Add environment variable interface

paddle/memory/memory.cc

@@ -19,8 +19,13 @@ limitations under the License. */
 #include <memory>     // for unique_ptr
 #include <mutex>      // for call_once
 
+#include "glog/logging.h"
+
 #include "paddle/memory/detail/buddy_allocator.h"
 #include "paddle/memory/detail/system_allocator.h"
+#include "paddle/platform/gpu_info.h"
+
+DECLARE_double(fraction_of_gpu_memory_to_use);
 
 namespace paddle {
 namespace memory {
@@ -80,6 +85,11 @@ BuddyAllocator* GetGPUBuddyAllocator(int gpu_id) {
                                                  platform::GpuMinChunkSize(),
                                                  platform::GpuMaxChunkSize()));
     }
+    VLOG(3) << "\n\nNOTE: each GPU device use "
+            << FLAGS_fraction_of_gpu_memory_to_use * 100 << "% of GPU memory.\n"
+            << "You can set environment variable '"
+            << platform::kEnvFractionGpuMemoryToUse
+            << "' to change the fraction of GPU usage.\n\n";
   });
 
   platform::SetDeviceId(gpu_id);

paddle/memory/memory.h

@@ -14,7 +14,6 @@ limitations under the License. */
 
 #pragma once
 
-#include "paddle/platform/gpu_info.h"
 #include "paddle/platform/place.h"
 
 namespace paddle {

paddle/platform/CMakeLists.txt

@@ -1,14 +1,15 @@
 cc_library(cpu_info SRCS cpu_info.cc DEPS gflags glog)
 cc_test(cpu_info_test SRCS cpu_info_test.cc DEPS cpu_info)
 
-nv_library(gpu_info SRCS gpu_info.cc DEPS gflags)
+nv_library(gpu_info SRCS gpu_info.cc DEPS gflags glog)
 
 cc_library(place SRCS place.cc)
 cc_test(place_test SRCS place_test.cc DEPS place glog gflags)
 
 add_subdirectory(dynload)
 
 cc_test(enforce_test SRCS enforce_test.cc DEPS stringpiece)
+cc_test(environment_test SRCS environment_test.cc DEPS stringpiece)
 
 IF(WITH_GPU)
     set(GPU_CTX_DEPS dynload_cuda dynamic_loader)

paddle/platform/environment.h

@@ -0,0 +1,60 @@
+/* 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
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <vector>
+
+#include "paddle/platform/enforce.h"
+#include "paddle/string/piece.h"
+
+extern char** environ;  // for environment variables
+
+namespace paddle {
+namespace platform {
+
+inline void SetEnvVariable(const std::string& name, const std::string& value) {
+  PADDLE_ENFORCE_NE(setenv(name.c_str(), value.c_str(), 1), -1,
+                    "Failed to set environment variable %s=%s", name, value);
+}
+
+inline void UnsetEnvVariable(const std::string& name) {
+  PADDLE_ENFORCE_NE(unsetenv(name.c_str()), -1,
+                    "Failed to unset environment variable %s", name);
+}
+
+inline bool IsEnvVarDefined(const std::string& name) {
+  return std::getenv(name.c_str()) != nullptr;
+}
+
+inline std::string GetEnvValue(const std::string& name) {
+  PADDLE_ENFORCE(IsEnvVarDefined(name),
+                 "Tried to access undefined environment variable %s", name);
+  return std::getenv(name.c_str());
+}
+
+inline std::vector<std::string> GetAllEnvVariables() {
+  std::vector<std::string> vars;
+  for (auto var = environ; *var != nullptr; ++var) {
+    auto tail = string::Index(*var, "=");
+    auto name = string::SubStr(*var, 0, tail).ToString();
+    vars.push_back(name);
+  }
+  return vars;
+}
+
+}  // namespace platform
+}  // namespace paddle

paddle/platform/environment_test.cc

@@ -0,0 +1,54 @@
+/* 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/environment.h"
+
+#include "glog/logging.h"
+#include "gtest/gtest.h"
+
+TEST(ENVIRONMENT, ACCESS) {
+  namespace platform = paddle::platform;
+  namespace string = paddle::string;
+
+  platform::SetEnvVariable("PADDLE_USE_ENV", "TRUE");
+
+  EXPECT_TRUE(platform::IsEnvVarDefined("PADDLE_USE_ENV"));
+  EXPECT_EQ(platform::GetEnvValue("PADDLE_USE_ENV"), "TRUE");
+
+  platform::UnsetEnvVariable("PADDLE_USE_ENV");
+  EXPECT_FALSE(platform::IsEnvVarDefined("PADDLE_USE_ENV"));
+
+  platform::SetEnvVariable("PADDLE_USE_ENV1", "Hello ");
+  platform::SetEnvVariable("PADDLE_USE_ENV2", "World, ");
+  platform::SetEnvVariable("PADDLE_USE_ENV3", "PaddlePaddle!");
+
+  std::string env_info;
+  auto vars = platform::GetAllEnvVariables();
+  for_each(vars.begin(), vars.end(), [&](const std::string& var) {
+    env_info += platform::GetEnvValue(var);
+  });
+
+  EXPECT_TRUE(string::Contains(env_info, "Hello World, PaddlePaddle!"));
+  platform::UnsetEnvVariable("PADDLE_USE_ENV1");
+  platform::UnsetEnvVariable("PADDLE_USE_ENV2");
+  platform::UnsetEnvVariable("PADDLE_USE_ENV3");
+
+  env_info.clear();
+  vars = platform::GetAllEnvVariables();
+  for_each(vars.begin(), vars.end(), [&](const std::string& var) {
+    env_info += platform::GetEnvValue(var);
+  });
+
+  EXPECT_FALSE(string::Contains(env_info, "Hello World, PaddlePaddle!"));
+  EXPECT_FALSE(platform::IsEnvVarDefined("PADDLE_USE_ENV1"));
+  EXPECT_FALSE(platform::IsEnvVarDefined("PADDLE_USE_ENV2"));
+  EXPECT_FALSE(platform::IsEnvVarDefined("PADDLE_USE_ENV3"));
+}

paddle/platform/gpu_info.cc

@@ -13,8 +13,11 @@ 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/enforce.h"
+#include "paddle/platform/environment.h"
 
 DEFINE_double(fraction_of_gpu_memory_to_use, 0.95,
               "Default use 95% of GPU memory for PaddlePaddle,"
@@ -70,6 +73,13 @@ size_t GpuMaxChunkSize() {
 
   GpuMemoryUsage(available, total);
 
+  if (IsEnvVarDefined(kEnvFractionGpuMemoryToUse)) {
+    auto val = std::stod(GetEnvValue(kEnvFractionGpuMemoryToUse));
+    PADDLE_ENFORCE_GT(val, 0.0);
+    PADDLE_ENFORCE_LE(val, 1.0);
+    FLAGS_fraction_of_gpu_memory_to_use = val;
+  }
+
   // Reserving the rest memory for page tables, etc.
   size_t reserving = (1 - FLAGS_fraction_of_gpu_memory_to_use) * total;
 

paddle/platform/gpu_info.h

@@ -18,10 +18,15 @@ limitations under the License. */
 
 #include <cuda_runtime.h>
 #include <stddef.h>
+#include <string>
 
 namespace paddle {
 namespace platform {
 
+//! Environment variable: fraction of GPU memory to use on each device.
+const std::string kEnvFractionGpuMemoryToUse =
+    "PADDLE_FRACTION_GPU_MEMORY_TO_USE";
+
 //! Get the total number of GPU devices in system.
 int GetDeviceCount();