ENH: Add Gpu info

paddle/platform/gpu_info.cc

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License. */
+
+#include "paddle/platform/gpu_info.h"
+#include "gflags/gflags.h"
+#include "paddle/platform/error.h"
+
+DEFINE_double(fraction_of_gpu_memory_to_use, 0.95,
+              "Default use 95% of GPU memory for PaddlePaddle,"
+              "reserve the rest for page tables, etc");
+
+namespace paddle {
+namespace platform {
+
+int GpuDeviceCount() {
+  int count;
+  throw_on_error(
+      cudaGetDeviceCount(&count),
+      "cudaGetDeviceCount failed in paddle::platform::GpuDeviceCount");
+  return count;
+}
+
+void GpuMemoryUsage(size_t& available, size_t& total) {
+  throw_on_error(cudaMemGetInfo(&available, &total),
+                 "cudaMemGetInfo failed in paddle::platform::GetMemoryUsage");
+}
+
+size_t GpuMaxAllocSize() {
+  size_t total = 0;
+  size_t available = 0;
+
+  GpuMemoryUsage(available, total);
+
+  return total * FLAGS_fraction_of_gpu_memory_to_use;
+}
+
+}  // namespace platform
+}  // namespace paddle

paddle/platform/gpu_info.h

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License. */
+
+#pragma once
+
+#ifndef PADDLE_ONLY_CPU
+
+#include <stddef.h>
+
+namespace paddle {
+namespace platform {
+
+//! Get the total number of GPU devices in system.
+int GpuDeviceCount();
+
+//！Get the memory usage of current GPU device.
+void GpuMemoryUsage(size_t& available, size_t& total);
+
+//! Get the maximum allocation size of current GPU device.
+size_t GpuMaxAllocSize();
+
+}  // namespace platform
+}  // namespace paddle
+
+#endif  // PADDLE_ONLY_CPU