[`core` / `gradient_checkpointing`] add support for old GC method (#27610)

* add support for old GC method

* add also disable

* up

* oops

src/transformers/modeling_utils.py

@@ -1876,7 +1876,18 @@ class PreTrainedModel(nn.Module, ModuleUtilsMixin, GenerationMixin, PushToHubMix
 
         gradient_checkpointing_func = functools.partial(checkpoint, **gradient_checkpointing_kwargs)
 
+        # For old GC format (transformers < 4.35.0) for models that live on the Hub
+        # we will fall back to the overwritten `_set_gradient_checkpointing` methid
+        _is_using_old_format = "value" in inspect.signature(self._set_gradient_checkpointing).parameters
+
+        if not _is_using_old_format:
             self._set_gradient_checkpointing(enable=True, gradient_checkpointing_func=gradient_checkpointing_func)
+        else:
+            self.apply(partial(self._set_gradient_checkpointing, value=True))
+            logger.warn(
+                "You are using an old version of the checkpointing format that is deprecated (We will also silently ignore `gradient_checkpointing_kwargs` in case you passed it)."
+                "Please update to the new format on your modeling file. To use the new format, you need to completely remove the definition of the method `_set_gradient_checkpointing` in your model."
+            )
 
         if getattr(self, "_hf_peft_config_loaded", False):
             # When using PEFT + gradient checkpointing + Trainer we need to make sure the input has requires_grad=True
@@ -1915,7 +1926,17 @@ class PreTrainedModel(nn.Module, ModuleUtilsMixin, GenerationMixin, PushToHubMix
         activations".
         """
         if self.supports_gradient_checkpointing:
+            # For old GC format (transformers < 4.35.0) for models that live on the Hub
+            # we will fall back to the overwritten `_set_gradient_checkpointing` methid
+            _is_using_old_format = "value" in inspect.signature(self._set_gradient_checkpointing).parameters
+            if not _is_using_old_format:
                 self._set_gradient_checkpointing(enable=False)
+            else:
+                logger.warn(
+                    "You are using an old version of the checkpointing format that is deprecated (We will also silently ignore `gradient_checkpointing_kwargs` in case you passed it)."
+                    "Please update to the new format on your modeling file. To use the new format, you need to completely remove the definition of the method `_set_gradient_checkpointing` in your model."
+                )
+                self.apply(partial(self._set_gradient_checkpointing, value=False))
 
         if getattr(self, "_hf_peft_config_loaded", False):
             self.disable_input_require_grads()