ENH: Add CPU info

paddle/platform/cpu_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/cpu_info.h"
+
+#ifdef __APPLE__
+#include <sys/sysctl.h>
+#include <sys/types.h>
+#else
+#include <unistd.h>
+#endif
+
+#include "gflags/gflags.h"
+#include "paddle/platform/error.h"
+
+DEFINE_double(fraction_of_cpu_memory_to_use, 1,
+              "Default use 100% of CPU memory for PaddlePaddle,"
+              "reserve the rest for page tables, etc");
+
+namespace paddle {
+namespace platform {
+
+inline size_t CpuTotalPhysicalMemory() {
+#ifdef __APPLE__
+  int mib[2];
+  mib[0] = CTL_HW;
+  mib[1] = HW_MEMSIZE;
+  int64_t size = 0;
+  size_t len = sizeof(size);
+  if (sysctl(mib, 2, &size, &len, NULL, 0) == 0) return (size_t)size;
+  return 0L;
+#else
+  long pages = sysconf(_SC_PHYS_PAGES);
+  long page_size = sysconf(_SC_PAGE_SIZE);
+  return pages * page_size;
+#endif
+}
+
+size_t CpuTotalMemory() {
+  return FLAGS_fraction_of_cpu_memory_to_use * CpuTotalPhysicalMemory();
+}
+
+}  // namespace platform
+}  // namespace paddle

paddle/platform/cpu_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
+
+#include <stddef.h>
+
+namespace paddle {
+namespace platform {
+
+//! Get the total memory on host machine.
+size_t CpuTotalMemory();
+
+}  // namespace platform
+}  // namespace paddle