set default cpu place for tensor alloc

paddle/framework/tensor.h

@@ -19,6 +19,7 @@ limitations under the License. */
 #include <memory>
 #include <typeindex>
 #include "paddle/framework/ddim.h"
+#include "paddle/memory/memcpy.h"
 #include "paddle/memory/memory.h"
 #include "paddle/platform/enforce.h"
 #include "paddle/platform/place.h"
@@ -104,15 +105,21 @@ class Tensor {
 
   template <typename T>
   void CopyFrom(const Tensor& src, platform::Place dst_place) {
-    PADDLE_ENFORCE(platform::is_cpu_place(src.holder_->place()) &&
-                       platform::is_cpu_place(dst_place),
-                   "Tensor::CopyFrom only support CPU now.");
-    src.EnforceSufficientMemory<T>();
+    PADDLE_ENFORCE(platform::is_cpu_place(dst_place),
+                   "Tensor::CopyFrom only support dst CPU now.");
     size_t size = product(src.dims_) * sizeof(T);
     Resize(src.dims());
     const void* src_ptr = static_cast<const void*>(src.data<T>());
     void* dst_ptr = static_cast<void*>(mutable_data<T>(dst_place));
-    memcpy(dst_ptr, src_ptr, size);
+    if (paddle::platform::is_cpu_place(holder_->place())) {
+      std::memcpy(dst_ptr, src_ptr, size);
+    } else if (paddle::platform::is_gpu_place(holder_->place())) {
+#ifdef PADDLE_ONLY_CPU
+      PADDLE_THROW("'GPUPlace' is not supported in CPU only device.");
+#else
+      GpuMemcpySync(dst_ptr, src_ptr, size, cudaMemcpyDeviceToHost);
+#endif
+    }
   }
 
   template <typename T>

paddle/pybind/pybind.cc

@@ -66,10 +66,18 @@ PYBIND11_PLUGIN(core) {
            [](pd::Tensor& self, paddle::platform::Place& place) {
              self.mutable_data<float>(place);
            })
+      .def("alloc_float",
+           [](pd::Tensor& self) {
+             self.mutable_data<float>(paddle::platform::CPUPlace());
+           })
       .def("alloc_int",
            [](pd::Tensor& self, paddle::platform::Place& place) {
              self.mutable_data<int>(place);
            })
+      .def("alloc_int",
+           [](pd::Tensor& self) {
+             self.mutable_data<int>(paddle::platform::CPUPlace());
+           })
       .def("set", paddle::pybind::PyTensorSetFromArray<float>)
       .def("set", paddle::pybind::PyTensorSetFromArray<int>)
       .def("shape",

paddle/pybind/tensor_bind.h

@@ -57,11 +57,17 @@ struct CastToPyBufferImpl<true, I, ARGS...> {
         strides[i - 1] = sizeof(CUR_TYPE) * prod;
         prod *= dims_outside[i - 1];
       }
+      Tensor dst_tensor;
+      if (paddle::platform::is_gpu_place(tensor.holder_->place())) {
+        dst_tensor.CopyFrom(tensor, platform::CPUPlace());
+      } else if (paddle::platform::is_gpu_place(tensor.holder_->place())) {
+        dst_tensor = tensor;
+      }
       return py::buffer_info(
-          tensor.mutable_data<CUR_TYPE>(tensor.holder_->place()),
+          dst_tensor.mutable_data<CUR_TYPE>(dst_tensor.holder_->place()),
           sizeof(CUR_TYPE),
           py::format_descriptor<CUR_TYPE>::format(),
-          (size_t)framework::arity(tensor.dims()),
+          (size_t)framework::arity(dst_tensor.dims()),
           dims_outside,
           strides);
     } else {