Merge branch 'no_cpu_allowed' into 'master'

optionally allow no cpu

See merge request ADLR/megatron-lm!80

megatron/initialize.py

@@ -29,9 +29,13 @@ from megatron.global_vars import set_global_variables
 
 
 def initialize_megatron(extra_args_provider=None, args_defaults={},
-                        ignore_unknown_args=False):
+                        ignore_unknown_args=False, allow_no_cuda=False):
     """Set global variables, initialize distributed, and
-    set autoresume and random seeds."""
+    set autoresume and random seeds.
+    `allow_no_cuda` should not be set unless using megatron for cpu only 
+    data processing. In general this arg should not be set unless you know 
+    what you are doing."""
+    if not allow_no_cuda:
         # Make sure cuda is available.
         assert torch.cuda.is_available(), 'Megatron requires CUDA.'