posix: split linux-specific bits out of sys_info_posix

base/sys_info_freebsd.cc

+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/sys_info.h"
+
+#include "base/logging.h"
+
+namespace base {
+
+int64 SysInfo::AmountOfPhysicalMemory() {
+  int pages, page_size;
+  size_t size = sizeof(pages);
+  sysctlbyname("vm.stats.vm.v_page_count", &pages, &size, NULL, 0);
+  sysctlbyname("vm.stats.vm.v_page_size", &page_size, &size, NULL, 0);
+  if (pages == -1 || page_size == -1) {
+    NOTREACHED();
+    return 0;
+  }
+  return static_cast<int64>(pages) * page_size;
+}
+
+// static
+size_t SysInfo::MaxSharedMemorySize() {
+  size_t limit;
+  size_t size = sizeof(limit);
+  sysctlbyname("kern.ipc.shmmax", &limit, &size, NULL, 0);
+  return limit;
+}
+
+}  // namespace base