[Unified Checkpoint] Fix generation config save

paddlenlp/trainer/plugins/unified_checkpoint.py

@@ -360,6 +360,9 @@
             config_to_save.architectures = [model_to_save.__class__.__name__]
         if self.args.should_save:
             config_to_save.save_pretrained(save_directory)
+            # save generation config
+            if model_to_save.can_generate():
+                model_to_save.generation_config.save_pretrained(save_directory)
         paddle.device.cuda.empty_cache()
 
         if strtobool(os.getenv("FLAG_LLM_PDC", "False")) and self.args.should_save:
@@ -667,6 +670,10 @@
         config_to_save.architectures = [model_to_save.__class__.__name__]
         config_to_save.save_pretrained(output_dir)
 
+        # save generation config
+        if model_to_save.can_generate():
+            model_to_save.generation_config.save_pretrained(output_dir)
+
     def save_single_card_optimizer(self, model, optimizer, output_dir):
         """ "Save optimizer for non-distributed environment."""
         # Split into optimizer params and master weights.