Hi
I have installed cuda8 pytorch 0.4.1 with conda.
the back-prop looks too slow.
here is the report using util.bottleneck:

WX20180911-170102@2x.png1968×1440 326 KB

here is my test code for main training process in debug mode
start1 = time.time()
for _ in range(100):
    word_in1 = torch.cuda.LongTensor(word_in)
    word_out1 = torch.cuda.LongTensor(word_out)
    label = torch.cuda.DoubleTensor(train_label)
    emb_u =  nn.functional.embedding(word_in1,syn0)
    emb_v =  nn.functional.embedding(word_out1,syn1)
    outs = torch.sigmoid(torch.sum(torch.mul(emb_u, emb_v), dim=-1))
    loss = Lossfunc.cuda()(outs, label)
    optimizer.zero_grad()
    loss.backward()
    optimizer.step()
print (time.time() - start1)

    optimizer = optim.SGD([syn0, syn1], lr=alpha)
    Lossfunc = nn.BCELoss(reduction='sum')

and I found the last three lines(.zero_grad(),.backward(),.step()) occupy most of the time.
So what should i do next?