我正在通过Ubuntu 18.04LTS PyTorch C++(1.5.1,CUDA 10.1)上的预训练wordvector(glove.300d)使用torch::Embedding
模块来计算单词相似度。我相信我已经将一切都移到了GPU上,但是当我执行它时,它仍然显示(问题末尾的完整错误日志):
Expected object of device type cuda but got device type cpu for
argument #1 'self' in call to _th_index_select
(checked_dense_tensor_unwrap at /pytorch/aten/src/ATen/Utils.h:72)
我已经在 main.cpp 中检查了我的模型初始化方法,如果我仅进行初始化也可以。SimilarityModel simiModel(args, 400000, 300);
simiModel.to(device);
//model forward
torch::Tensor data = ids.index({Slice(i*batch_size, (i+1)*batch_size), Slice()}).to(torch::kInt64).to(device); //take a batch
tie(score, indice) = simiModel.forward(data); //forward and transfer score, indice to cpu for further calculation
这就是我在相似度.h 中定义相似度模型的方式:class SimilarityModel : public torch::nn::Module {
public:
int64_t topk; // num of top words;
Dictionary dict;
int64_t vocab_size;
int64_t embedding_dim;
torch::nn::Embedding embedding{nullptr};
vector<vector<float> > vec_embed;
SimilarityModel(unordered_map<string, string> args, int64_t vocab_size, int64_t embed_dim);
tuple<torch::Tensor, torch::Tensor> forward(torch::Tensor x);
};
同时,我已经在 Similarity.cpp 中的 SimilarityModel 函数中完成了初始化初始化:SimilarityModel::SimilarityModel(unordered_map<string, string> args, int64_t vocab_size, int64_t embed_dim)
:embedding(vocab_size, embed_dim) { //Embedding initialize
this->topk = stoi(args["topk"]);
vector<vector<float> > pre_embed;
tie(pre_embed, dict) = loadwordvec(args); //load pretrained wordvec from txt file
this->vocab_size = int64_t(dict.size());
this->embedding_dim = int64_t(pre_embed[0].size());
this->vec_embed = pre_embed;
this->dict = dict;
vector<float> temp_embed;
for(const auto& i : pre_embed) //faltten to 1-d
for(const auto& j : i)
temp_embed.push_back(j);
torch::Tensor data = torch::from_blob(temp_embed.data(), {this->vocab_size, this->embedding_dim}, torch::TensorOptions().dtype(torch::kFloat32)).clone(); //vector to tensor
register_module("embedding", embedding);
this->embedding = embedding.from_pretrained(data, torch::nn::EmbeddingFromPretrainedOptions().freeze(true));
}
和在相似性.cpp 中转发函数:tuple<torch::Tensor, torch::Tensor> SimilarityModel::forward(torch::Tensor x) {
auto cuda_available = torch::cuda::is_available(); //copy to gpu
torch::Device device(cuda_available ? torch::kCUDA : torch::kCPU);
torch::Tensor wordvec;
wordvec = this->embedding->forward(x).to(device); //python:embedding(x)
torch::Tensor similarity_score = wordvec.matmul(this->embedding->weight.transpose(0, 1)).to(device);
torch::Tensor score, indice;
tie(score, indice) = similarity_score.topk(this->topk, -1, true, true); //Tensor.topk(int64_t k, int64_t dim, bool largest = true, bool sorted = true)
score = score.to(device);
indice = indice.to(device);
score.slice(1, 1, score.size(1)); //Tensor.slice(int64_t dim, int64_t start, int64_t end, int64_t step)
indice.slice(1, 1, indice.size(1));
return {score.cpu(), indice.cpu()}; //transfer to cpu for further calculation
}
