Add drop_last arg for data loader

src/transformers/trainer.py

@@ -240,6 +240,7 @@ class Trainer:
             batch_size=self.args.train_batch_size,
             sampler=train_sampler,
             collate_fn=self.data_collator.collate_batch,
+            drop_last=self.args.dataloader_drop_last,
         )
 
         return data_loader
@@ -264,6 +265,7 @@ class Trainer:
             sampler=sampler,
             batch_size=self.args.eval_batch_size,
             collate_fn=self.data_collator.collate_batch,
+            drop_last=self.args.dataloader_drop_last,
         )
 
         return data_loader

src/transformers/training_args.py

@@ -133,6 +133,10 @@ class TrainingArguments:
     )
     tpu_metrics_debug: bool = field(default=False, metadata={"help": "TPU: Whether to print debug metrics"})
 
+    dataloader_drop_last: bool = field(
+        default=False, metadata={"help": "Drop the last incomplete batch if it is not divisible by the batch size."}
+    )
+
     @property
     def train_batch_size(self) -> int:
         if self.per_gpu_train_batch_size: