Unify CUDA stream in Tensor CopyFrom interface (#4692)

* init

* unify CopyFrom interface

* fix gpu build error

* fix bug in tensor_py.h

* refine code comments and add TODO list

* fix conflicts in FeedOp and FetchOp

paddle/framework/tensor.h

@@ -87,26 +87,31 @@ class Tensor {
   /**
    * @brief   Copy the content of external tensor to a new place.
    *
-   * @param[in] src   The external tensor.
-   * @param[in] ctx   The device context contains place where to store.
+   * @param[in] src        The external tensor.
+   * @param[in] dst_place  The dst place.
+   * @param[in] ctx        The device context contains device resources.
    *
    * @note    CopyFrom supports CPU <-> GPU, GPU <-> GPU.
    */
+  // TODO(qijun): https://github.com/PaddlePaddle/Paddle/issues/4647
+  // Remove `CopyFrom` and `CopyFromVector` from Tensor interface
+  // and make them global functions
   template <typename T>
-  inline void CopyFrom(const Tensor& src, const platform::Place& dst_place);
+  inline void CopyFrom(const Tensor& src, const platform::Place& dst_place,
+                       const platform::DeviceContext& ctx);
 
   /**
    * @brief   Copy the content of an external vector to a tensor.
    *
-   * @param[in] src   The external vector.
-   * @param[in] ctx   The device context contains place where to store.
+   * @param[in] src        The external tensor.
+   * @param[in] ctx        The device context contains device resources.
    *
    * * @note    CopyFromVector assumes that the tensor has been resized
    *            before invoking.
    */
   template <typename T>
   inline void CopyFromVector(const std::vector<T>& src,
-                             const platform::Place& dst_place);
+                             const platform::DeviceContext& ctx);
 
   /**
    * @brief   Return the slice of the tensor.

paddle/framework/tensor_array.cc

@@ -95,7 +95,8 @@ void TensorArray::Write(size_t index, const LoDTensor& value) {
 
   values_[index].Resize(value.dims());
   values_[index].mutable_data<value_type>(platform::CPUPlace());
-  values_[index].CopyFrom<value_type>(value, platform::CPUPlace());
+  values_[index].CopyFrom<value_type>(value, platform::CPUPlace(),
+                                      platform::CPUDeviceContext());
 }
 
 void TensorArray::WriteShared(size_t index, const LoDTensor& value) {
@@ -151,7 +152,8 @@ LoDTensor TensorArray::Stack() const {
 
   for (size_t idx = 0; idx < size(); idx++) {
     result.Slice<value_type>(idx, idx + 1)
-        .CopyFrom<value_type>(Read(idx), platform::CPUPlace());
+        .CopyFrom<value_type>(Read(idx), platform::CPUPlace(),
+                              platform::CPUDeviceContext());
   }
   return result;
 }
@@ -182,7 +184,8 @@ void TensorArray::Unstack(const LoDTensor& source, bool data_shared) const {
       // copy
       value.Resize(value_dims);
       value.CopyFrom<value_type>(source.Slice<value_type>(elem, elem + 1),
-                                 platform::CPUPlace());
+                                 platform::CPUPlace(),
+                                 platform::CPUDeviceContext());
     }
   }
 }
@@ -236,7 +239,8 @@ LoDTensor DynamicBatchUnpacker::GetBatch(size_t index) {
     auto target = result.Slice<value_type>(i, i + 1);
     auto source_ = source->Slice<value_type>(index, index + 1);
 
-    target.CopyFrom<value_type>(source_, platform::CPUPlace());
+    target.CopyFrom<value_type>(source_, platform::CPUPlace(),
+                                platform::CPUDeviceContext());
   }
 
   return result;
@@ -269,7 +273,8 @@ LoDTensor PackDynamicBatch(const std::vector<LoDTensor>& source,
       if (index >= seq_meta.end) break;
       auto source_ = source[batch_id].Slice<float>(seq_id, seq_id + 1);
       auto target = result.Slice<float>(index, index + 1);
-      target.CopyFrom<float>(source_, platform::CPUPlace());
+      target.CopyFrom<float>(source_, platform::CPUPlace(),
+                             platform::CPUDeviceContext());
     }
   }
 

paddle/framework/tensor_impl.h

@@ -88,7 +88,8 @@ inline Tensor& Tensor::ShareDataWith(const Tensor& src) {
 
 template <typename T>
 inline void Tensor::CopyFrom(const Tensor& src,
-                             const platform::Place& dst_place) {
+                             const platform::Place& dst_place,
+                             const platform::DeviceContext& ctx) {
   src.check_memory_size<T>();
   Resize(src.dims());
 