至于 forward()中的中间变量,也已放入GPU。但是,我完全不知道将哪一个留在CPU中,并且错误日志没有太大帮助。我已经尝试过Expected object of device type cuda but got device type cpu for argument #1 'self' in call to _th_index_select中的方法来执行SimilarityModel().to(device)
,但这不起作用。我仍然很难阅读此错误日志,并希望获得有关如何调试此类问题的说明。错误日志:
terminate called after throwing an instance of 'c10::Error'
what(): Expected object of device type cuda but got device type cpu for argument #1 'self' in call to _th_index_select (checked_dense_tensor_unwrap at /pytorch/aten/src/ATen/Utils.h:72)
frame #0: c10::Error::Error(c10::SourceLocation, std::string const&) + 0x46 (0x7fb566a27536 in /home/switchsyj/Downloads/libtorch/lib/libc10.so)
frame #1: <unknown function> + 0x101a80b (0x7fb520fa380b in /home/switchsyj/Downloads/libtorch/lib/libtorch_cuda.so)
frame #2: <unknown function> + 0x105009c (0x7fb520fd909c in /home/switchsyj/Downloads/libtorch/lib/libtorch_cuda.so)
frame #3: <unknown function> + 0xf9d76b (0x7fb520f2676b in /home/switchsyj/Downloads/libtorch/lib/libtorch_cuda.so)
frame #4: <unknown function> + 0x10c44e3 (0x7fb558d224e3 in /home/switchsyj/Downloads/libtorch/lib/libtorch_cpu.so)
frame #5: at::native::embedding(at::Tensor const&, at::Tensor const&, long, bool, bool) + 0x2e2 (0x7fb558870712 in /home/switchsyj/Downloads/libtorch/lib/libtorch_cpu.so)
frame #6: <unknown function> + 0x114ef9d (0x7fb558dacf9d in /home/switchsyj/Downloads/libtorch/lib/libtorch_cpu.so)
frame #7: <unknown function> + 0x1187b4d (0x7fb558de5b4d in /home/switchsyj/Downloads/libtorch/lib/libtorch_cpu.so)
frame #8: <unknown function> + 0x2bfe42f (0x7fb55a85c42f in /home/switchsyj/Downloads/libtorch/lib/libtorch_cpu.so)
frame #9: <unknown function> + 0x1187b4d (0x7fb558de5b4d in /home/switchsyj/Downloads/libtorch/lib/libtorch_cpu.so)
frame #10: <unknown function> + 0x32b63a9 (0x7fb55af143a9 in /home/switchsyj/Downloads/libtorch/lib/libtorch_cpu.so)
frame #11: torch::nn::EmbeddingImpl::forward(at::Tensor const&) + 0x71 (0x7fb55af127b1 in /home/switchsyj/Downloads/libtorch/lib/libtorch_cpu.so)
frame #12: SimilarityModel::forward(at::Tensor) + 0xa9 (0x55c96b8e5793 in ./demo)
frame #13: main + 0xaba (0x55c96b8bfe5c in ./demo)
frame #14: __libc_start_main + 0xe7 (0x7fb51edf5b97 in /lib/x86_64-linux-gnu/libc.so.6)
frame #15: _start + 0x2a (0x55c96b8bd74a in ./demo)
Aborted (core dumped)
最佳答案
根据错误消息,当您运行Tensor
时,以下两个SimilarityModel::forward()
之一不在GPU中:
this->embedding->weight
x
鉴于错误指向
argument #1
,我想说weight
是CPU上的那个。这是
index.select
的电话:Tensor embedding(const Tensor & weight, const Tensor & indices,
int64_t padding_idx, bool scale_grad_by_freq, bool sparse) {
auto indices_arg = TensorArg(indices, "indices", 1);
checkScalarType("embedding", indices_arg, kLong);
// TODO: use tensor.index() after improving perf
if (indices.dim() == 1) {
return weight.index_select(0, indices);
}
auto size = indices.sizes().vec();
for (auto d : weight.sizes().slice(1)) {
size.push_back(d);
}
return weight.index_select(0, indices.reshape(-1)).view(size);
}
首先,尝试将权重直接移至GPU。如果可行,则意味着当您调用TORCH_MODULE(SimilarityModel)
并将模型移至设备时,它也应该可行。请记住,在这种情况下,您必须将名称更改为SimilarityModelImpl
(Name + Impl)。否则,它将无法正常工作。