那在v2.0.0中怎么使用parallel包中的相关内容呢？例如， MMDataParallel, MMDistributedDataParallel

[T0L0ve]

+1

[SimLuo2014]

+1

[micklexqg]

同问，
既然删了，那在v2.0.0中怎么使用parallel呢？

[zhouzaida]

Hi, the MMDistributedDataParallel in MMCV has been migrated to MMEngine (https://github.com/open-mmlab/mmengine/blob/426a565908e47f791938baa3a876a87de306b436/mmengine/model/wrappers/distributed.py#L16).

If the distributed environment is initialized (see https://mmengine.readthedocs.io/en/latest/common_usage/speed_up_training.html#distributed-training for details about how to launch distributed training), the MMDistributedDataParallel will be automatically wrapped for the model.

The logic to wrapper the model is in https://github.com/open-mmlab/mmengine/blob/426a565908e47f791938baa3a876a87de306b436/mmengine/runner/runner.py#L408.

Of course, we can pass the model_wrapper_cfg to the cfg of Runner in MMEngine to use the MMDistributedDataParallel.

runner = Runner(
    model=ResNet18(),
    work_dir='./work_dir',
    train_dataloader=train_dataloader_cfg,
    optim_wrapper=dict(
        type='AmpOptimWrapper',
        # If you want to use bfloat16, uncomment the following line
        # dtype='bfloat16',  # valid values: ('float16', 'bfloat16', None)
        optimizer=dict(type='SGD', lr=0.001, momentum=0.9)),
    train_cfg=dict(by_epoch=True, max_epochs=3),
    cfg=dict(model_wrapper_cfg=dict(type=MMDistributedDataParallel),
)
runner.train()

In addition, we also provide several documentation to help migration. https://mmengine.readthedocs.io/en/latest/migration/runner.html

[garychan22]

Hi, the parallel has been removed from MMCV since v2.0.0. More details can be found at https://github.com/open-mmlab/mmcv/blob/main/docs/en/compatibility.md#v200.

so where to move? I have not found an easy way to transfer the code in older version to latest version when the code using

from mmcv.parallel import MMDataParallel, DataContainer, collate
model = MMDataParallel(model, device_ids=[0])

[TMaysGGS]

Hi, the parallel has been removed from MMCV since v2.0.0. More details can be found at https://github.com/open-mmlab/mmcv/blob/main/docs/en/compatibility.md#v200.

so where to move? I have not found an easy way to transfer the code in older version to latest version when the code using

from mmcv.parallel import MMDataParallel, DataContainer, collate
model = MMDataParallel(model, device_ids=[0])

I have the same question like this. I searched the repo open-mmlab/mmengine for like "MMDataParallel" and was not able to find a substitute function for mmcv.parallel.MMDataParallel.

[cr7Alex]

+1

[ghazalmatt3r]

+1