@@ -106,26 +107,45 @@ inline void Tensor::CopyFrom(const Tensor& src,
 #ifdef PADDLE_WITH_CUDA
   else if (platform::is_gpu_place(src_place) &&
            platform::is_cpu_place(dst_place)) {
-    memory::Copy(boost::get<platform::CPUPlace>(dst_place), dst_ptr,
-                 boost::get<platform::GPUPlace>(src_place), src_ptr, size, 0);
+    auto src_gpu_place = boost::get<platform::GPUPlace>(src_place);
+    auto dst_cpu_place = boost::get<platform::CPUPlace>(dst_place);
+    auto ctx_place = ctx.GetPlace();
+    PADDLE_ENFORCE(platform::is_gpu_place(ctx_place));
+    auto ctx_gpu_place = boost::get<platform::GPUPlace>(ctx_place);
+    PADDLE_ENFORCE_EQ(src_gpu_place, ctx_gpu_place);
+    memory::Copy(
+        dst_cpu_place, dst_ptr, src_gpu_place, src_ptr, size,
+        reinterpret_cast<const platform::CUDADeviceContext&>(ctx).stream());
   } else if (platform::is_cpu_place(src_place) &&
              platform::is_gpu_place(dst_place)) {
-    memory::Copy(boost::get<platform::GPUPlace>(dst_place), dst_ptr,
-                 boost::get<platform::CPUPlace>(src_place), src_ptr, size, 0);
+    auto src_cpu_place = boost::get<platform::CPUPlace>(src_place);
+    auto dst_gpu_place = boost::get<platform::GPUPlace>(dst_place);
+    auto ctx_place = ctx.GetPlace();
+    PADDLE_ENFORCE(platform::is_gpu_place(ctx_place));
+    auto ctx_gpu_place = boost::get<platform::GPUPlace>(ctx_place);
+    PADDLE_ENFORCE_EQ(dst_gpu_place, ctx_gpu_place);
+    memory::Copy(
+        dst_gpu_place, dst_ptr, src_cpu_place, src_ptr, size,
+        reinterpret_cast<const platform::CUDADeviceContext&>(ctx).stream());
   } else if (platform::is_gpu_place(src_place) &&
              platform::is_gpu_place(dst_place)) {
-    memory::Copy(boost::get<platform::GPUPlace>(dst_place), dst_ptr,
-                 boost::get<platform::GPUPlace>(src_place), src_ptr, size, 0);
+    auto src_gpu_place = boost::get<platform::GPUPlace>(src_place);
+    auto dst_gpu_place = boost::get<platform::GPUPlace>(dst_place);
+    auto ctx_place = ctx.GetPlace();
+    PADDLE_ENFORCE(platform::is_gpu_place(ctx_place));
+    auto ctx_gpu_place = boost::get<platform::GPUPlace>(ctx_place);
+    PADDLE_ENFORCE_EQ(src_gpu_place, ctx_gpu_place);
+    memory::Copy(
+        dst_gpu_place, dst_ptr, src_gpu_place, src_ptr, size,
+        reinterpret_cast<const platform::CUDADeviceContext&>(ctx).stream());
   }
-  PADDLE_ENFORCE(cudaStreamSynchronize(0),
-                 "cudaStreamSynchronize failed in Tensor CopyFrom");
-
 #endif
 }
 
