Don't serialize linking for the make generator by default

pylib/gyp/generator/make.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.
 
 # Notes:
 #
 # This is all roughly based on the Makefile system used by the Linux
 # kernel, but is a non-recursive make -- we put the entire dependency
 # graph in front of make and let it figure it out.
 #
@@ skipping 263 matching lines @@
 
 CC.target ?= %(CC.target)s
 CFLAGS.target ?= $(CFLAGS)
 CXX.target ?= %(CXX.target)s
 CXXFLAGS.target ?= $(CXXFLAGS)
 LINK.target ?= %(LINK.target)s
 LDFLAGS.target ?= $(LDFLAGS)
 AR.target ?= $(AR)
 
 # C++ apps need to be linked with g++.
-#
-# Note: flock is used to seralize linking. Linking is a memory-intensive
-# process so running parallel links can often lead to thrashing.  To disable
-# the serialization, override LINK via an envrionment variable as follows:
-#
-#   export LINK=g++
-#
-# This will allow make to invoke N linker processes as specified in -jN.
-LINK ?= %(flock)s $(builddir)/linker.lock $(CXX.target)
+LINK ?= $(CXX.target)
 
 # TODO(evan): move all cross-compilation logic to gyp-time so we don't need
 # to replicate this environment fallback in make as well.
 CC.host ?= %(CC.host)s
 CFLAGS.host ?=
 CXX.host ?= %(CXX.host)s
 CXXFLAGS.host ?=
 LINK.host ?= %(LINK.host)s
 LDFLAGS.host ?=
 AR.host ?= %(AR.host)s
@@ skipping 1764 matching lines @@
     'LINK.target': GetEnvironFallback(('LINK_target', 'LINK'), '$(LINK)'),
     'CC.host':     GetEnvironFallback(('CC_host',), 'gcc'),
     'AR.host':     GetEnvironFallback(('AR_host',), 'ar'),
     'CXX.host':    GetEnvironFallback(('CXX_host',), 'g++'),
     'LINK.host':   GetEnvironFallback(('LINK_host',), '$(CXX.host)'),
   })
 
   build_file, _, _ = gyp.common.ParseQualifiedTarget(target_list[0])
   make_global_settings_array = data[build_file].get('make_global_settings', [])
   wrappers = {}
-  wrappers['LINK'] = '%s $(builddir)/linker.lock' % flock_command
   for key, value in make_global_settings_array:
     if key.endswith('_wrapper'):
       wrappers[key[:-len('_wrapper')]] = '$(abspath %s)' % value
   make_global_settings = ''
   for key, value in make_global_settings_array:
     if re.match('.*_wrapper', key):
       continue
     if value[0] != '$':
       value = '$(abspath %s)' % value
     wrapper = wrappers.get(key)
@@ skipping 124 matching lines @@
     root_makefile.write("endif\n")
   root_makefile.write('\n')
 
   if (not generator_flags.get('standalone')
       and generator_flags.get('auto_regeneration', True)):
     WriteAutoRegenerationRule(params, root_makefile, makefile_name, build_files)
 
   root_makefile.write(SHARED_FOOTER)
 
   root_makefile.close()