merge lora on train completion

scripts/finetune.py

@@ -310,6 +310,20 @@ def train(
             model = BetterTransformer.reverse(model)
         model.save_pretrained(cfg.output_dir, safe_serialization=safe_serialization)
 
+    if cfg.adapter is not None:
+        # pylint: disable=duplicate-code
+        LOG.info("running merge of LoRA with base model")
+        model = model.merge_and_unload()
+        model.to(dtype=torch.float16)
+
+        if cfg.local_rank == 0:
+            LOG.info("saving merged model")
+            model.save_pretrained(
+                str(Path(cfg.output_dir) / "merged"),
+                safe_serialization=safe_serialization,
+            )
+            tokenizer.save_pretrained(str(Path(cfg.output_dir) / "merged"))
+
 
 if __name__ == "__main__":
     fire.Fire(train)