 template <typename T>
 inline void Tensor::CopyFromVector(const std::vector<T>& src,
-                                   const platform::Place& dst_place) {
+                                   const platform::DeviceContext& ctx) {
+  auto dst_place = ctx.GetPlace();
   auto src_ptr = static_cast<const void*>(src.data());
   platform::CPUPlace src_place;
   auto dst_ptr = static_cast<void*>(mutable_data<T>(dst_place));
@@ -137,12 +157,11 @@ inline void Tensor::CopyFromVector(const std::vector<T>& src,
   }
 #ifdef PADDLE_WITH_CUDA
   else if (platform::is_gpu_place(dst_place)) {
-    memory::Copy(boost::get<platform::GPUPlace>(dst_place), dst_ptr, src_place,
-                 src_ptr, size, 0);
+    memory::Copy(
+        boost::get<platform::GPUPlace>(dst_place), dst_ptr, src_place, src_ptr,
+        size,
+        reinterpret_cast<const platform::CUDADeviceContext&>(ctx).stream());
   }
-  PADDLE_ENFORCE(cudaStreamSynchronize(0),
-                 "cudaStreamSynchronize failed in Tensor CopyFromVector");
-
 #endif
 }
 

paddle/framework/tensor_test.cc

@@ -194,6 +194,7 @@ TEST(Tensor, CopyFrom) {
   {
     Tensor src_tensor;
     Tensor dst_tensor;
+    CPUDeviceContext cpu_ctx((CPUPlace()));
 
     int* src_ptr = src_tensor.mutable_data<int>(make_ddim({3, 3}), CPUPlace());
 
@@ -201,7 +202,7 @@ TEST(Tensor, CopyFrom) {
     memcpy(src_ptr, arr, 9 * sizeof(int));
 
     auto cpu_place = new paddle::platform::CPUPlace();
-    dst_tensor.CopyFrom<int>(src_tensor, *cpu_place);
+    dst_tensor.CopyFrom<int>(src_tensor, *cpu_place, cpu_ctx);
 
     const int* dst_ptr = dst_tensor.data<int>();
     ASSERT_NE(src_ptr, dst_ptr);
@@ -210,7 +211,7 @@ TEST(Tensor, CopyFrom) {
     }
 
     Tensor slice_tensor = src_tensor.Slice<int>(1, 2);
-    dst_tensor.CopyFrom<int>(slice_tensor, *cpu_place);
+    dst_tensor.CopyFrom<int>(slice_tensor, *cpu_place, cpu_ctx);
     const int* slice_ptr = slice_tensor.data<int>();
     dst_ptr = dst_tensor.data<int>();
     ASSERT_NE(dst_ptr, slice_ptr);
@@ -231,13 +232,15 @@ TEST(Tensor, CopyFrom) {
 
     // CPU Tensor to GPU Tensor
     auto gpu_place = new paddle::platform::GPUPlace(0);
-    gpu_tensor.CopyFrom<int>(src_tensor, *gpu_place);
+    CUDADeviceContext gpu_ctx(*gpu_place);
+    gpu_tensor.CopyFrom<int>(src_tensor, *gpu_place, gpu_ctx);
 
     // GPU Tensor to CPU Tensor
     auto cpu_place = new paddle::platform::CPUPlace();
-    dst_tensor.CopyFrom<int>(gpu_tensor, *cpu_place);
+    dst_tensor.CopyFrom<int>(gpu_tensor, *cpu_place, gpu_ctx);
 
-    // Compare Tensors
+    // Sync before Compare Tensors
+    gpu_ctx.Wait();
     const int* dst_ptr = dst_tensor.data<int>();
     ASSERT_NE(src_ptr, dst_ptr);
     for (size_t i = 0; i < 9; ++i) {
@@ -247,12 +250,13 @@ TEST(Tensor, CopyFrom) {
     Tensor slice_tensor = src_tensor.Slice<int>(1, 2);
 
     // CPU Slice Tensor to GPU Tensor
-    gpu_tensor.CopyFrom<int>(slice_tensor, *gpu_place);
+    gpu_tensor.CopyFrom<int>(slice_tensor, *gpu_place, gpu_ctx);
 
     // GPU Tensor to CPU Tensor
-    dst_tensor.CopyFrom<int>(gpu_tensor, *cpu_place);
+    dst_tensor.CopyFrom<int>(gpu_tensor, *cpu_place, gpu_ctx);
 
