I would like to train a model where it contains 2 sub-modules. I would like to train sub-model 1 in one gpu and sub-model 2 in another gpu. How would i do in pytorch? I tried specifying cuda device separately for each sub-module but it throws an error.
Error: RuntimeError: tensors are on different GPUs
class Net(nn.Module):
    def __init__(self):
        super(Net, self).__init__()
        self.conv1 = nn.Conv2d(1, 10, kernel_size=5)
        self.conv2 = nn.Conv2d(10, 20, kernel_size=5).cuda(device=1)
        self.conv2_drop = nn.Dropout2d()
        self.fc1 = nn.Linear(320, 50)
        self.fc2 = nn.Linear(50, 10)

    def forward(self, x):
        x = F.relu(F.max_pool2d(self.conv1(x), 2))
        x = x.cuda(device=1)
        conv2_in_gpu1 = self.conv2(x)
        x = x.cuda(device=0)
        x = F.relu(F.max_pool2d(self.conv2_drop(conv2_in_gpu1), 2))
        x = x.view(-1, 320)
        x = F.relu(self.fc1(x))
        x = F.dropout(x, training=self.training)
        x = self.fc2(x)
        return F.log_softmax(x, dim=1)

model = Net()
if args.cuda:
    model.cuda(device=0)

This is just an example of what i was trying to achieve. I would like the self.conv2 to be performed in gpu1 and rest in gpu0.