fix v2 init issue on Mac (#5808)

* fix v2 init issue on Mac

* refine the v2 init

python/paddle/v2/__init__.py

@@ -62,21 +62,15 @@ __all__ = [
 cp.begin_parse()
 
 
-def init(**kwargs):
-    import py_paddle.swig_paddle as api
-    args = []
-    args_dict = {}
-    # NOTE: append arguments if they are in ENV
-    for ek, ev in os.environ.iteritems():
-        if ek.startswith("PADDLE_INIT_"):
-            args_dict[ek.replace("PADDLE_INIT_", "").lower()] = str(ev)
+def set_omp_mkl_env_vars(trainer_count):
+    '''Auto set CPU environment if have not set before.
+       export KMP_AFFINITY, OMP_DYNAMIC according to the Hyper Threading status.
+       export OMP_NUM_THREADS, MKL_NUM_THREADS according to trainer_count.
+    '''
+    import platform
+    if not platform.system() in ['Linux', 'Darwin']:
+        return
 
-    args_dict.update(kwargs)
-    # NOTE: overwrite arguments from ENV if it is in kwargs
-    for key in args_dict.keys():
-        args.append('--%s=%s' % (key, str(args_dict[key])))
-
-    # auto set cpu environment
     def set_env(key, value):
         '''If the key has not been set in the environment, set it with value.'''
         assert isinstance(key, str)
@@ -85,22 +79,59 @@ def init(**kwargs):
         if envset is None:
             os.environ[key] = value
 
-    ht = os.popen("lscpu |grep \"per core\"|awk -F':' '{print $2}'|xargs")
-    ht = int(ht.read())
-    if ht == 1:  # ht is off
-        set_env("OMP_DYNAMIC", "false")
-        set_env("KMP_AFFINITY", "granularity=fine,compact,0,0")
-    else:
+    def num_physical_cores():
+        '''Get the number of physical cores'''
+        if platform.system() == "Linux":
+            num_sockets = int(
+                os.popen("lscpu |grep \"Socket\" |awk -F':' '{print $2}'|xargs")
+                .read())
+            num_cores_per_socket = int(
+                os.popen(
+                    "lscpu |grep \"per socket\" |awk -F':' '{print $2}'|xargs")
+                .read())
+            return num_sockets * num_cores_per_socket
+        else:
+            cmds = {"Darwin": "sysctl hw.physicalcpu"}
+            return int(os.popen(cmds.get(platform.system(), "expr 1")).read())
+
+    def num_logical_processors():
+        '''Get the number of logical processors'''
+        cmds = {
+            "Linux": "grep \"processor\" /proc/cpuinfo|sort -u|wc -l",
+            "Darwin": "sysctl hw.logicalcpu"
+        }
+        return int(os.popen(cmds.get(platform.system(), "expr 1")).read())
+
+    num_cores = num_physical_cores()
+    num_processors = num_logical_processors()
+    if num_processors > num_cores:  # Hyper Threading is enabled
         set_env("OMP_DYNAMIC", "true")
         set_env("KMP_AFFINITY", "granularity=fine,compact,1,0")
-    processors = os.popen("grep \"processor\" /proc/cpuinfo|sort -u|wc -l")
-    processors = int(processors.read())
-    trainers = kwargs.get('trainer_count', 1)
-    threads = processors / trainers
+    else:
+        set_env("OMP_DYNAMIC", "false")
+        set_env("KMP_AFFINITY", "granularity=fine,compact,0,0")
+    threads = num_processors / trainer_count
     threads = '1' if threads < 1 else str(threads)
     set_env("OMP_NUM_THREADS", threads)
     set_env("MKL_NUM_THREADS", threads)
 
+
+def init(**kwargs):
+    import py_paddle.swig_paddle as api
+    args = []
+    args_dict = {}
+    # NOTE: append arguments if they are in ENV
+    for ek, ev in os.environ.iteritems():
+        if ek.startswith("PADDLE_INIT_"):
+            args_dict[ek.replace("PADDLE_INIT_", "").lower()] = str(ev)
+
+    args_dict.update(kwargs)
+    # NOTE: overwrite arguments from ENV if it is in kwargs
+    for key in args_dict.keys():
+        args.append('--%s=%s' % (key, str(args_dict[key])))
+
+    set_omp_mkl_env_vars(kwargs.get('trainer_count', 1))
+
     if 'use_gpu' in kwargs:
         cp.g_command_config_args['use_gpu'] = kwargs['use_gpu']
     if 'use_mkldnn' in kwargs: