Changes in create_optimizer to support tensor parallelism with SMP (#16880)

* changes in create optimizer to support tensor parallelism with SMP

* Update src/transformers/trainer.py

Convert if check to one line.
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>
Co-authored-by: Cavdar <dcavdar@a07817b12d7e.ant.amazon.com>
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

src/transformers/trainer.py

@@ -843,16 +843,18 @@ class Trainer:
         We provide a reasonable default that works well. If you want to use something else, you can pass a tuple in the
         Trainer's init through `optimizers`, or subclass and override this method in a subclass.
         """
+        opt_model = self.model_wrapped if is_sagemaker_mp_enabled() else self.model
+
         if self.optimizer is None:
-            decay_parameters = get_parameter_names(self.model, [nn.LayerNorm])
+            decay_parameters = get_parameter_names(opt_model, [nn.LayerNorm])
             decay_parameters = [name for name in decay_parameters if "bias" not in name]
             optimizer_grouped_parameters = [
                 {
-                    "params": [p for n, p in self.model.named_parameters() if n in decay_parameters],
+                    "params": [p for n, p in opt_model.named_parameters() if n in decay_parameters],
                     "weight_decay": self.args.weight_decay,
                 },
                 {
-                    "params": [p for n, p in self.model.named_parameters() if n not in decay_parameters],
+                    "params": [p for n, p in opt_model.named_parameters() if n not in decay_parameters],
                     "weight_decay": 0.0,
                 },
             ]
@@ -872,7 +874,7 @@ class Trainer:
 
                     manager = bitsandbytes.optim.GlobalOptimManager.get_instance()
 
-                    for module in self.model.modules():
+                    for module in opt_model.modules():
                         if isinstance(module, nn.Embedding):
                             manager.register_module_override(module, "weight", {"optim_bits": 32})
                             logger.debug(f"bitsandbytes: will optimize {module} in fp32")