Allow `resume_from_checkpoint` to handle `auto_find_batch_size` (#27568)

* Fuffill request

* Add test

* Better test

* Apply suggestions from code review
Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>
Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>

* Better test

* Better test

* MOre comments

---------
Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>
Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>

src/transformers/trainer.py

@@ -1507,6 +1507,10 @@ class Trainer:
             and not self.is_fsdp_enabled
         ):
             self._load_from_checkpoint(resume_from_checkpoint)
+            # In case of repeating the find_executable_batch_size, set `self._train_batch_size` properly
+            state = TrainerState.load_from_json(os.path.join(resume_from_checkpoint, TRAINER_STATE_NAME))
+            if state.train_batch_size is not None:
+                self._train_batch_size = state.train_batch_size
 
         # If model was re-initialized, put it on the right device and update self.model_wrapped
         if model_reloaded:
@@ -1542,6 +1546,8 @@ class Trainer:
     ):
         self.accelerator.free_memory()
         self._train_batch_size = batch_size
+        if self.args.auto_find_batch_size:
+            self.state.train_batch_size = self._train_batch_size
         logger.debug(f"Currently training with a batch size of: {self._train_batch_size}")
         # Data loader and number of training steps
         train_dataloader = self.get_train_dataloader()
@@ -1618,6 +1624,7 @@ class Trainer:
 
         self.state = TrainerState()
         self.state.is_hyper_param_search = trial is not None
+        self.state.train_batch_size = self._train_batch_size
 
         # Compute absolute values for logging, eval, and save if given as ratio
         if args.logging_steps is not None:

src/transformers/trainer_callback.py

@@ -59,6 +59,9 @@ class TrainerState:
             Run an evaluation every X steps.
         save_steps (`int`, *optional*, defaults to 500):
             Save checkpoint every X updates steps.
+        train_batch_size (`int`, *optional*):
+            The batch size for the training dataloader. Only needed when
+            `auto_find_batch_size` has been used.
         num_input_tokens_seen (`int`, *optional*, defaults to 0):
             The number of tokens seen during training (number of input tokens, not the number of prediction tokens).
         total_flos (`float`, *optional*, defaults to 0):
@@ -88,6 +91,7 @@ class TrainerState:
     logging_steps: int = 500
     eval_steps: int = 500
     save_steps: int = 500
+    train_batch_size: int = None
     num_train_epochs: int = 0
     num_input_tokens_seen: int = 0
     total_flos: float = 0

tests/trainer/test_trainer.py

@@ -38,6 +38,7 @@ from transformers import (
     AutoTokenizer,
     IntervalStrategy,
     PretrainedConfig,
+    TrainerCallback,
     TrainingArguments,
     get_polynomial_decay_schedule_with_warmup,
     is_torch_available,
@@ -1546,6 +1547,41 @@ class TrainerIntegrationTest(TestCasePlus, TrainerIntegrationCommon):
         with patch.object(sys, "argv", testargs):
             run_glue.main()
 
+    def test_auto_batch_size_with_resume_from_checkpoint(self):
+        train_dataset = RegressionDataset(length=128)
+
+        config = RegressionModelConfig(a=0, b=2)
+        model = RegressionRandomPreTrainedModel(config)
+
+        tmp_dir = self.get_auto_remove_tmp_dir()
+
+        class MockCudaOOMCallback(TrainerCallback):
+            def on_step_end(self, args, state, control, **kwargs):
+                # simulate OOM on the first step
+                if state.train_batch_size == 16:
+                    raise RuntimeError("CUDA out of memory.")
+
+        args = RegressionTrainingArguments(
+            tmp_dir,
+            do_train=True,
+            max_steps=2,
+            save_steps=1,
+            per_device_train_batch_size=16,
+            auto_find_batch_size=True,
+        )
+        trainer = Trainer(model, args, train_dataset=train_dataset, callbacks=[MockCudaOOMCallback()])
+        trainer.train()
+        # After `auto_find_batch_size` is ran we should now be at 8
+        self.assertEqual(trainer._train_batch_size, 8)
+
+        # We can then make a new Trainer
+        trainer = Trainer(model, args, train_dataset=train_dataset)
+        # Check we are at 16 to start
+        self.assertEqual(trainer._train_batch_size, 16)
+        trainer.train(resume_from_checkpoint=True)
+        # We should be back to 8 again, picking up based upon the last ran Trainer
+        self.assertEqual(trainer._train_batch_size, 8)
+
     # regression for this issue: https://github.com/huggingface/transformers/issues/12970
     def test_training_with_resume_from_checkpoint_false(self):
         train_dataset = RegressionDataset(length=128)