-    // Compare Slice Tensors
+    // Sync before Compare Slice Tensors
+    gpu_ctx.Wait();
     const int* slice_ptr = slice_tensor.data<int>();
     dst_ptr = dst_tensor.data<int>();
     ASSERT_NE(dst_ptr, slice_ptr);
@@ -273,7 +277,8 @@ TEST(Tensor, CopyFromVector) {
     // Copy to CPU Tensor
     cpu_tensor.Resize(make_ddim({3, 3}));
     auto cpu_place = new paddle::platform::CPUPlace();
-    cpu_tensor.CopyFromVector<int>(src_vec, *cpu_place);
+    CPUDeviceContext cpu_ctx(*cpu_place);
+    cpu_tensor.CopyFromVector<int>(src_vec, cpu_ctx);
 
     // Compare Tensors
     const int* cpu_ptr = cpu_tensor.data<int>();
@@ -285,7 +290,7 @@ TEST(Tensor, CopyFromVector) {
 
     src_vec.erase(src_vec.begin(), src_vec.begin() + 5);
     cpu_tensor.Resize(make_ddim({2, 2}));
-    cpu_tensor.CopyFromVector<int>(src_vec, *cpu_place);
+    cpu_tensor.CopyFromVector<int>(src_vec, cpu_ctx);
     cpu_ptr = cpu_tensor.data<int>();
     src_ptr = src_vec.data();
     ASSERT_NE(src_ptr, cpu_ptr);
@@ -306,16 +311,19 @@ TEST(Tensor, CopyFromVector) {
     // Copy to CPU Tensor
     cpu_tensor.Resize(make_ddim({3, 3}));
     auto cpu_place = new paddle::platform::CPUPlace();
-    cpu_tensor.CopyFromVector<int>(src_vec, *cpu_place);
+    CPUDeviceContext cpu_ctx(*cpu_place);
+    cpu_tensor.CopyFromVector<int>(src_vec, cpu_ctx);
 
     // Copy to GPUTensor
     gpu_tensor.Resize(make_ddim({3, 3}));
     auto gpu_place = new paddle::platform::GPUPlace();
-    gpu_tensor.CopyFromVector<int>(src_vec, *gpu_place);
+    CUDADeviceContext gpu_ctx(*gpu_place);
+    gpu_tensor.CopyFromVector<int>(src_vec, gpu_ctx);
     // Copy from GPU to CPU tensor for comparison
-    dst_tensor.CopyFrom<int>(gpu_tensor, *cpu_place);
+    dst_tensor.CopyFrom<int>(gpu_tensor, *cpu_place, gpu_ctx);
 
-    // Compare Tensors
+    // Sync before Compare Tensors
+    gpu_ctx.Wait();
     const int* src_ptr = src_vec.data();
     const int* cpu_ptr = cpu_tensor.data<int>();
     const int* dst_ptr = dst_tensor.data<int>();
@@ -329,11 +337,13 @@ TEST(Tensor, CopyFromVector) {
     src_vec.erase(src_vec.begin(), src_vec.begin() + 5);
 
     cpu_tensor.Resize(make_ddim({2, 2}));
-    cpu_tensor.CopyFromVector<int>(src_vec, *cpu_place);
+    cpu_tensor.CopyFromVector<int>(src_vec, cpu_ctx);
     gpu_tensor.Resize(make_ddim({2, 2}));
-    gpu_tensor.CopyFromVector<int>(src_vec, *gpu_place);
-    dst_tensor.CopyFrom<int>(gpu_tensor, *cpu_place);
+    gpu_tensor.CopyFromVector<int>(src_vec, gpu_ctx);
+    dst_tensor.CopyFrom<int>(gpu_tensor, *cpu_place, gpu_ctx);
 
+    // Sync before Compare Tensors
+    gpu_ctx.Wait();
     src_ptr = src_vec.data();
     cpu_ptr = cpu_tensor.data<int>();
     dst_ptr = dst_tensor.data<int>();

paddle/operators/feed_op.h

@@ -34,7 +34,7 @@ class FeedKernel : public framework::OpKernel<T> {
     // TODO(qijun):
     //   check tensors[col].dims() with attribute,
     //   except the first dimenson.
-    out->CopyFrom<T>(tensors[col], ctx.GetPlace());
+    out->CopyFrom<T>(tensors[col], ctx.GetPlace(), ctx.device_context());
   }
 };
 

paddle/operators/fetch_op.h

@@ -35,7 +35,8 @@ class FetchKernel : public framework::OpKernel<T> {
     PADDLE_ENFORCE_GT(tensors->size(), static_cast<size_t>(col));
     (*tensors)[col].Resize(input->dims());
     (*tensors)[col].mutable_data<T>(platform::CPUPlace());
-    (*tensors)[col].CopyFrom<T>(*input, platform::CPUPlace());
+    (*tensors)[col].CopyFrom<T>(*input, platform::CPUPlace(),
+                                ctx.device_context());
     // TODO(qijun): need to handle LodTensor later
   }
 };

paddle/operators/math/im2col_test.cc

@@ -49,10 +49,22 @@ void testIm2col() {
   memcpy(input_ptr, arr, 6 * sizeof(float));
 
   auto* place = new Place();
+  paddle::platform::DeviceContext* context;
+  if (paddle::platform::is_cpu_place(*place)) {
+    context =
+        new paddle::platform::CPUDeviceContext(paddle::platform::CPUPlace());
+  } else {
+#ifdef PADDLE_WITH_CUDA
+    context =
+        new paddle::platform::CUDADeviceContext(paddle::platform::GPUPlace());
+#else
+    PADDLE_THROW("no GPU support");
+#endif  // PADDLE_ONLY_CPU
+  }
   if (paddle::platform::is_cpu_place(*place)) {
     input = input_tmp;
   } else {
-    input.CopyFrom<float>(input_tmp, *place);
+    input.CopyFrom<float>(input_tmp, *place, *context);
   }
   output_cfo.mutable_data<float>(
       {1, filter_size, filter_size, output_height, output_width}, *place);
@@ -66,18 +78,6 @@ void testIm2col() {
       paddle::operators::math::ColFormat::kOCF, Place, float>
       im2col_ocf;
 
-  paddle::platform::DeviceContext* context;
-  if (paddle::platform::is_cpu_place(*place)) {
-    context =
-        new paddle::platform::CPUDeviceContext(paddle::platform::CPUPlace());
-  } else {
-#ifdef PADDLE_WITH_CUDA
-    context =
-        new paddle::platform::CUDADeviceContext(paddle::platform::GPUPlace());
-#else
-    PADDLE_THROW("no GPU support");
-#endif  // PADDLE_ONLY_CPU
-  }
   im2col(*context, input, output_cfo, stride, stride, padding, padding);
   im2col_ocf(*context, input, output_ocf, stride, stride, padding, padding);
 
@@ -85,7 +85,8 @@ void testIm2col() {
   if (paddle::platform::is_cpu_place(*place)) {
     out_cfo_ptr = output_cfo.data<float>();
   } else {
-    output_tmp.CopyFrom<float>(output_cfo, paddle::platform::CPUPlace());
+    output_tmp.CopyFrom<float>(output_cfo, paddle::platform::CPUPlace(),
+                               *context);
     out_cfo_ptr = output_tmp.data<float>();
   }
   EXPECT_EQ(out_cfo_ptr[0], 0);
@@ -101,7 +102,8 @@ void testIm2col() {
   if (paddle::platform::is_cpu_place(*place)) {
     out_ocf_ptr = output_ocf.data<float>();
   } else {
-    output_tmp.CopyFrom<float>(output_ocf, paddle::platform::CPUPlace());
+    output_tmp.CopyFrom<float>(output_ocf, paddle::platform::CPUPlace(),
+                               *context);
     out_ocf_ptr = output_tmp.data<float>();
   }
   EXPECT_EQ(out_ocf_ptr[0], 0);

paddle/operators/math/math_function_test.cc

@@ -17,17 +17,18 @@ TEST(math_function, notrans_mul_trans) {
   auto* gpu_place = new paddle::platform::GPUPlace(0);
   paddle::platform::CUDADeviceContext context(*gpu_place);
 
