If sysconfig fails, fallback to sysinfo

base/sys_info_linux.cc

 // Copyright (c) 2011 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 <limits>
+#include <sys/sysinfo.h>
 
 #include "base/files/file_util.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/sys_info_internal.h"
 
 namespace {
 
 int64 AmountOfMemory(int pages_name) {
+  DCHECK(pages_name == _SC_PHYS_PAGES || pages_name == _SC_AVPHYS_PAGES);
   long pages = sysconf(pages_name);
   long page_size = sysconf(_SC_PAGESIZE);
   if (pages == -1 || page_size == -1) {
-    NOTREACHED();
-    return 0;
+    struct sysinfo si;
+    int ret = sysinfo(&si);
+    DCHECK_EQ(ret, 0);
+    if (pages_name == _SC_PHYS_PAGES) {
+      return static_cast<int64>(si.totalram) * si.mem_unit;
+    } else {
+      // _SC_ACPHYS_PAGES
+      return static_cast<int64>(si.freeram) * si.mem_unit;
+    }
   }
   return static_cast<int64>(pages) * page_size;
 }
 
 int64 AmountOfPhysicalMemory() {
   return AmountOfMemory(_SC_PHYS_PAGES);
 }
 
 size_t MaxSharedMemorySize() {
   std::string contents;
@@ skipping 57 matching lines @@
       if (line.compare(0, strlen(kCpuModelPrefix), kCpuModelPrefix) == 0) {
         size_t pos = line.find(": ");
         return line.substr(pos + 2);
       }
     }
   }
   return std::string();
 }
 
 }  // namespace base