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

build/toolchain/get_concurrent_links.py

 # Copyright 2014 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.
 
 # This script computs the number of concurrent links we want to run in the build
 # as a function of machine spec. It's based on GetDefaultConcurrentLinks in GYP.
 
 import os
 import re
 import subprocess
@@ skipping 17 matching lines @@
         ("ullTotalPageFile", ctypes.c_ulonglong),
         ("ullAvailPageFile", ctypes.c_ulonglong),
         ("ullTotalVirtual", ctypes.c_ulonglong),
         ("ullAvailVirtual", ctypes.c_ulonglong),
         ("sullAvailExtendedVirtual", ctypes.c_ulonglong),
       ]
 
     stat = MEMORYSTATUSEX(dwLength=ctypes.sizeof(MEMORYSTATUSEX))
     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
           # Allow 8Gb per link on Linux because Gold is quite memory hungry
           return max(1, int(match.group(1)) / (8 * (2 ** 20)))
     return 1
   elif sys.platform == 'darwin':
     try:
       avail_bytes = int(subprocess.check_output(['sysctl', '-n', 'hw.memsize']))
       # A static library debug build of Chromium's unit_tests takes ~2.7GB, so
       # 4GB per ld process allows for some more bloat.
       return max(1, avail_bytes / (4 * (2 ** 30)))  # total / 4GB
     except Exception:
       return 1
   else:
     # TODO(scottmg): Implement this for other platforms.
     return 1
 
 print GetDefaultConcurrentLinks()