Reduce DefaultConcurrentLinks from phys/4GB to phys/5GB.

pylib/gyp/generator/ninja.py

 # Copyright (c) 2013 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import collections
 import copy
 import hashlib
 import json
 import multiprocessing
 import os.path
@@ skipping 1678 matching lines @@
         ("ullAvailPageFile", ctypes.c_ulonglong),
         ("ullTotalVirtual", ctypes.c_ulonglong),
         ("ullAvailVirtual", ctypes.c_ulonglong),
         ("sullAvailExtendedVirtual", ctypes.c_ulonglong),
       ]
 
     stat = MEMORYSTATUSEX()
     stat.dwLength = ctypes.sizeof(stat)
     ctypes.windll.kernel32.GlobalMemoryStatusEx(ctypes.byref(stat))
 
-    mem_limit = max(1, stat.ullTotalPhys / (4 * (2 ** 30)))  # total / 4GB
+    # VS 2015 uses 20% more working set than VS 2013 and can consume all RAM
+    # on a 64 GB machine.
+    mem_limit = max(1, stat.ullTotalPhys / (5 * (2 ** 30)))  # total / 5GB
     hard_cap = max(1, int(os.getenv('GYP_LINK_CONCURRENCY_MAX', 2**32)))
     return min(mem_limit, hard_cap)
   elif sys.platform.startswith('linux'):
     if os.path.exists("/proc/meminfo"):
       with open("/proc/meminfo") as meminfo:
         memtotal_re = re.compile(r'^MemTotal:\s*(\d*)\s*kB')
         for line in meminfo:
           match = memtotal_re.match(line)
           if not match:
             continue
@@ skipping 672 matching lines @@
           arglists.append(
               (target_list, target_dicts, data, params, config_name))
         pool.map(CallGenerateOutputForConfig, arglists)
       except KeyboardInterrupt, e:
         pool.terminate()
         raise e
     else:
       for config_name in config_names:
         GenerateOutputForConfig(target_list, target_dicts, data, params,
                                 config_name)