-  input1_gpu.CopyFrom<float>(input1, *gpu_place);
-  input2_gpu.CopyFrom<float>(input1, *gpu_place);
+  input1_gpu.CopyFrom<float>(input1, *gpu_place, context);
+  input2_gpu.CopyFrom<float>(input1, *gpu_place, context);
 
   out_gpu.mutable_data<float>({2, 2}, *gpu_place);
 
   paddle::operators::math::matmul<paddle::platform::GPUPlace, float>(
       context, input1_gpu, false, input2_gpu, true, 1, &out_gpu, 0);
 
-  out.CopyFrom<float>(out_gpu, *cpu_place);
+  out.CopyFrom<float>(out_gpu, *cpu_place, context);
 
   float* out_ptr = out.data<float>();
+  context.Wait();
   EXPECT_EQ(out_ptr[0], 5);
   EXPECT_EQ(out_ptr[1], 14);
   EXPECT_EQ(out_ptr[2], 14);
@@ -50,17 +51,18 @@ TEST(math_function, trans_mul_notrans) {
   auto* gpu_place = new paddle::platform::GPUPlace(0);
   paddle::platform::CUDADeviceContext context(*gpu_place);
 
-  input1_gpu.CopyFrom<float>(input1, *gpu_place);
-  input2_gpu.CopyFrom<float>(input1, *gpu_place);
+  input1_gpu.CopyFrom<float>(input1, *gpu_place, context);
+  input2_gpu.CopyFrom<float>(input1, *gpu_place, context);
 
   out_gpu.mutable_data<float>({3, 3}, *gpu_place);
 
   paddle::operators::math::matmul<paddle::platform::GPUPlace, float>(
       context, input1_gpu, true, input2_gpu, false, 1, &out_gpu, 0);
 
-  out.CopyFrom<float>(out_gpu, *cpu_place);
+  out.CopyFrom<float>(out_gpu, *cpu_place, context);
 
   float* out_ptr = out.data<float>();
+  context.Wait();
   EXPECT_EQ(out_ptr[0], 9);
   EXPECT_EQ(out_ptr[1], 12);
   EXPECT_EQ(out_ptr[2], 15);
@@ -98,9 +100,9 @@ TEST(math_function, gemm_notrans_cublas) {
   auto* gpu_place = new paddle::platform::GPUPlace(0);
   paddle::platform::CUDADeviceContext context(*gpu_place);
 
-  input1_gpu.CopyFrom<float>(input1, *gpu_place);
-  input2_gpu.CopyFrom<float>(input2, *gpu_place);
-  input3_gpu.CopyFrom<float>(input3, *gpu_place);
+  input1_gpu.CopyFrom<float>(input1, *gpu_place, context);
+  input2_gpu.CopyFrom<float>(input2, *gpu_place, context);
+  input3_gpu.CopyFrom<float>(input3, *gpu_place, context);
   float* a = input1_gpu.data<float>();
   float* b = input2_gpu.data<float>();
   float* c = input3_gpu.mutable_data<float>(*gpu_place);
@@ -108,7 +110,7 @@ TEST(math_function, gemm_notrans_cublas) {
   paddle::operators::math::gemm<paddle::platform::GPUPlace, float>(
       context, false, false, m, n, k, 1, a, 3, b + 1, 4, 1, c + 1, 4);
 
-  input3.CopyFrom<float>(input3_gpu, *cpu_place);
+  input3.CopyFrom<float>(input3_gpu, *cpu_place, context);
 
   // numpy code:
   // a = np.arange(6).reshape(2, 3)
@@ -116,6 +118,7 @@ TEST(math_function, gemm_notrans_cublas) {
   // c = np.arange(8).reshape(2, 4)[:, 1:]
   // out = np.arange(8).reshape(2, 4)
   // out[:, 1:] = np.dot(a, b) + c
+  context.Wait();
   EXPECT_EQ(input3_ptr[0], 0);
   EXPECT_EQ(input3_ptr[1], 24);
   EXPECT_EQ(input3_ptr[2], 28);
@@ -152,9 +155,9 @@ TEST(math_function, gemm_trans_cublas) {
   auto* gpu_place = new paddle::platform::GPUPlace(0);
   paddle::platform::CUDADeviceContext context(*gpu_place);
 
