Allow args to be optional in deepspeed.initialize (#825)

deepspeed/__init__.py

@@ -49,8 +49,8 @@ def _parse_version(version_str):
 sys.modules['deepspeed.pt.loss_scaler'] = deepspeed.runtime.fp16.loss_scaler
 
 
-def initialize(args,
-               model,
+def initialize(args=None,
+               model=None,
                optimizer=None,
                model_parameters=None,
                training_data=None,
@@ -62,8 +62,7 @@ def initialize(args,
     """Initialize the DeepSpeed Engine.
 
     Arguments:
-        args: a dictionary containing local_rank and deepspeed_config
-            file location
+        args: an object containing local_rank and deepspeed_config fields. This is optional if `config_params` is passed.
 
         model: Required: nn.module class before apply any wrappers
 
@@ -88,6 +87,9 @@ def initialize(args,
             mini-batch of Tensor(s).  Used when using batched loading from a
             map-style dataset.
 
+        config_params: Optional: Instead of requiring args.deepspeed_config you can pass your deepspeed config
+            as a dictionary instead.
+
     Returns:
         A tuple of ``engine``, ``optimizer``, ``training_dataloader``, ``lr_scheduler``
 
@@ -108,6 +110,8 @@ def initialize(args,
         __git_branch__),
              ranks=[0])
 
+    assert model is not None, "deepspeed.initialize requires a model"
+
     if not isinstance(model, PipelineModule):
         engine = DeepSpeedEngine(args=args,
                                  model=model,

deepspeed/runtime/engine.py

@@ -495,9 +495,10 @@ def _configure_with_arguments(self, args, mpu):
         # After the distributed backend is initialized we are guaranteed the LOCAL_RANK
         # environment variable is set. We must align args.local_rank to this value for
         # backwards compatability with scripts relying on [args|self].local_rank containing
-        # the correct local rank info.
-        args.local_rank = int(os.environ['LOCAL_RANK'])
-        self.local_rank = args.local_rank
+        # the correct local rank info. _do_args_sanity_check will ensure this is the case.
+        self.local_rank = int(os.environ['LOCAL_RANK'])
+        if hasattr(args, 'local_rank'):
+            args.local_rank = self.local_rank
 
         config_file = args.deepspeed_config if hasattr(args,
                                                        'deepspeed_config') else None
@@ -513,15 +514,14 @@ def _do_args_sanity_check(self, args):
                 assert args.deepspeed_config is None, "Not sure how to proceed, we were given both a deepscale_config and deepspeed_config"
             args.deepspeed_config = args.deepscale_config
 
-        local_rank_err = "DeepSpeed requires a command line parameter of --local_rank [int] and/or setting the LOCAL_RANK environment variable."
-        if hasattr(args, 'local_rank'):
-            assert type(args.local_rank) == int, local_rank_err
-            if "LOCAL_RANK" in os.environ and args.local_rank >= 0:
-                env_local_rank = int(os.environ.get("LOCAL_RANK", -1))
+        assert "LOCAL_RANK" in os.environ, "DeepSpeed requires the LOCAL_RANK environment variable, it is set by the deepspeed launcher, " \
+            "deepspeed.init_distributed, or the torch.distributed launcher. If using a different launcher please ensure LOCAL_RANK is set prior to initializing deepspeed."
+        if hasattr(args, 'local_rank') and args.local_rank != None:
+            assert isinstance(args.local_rank, int), f"args.local_rank of {args.local_rank} is an unknown type {type(args.local_rank)}"
+            if args.local_rank >= 0:
+                env_local_rank = int(os.environ.get("LOCAL_RANK"))
                 assert env_local_rank == args.local_rank, \
                     f"Mismatch in local rank setting, args.local_rank={args.local_rank} but env['LOCAL_RANK']={env_local_rank}."
-        else:
-            assert "LOCAL_RANK" in os.environ, local_rank_err
 
         if self.config_params is None:
             assert hasattr(args, 'deepspeed_config') and args.deepspeed_config is not None, \

tests/unit/test_config.py

@@ -226,3 +226,83 @@ def _helper():
                 model.step()
 
     _helper()
+
+
+def test_none_args(tmpdir):
+    config_dict = {
+        "train_batch_size": 1,
+        "optimizer": {
+            "type": "Adam",
+            "params": {
+                "lr": 0.00015
+            }
+        },
+        "fp16": {
+            "enabled": True
+        }
+    }
+
+    @distributed_test(world_size=1)
+    def _helper():
+        model = SimpleModel(hidden_dim=10)
+        model, _, _, _ = deepspeed.initialize(args=None, model=model, config_params=config_dict)
+        data_loader = random_dataloader(model=model,
+                                        total_samples=5,
+                                        hidden_dim=10,
+                                        device=model.device)
+        for n, batch in enumerate(data_loader):
+            loss = model(batch[0], batch[1])
+
+    _helper()
+
+
+def test_no_args(tmpdir):
+    config_dict = {
+        "train_batch_size": 1,
+        "optimizer": {
+            "type": "Adam",
+            "params": {
+                "lr": 0.00015
+            }
+        },
+        "fp16": {
+            "enabled": True
+        }
+    }
+
+    @distributed_test(world_size=1)
+    def _helper():
+        model = SimpleModel(hidden_dim=10)
+        model, _, _, _ = deepspeed.initialize(model=model, config_params=config_dict)
+        data_loader = random_dataloader(model=model,
+                                        total_samples=5,
+                                        hidden_dim=10,
+                                        device=model.device)
+        for n, batch in enumerate(data_loader):
+            loss = model(batch[0], batch[1])
+
+    _helper()
+
+
+def test_no_model(tmpdir):
+    config_dict = {
+        "train_batch_size": 1,
+        "optimizer": {
+            "type": "Adam",
+            "params": {
+                "lr": 0.00015
+            }
+        },
+        "fp16": {
+            "enabled": True
+        }
+    }
+
+    @distributed_test(world_size=1)
+    def _helper():
+        model = SimpleModel(hidden_dim=10)
+        with pytest.raises(AssertionError):
+            model, _, _, _ = deepspeed.initialize(model=None, config_params=config_dict)
+
+        with pytest.raises(AssertionError):
+            model, _, _, _ = deepspeed.initialize(model, config_params=config_dict)