-  input1_gpu.CopyFrom<float>(input1, *gpu_place);
-  input2_gpu.CopyFrom<float>(input2, *gpu_place);
-  input3_gpu.CopyFrom<float>(input3, *gpu_place);
+  input1_gpu.CopyFrom<float>(input1, *gpu_place, context);
+  input2_gpu.CopyFrom<float>(input2, *gpu_place, context);
+  input3_gpu.CopyFrom<float>(input3, *gpu_place, context);
   float* a = input1_gpu.data<float>();
   float* b = input2_gpu.data<float>();
   float* c = input3_gpu.mutable_data<float>(*gpu_place);
@@ -162,7 +165,8 @@ TEST(math_function, gemm_trans_cublas) {
   paddle::operators::math::gemm<paddle::platform::GPUPlace, float>(
       context, false, true, m, n, k, 1, a, 3, b + 3, 3, 1, c + 1, 4);
 
-  input3.CopyFrom<float>(input3_gpu, *cpu_place);
+  input3.CopyFrom<float>(input3_gpu, *cpu_place, context);
+  context.Wait();
 
   EXPECT_EQ(input3_ptr[0], 0);
   EXPECT_EQ(input3_ptr[1], 24);

paddle/operators/multiplex_op.cu

@@ -33,7 +33,8 @@ class MultiplexGPUKernel : public framework::OpKernel<T> {
     auto cols = ins[0]->numel() / rows;
     // copy index to cpu
     Tensor index_t_cpu;
-    index_t_cpu.CopyFrom<int32_t>(*ids, platform::CPUPlace());
+    index_t_cpu.CopyFrom<int32_t>(*ids, platform::CPUPlace(),
+                                  ctx.device_context());
     auto* index = index_t_cpu.data<int32_t>();
     auto stream = reinterpret_cast<const platform::CUDADeviceContext&>(
                       ctx.device_context())
@@ -70,7 +71,8 @@ class MultiplexGradGPUKernel : public framework::OpKernel<T> {
     auto cols = ins[0]->numel() / rows;
     // copy index to cpu
     Tensor index_t_cpu;
-    index_t_cpu.CopyFrom<int32_t>(*ids, platform::CPUPlace());
+    index_t_cpu.CopyFrom<int32_t>(*ids, platform::CPUPlace(),
+                                  ctx.device_context());
     auto* index = index_t_cpu.data<int32_t>();
 
     auto stream = reinterpret_cast<const platform::CUDADeviceContext&>(

paddle/operators/recurrent_op.cc

@@ -46,7 +46,7 @@ void RecurrentAlgorithm::Run(const Scope& scope,
     }
     (*stepnet_)->Run(*step_scopes[step_id], dev_ctx);
   }
-  rnn::ConcatOutputs(step_scopes, arg_->outlinks, seq_len);
+  rnn::ConcatOutputs(step_scopes, arg_->outlinks, seq_len, dev_ctx);
 }
 
 void RecurrentAlgorithm::CreateScopes(const Scope& scope,
@@ -151,12 +151,12 @@ void RecurrentGradientAlgorithm::Run(
   auto& step_scopes = GetStepScopes(scope);
   rnn::SegmentInputs(step_scopes, arg_->inlinks, seq_len);
   for (int step_id = seq_len - 1; step_id >= 0; --step_id) {
-    if (step_id != seq_len - 1) {
+    if (static_cast<size_t>(step_id) != seq_len - 1) {
       rnn::LinkMemories(step_scopes, arg_->memories, step_id, 1);
     }
     (*stepnet_)->Run(*step_scopes[step_id], dev_ctx);
   }
-  rnn::ConcatOutputs(step_scopes, arg_->outlinks, seq_len);
+  rnn::ConcatOutputs(step_scopes, arg_->outlinks, seq_len, dev_ctx);
   LinkBootMemoryGradients(step_scopes[0]);
 }
 

paddle/operators/reshape_op.h

@@ -33,7 +33,7 @@ class ReshapeKernel : public framework::OpKernel<T> {
     std::transform(shape.begin(), shape.end(), shape_int64.begin(),
                    [](int a) { return static_cast<int64_t>(a); });
     auto out_dims = framework::make_ddim(shape_int64);
-    out->CopyFrom<T>(*in, ctx.GetPlace());
+    out->CopyFrom<T>(*in, ctx.GetPlace(), ctx.device_context());
     out->Resize(out_dims);
   }
 };
@@ -47,7 +47,7 @@ class ReshapeGradKernel : public framework::OpKernel<T> {
     d_x->mutable_data<T>(ctx.GetPlace());
 
     auto in_dims = d_x->dims();
-    d_x->CopyFrom<T>(*d_out, ctx.GetPlace());
+    d_x->CopyFrom<T>(*d_out, ctx.GetPlace(), ctx.device_context());
     d_x->Resize(in_dims);
   }
 };

paddle/operators/rnn/recurrent_op_utils.cc

@@ -51,7 +51,7 @@ void SegmentInputs(const std::vector<Scope*>& step_scopes,
 
 void ConcatOutputs(const std::vector<Scope*>& step_scopes,
                    const std::vector<std::string>& outlinks,
-                   const size_t seq_len) {
+                   const size_t seq_len, const platform::DeviceContext& ctx) {
   for (size_t i = 0; i < outlinks.size(); i++) {
     auto* output_var = step_scopes[0]->parent().FindVar(outlinks[i]);
     PADDLE_ENFORCE_NOT_NULL(output_var, "output link [%s] is not in scope.",
@@ -72,7 +72,7 @@ void ConcatOutputs(const std::vector<Scope*>& step_scopes,
       // TODO(luotao02) data type and platform::DeviceContext() should set
       // correctly
       (output->Slice<float>(j, j + 1))
-          .CopyFrom<float>(*step_output, platform::CPUPlace());
+          .CopyFrom<float>(*step_output, platform::CPUPlace(), ctx);
     }
   }
 }

paddle/operators/rnn/recurrent_op_utils.h

@@ -71,7 +71,7 @@ void SegmentInputs(const std::vector<Scope*>& step_scopes,
  */
 void ConcatOutputs(const std::vector<Scope*>& step_scopes,
                    const std::vector<std::string>& outlinks,
-                   const size_t seq_len);
+                   const size_t seq_len, const platform::DeviceContext& ctx);
 
 void LinkMemories(const std::vector<Scope*>& step_scopes,
                   const std::vector<MemoryAttr>& memories, const size_t step_id,

paddle/pybind/tensor_py.h

@@ -57,7 +57,18 @@ struct CastToPyBufferImpl<true, I, ARGS...> {
       }
       framework::Tensor dst_tensor;
       if (paddle::platform::is_gpu_place(tensor.place())) {
-        dst_tensor.CopyFrom<CUR_TYPE>(tensor, platform::CPUPlace());
+#ifdef PADDLE_WITH_CUDA
+        auto *src_ptr = static_cast<const void *>(tensor.data<CUR_TYPE>());
+        auto *dst_ptr = static_cast<void *>(dst_tensor.mutable_data<CUR_TYPE>(
+            tensor.dims(), platform::CPUPlace()));
+        // TODO(qijun): Here we use default CUDA stream to set GPU Tensor to
+        // a Python numpy array. It's better to manage CDUA stream unifiedly.
+        paddle::platform::GpuMemcpySync(dst_ptr, src_ptr,
+                                        sizeof(CUR_TYPE) * tensor.numel(),
+                                        cudaMemcpyDeviceToHost);
+#else
+        PADDLE_THROW("'GPUPlace' is not supported in CPU only device.");
+#endif
       } else if (paddle::platform::is_cpu_place(tensor.place())) {
         dst_tensor = tensor;
       }
@@ -120,6 +131,8 @@ void PyCUDATensorSetFromArray(
 
   self.Resize(framework::make_ddim(dims));
   auto *dst = self.mutable_data<T>(place);
+  // TODO(qijun): Here we use default CUDA stream to set a Python numpy
+  // array to a GPU Tensor. It's better to manage CDUA stream unifiedly.
   paddle::platform::GpuMemcpySync(dst, array.data(), sizeof(T) * array.size(),
                                   cudaMemcpyHostToDevice);
 }