[Examples] fix checkpointing and casting bugs in `train_text_to_image_lora_sdxl.py` (#4632)

* fix: casting issues.

* fix checkpointing.

* tests

* fix: bugs

examples/test_examples.py

@@ -828,6 +828,87 @@ class ExamplesTestsAccelerate(unittest.TestCase):
                 {"checkpoint-4", "checkpoint-6"},
             )
 
+    def test_text_to_image_lora_sdxl_checkpointing_checkpoints_total_limit(self):
+        prompt = "a prompt"
+        pipeline_path = "hf-internal-testing/tiny-stable-diffusion-xl-pipe"
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            # Run training script with checkpointing
+            # max_train_steps == 7, checkpointing_steps == 2, checkpoints_total_limit == 2
+            # Should create checkpoints at steps 2, 4, 6
+            # with checkpoint at step 2 deleted
+
+            initial_run_args = f"""
+                examples/text_to_image/train_text_to_image_lora_sdxl.py
+                --pretrained_model_name_or_path {pipeline_path}
+                --dataset_name hf-internal-testing/dummy_image_text_data
+                --resolution 64
+                --train_batch_size 1
+                --gradient_accumulation_steps 1
+                --max_train_steps 7
+                --learning_rate 5.0e-04
+                --scale_lr
+                --lr_scheduler constant
+                --lr_warmup_steps 0
+                --output_dir {tmpdir}
+                --checkpointing_steps=2
+                --checkpoints_total_limit=2
+                """.split()
+
+            run_command(self._launch_args + initial_run_args)
+
+            pipe = DiffusionPipeline.from_pretrained(pipeline_path)
+            pipe.load_lora_weights(tmpdir)
+            pipe(prompt, num_inference_steps=2)
+
+            # check checkpoint directories exist
+            self.assertEqual(
+                {x for x in os.listdir(tmpdir) if "checkpoint" in x},
+                # checkpoint-2 should have been deleted
+                {"checkpoint-4", "checkpoint-6"},
+            )
+
+    def test_text_to_image_lora_sdxl_text_encoder_checkpointing_checkpoints_total_limit(self):
+        prompt = "a prompt"
+        pipeline_path = "hf-internal-testing/tiny-stable-diffusion-xl-pipe"
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            # Run training script with checkpointing
+            # max_train_steps == 7, checkpointing_steps == 2, checkpoints_total_limit == 2
+            # Should create checkpoints at steps 2, 4, 6
+            # with checkpoint at step 2 deleted
+
+            initial_run_args = f"""
+                examples/text_to_image/train_text_to_image_lora_sdxl.py
+                --pretrained_model_name_or_path {pipeline_path}
+                --dataset_name hf-internal-testing/dummy_image_text_data
+                --resolution 64
+                --train_batch_size 1
+                --gradient_accumulation_steps 1
+                --max_train_steps 7
+                --learning_rate 5.0e-04
+                --scale_lr
+                --lr_scheduler constant
+                --train_text_encoder
+                --lr_warmup_steps 0
+                --output_dir {tmpdir}
+                --checkpointing_steps=2
+                --checkpoints_total_limit=2
+                """.split()
+
+            run_command(self._launch_args + initial_run_args)
+
+            pipe = DiffusionPipeline.from_pretrained(pipeline_path)
+            pipe.load_lora_weights(tmpdir)
+            pipe(prompt, num_inference_steps=2)
+
+            # check checkpoint directories exist
+            self.assertEqual(
+                {x for x in os.listdir(tmpdir) if "checkpoint" in x},
+                # checkpoint-2 should have been deleted
+                {"checkpoint-4", "checkpoint-6"},
+            )
+
     def test_text_to_image_lora_checkpointing_checkpoints_total_limit_removes_multiple_checkpoints(self):
         pretrained_model_name_or_path = "hf-internal-testing/tiny-stable-diffusion-pipe"
         prompt = "a prompt"

examples/text_to_image/train_text_to_image_lora_sdxl.py

@@ -396,16 +396,6 @@ def parse_args(input_args=None):
             " flag passed with the `accelerate.launch` command. Use this argument to override the accelerate config."
         ),
     )
-    parser.add_argument(
-        "--prior_generation_precision",
-        type=str,
-        default=None,
-        choices=["no", "fp32", "fp16", "bf16"],
-        help=(
-            "Choose prior generation precision between fp32, fp16 and bf16 (bfloat16). Bf16 requires PyTorch >="
-            " 1.10.and an Nvidia Ampere GPU.  Default to  fp16 if a GPU is available else fp32."
-        ),
-    )
     parser.add_argument("--local_rank", type=int, default=-1, help="For distributed training: local_rank")
     parser.add_argument(
         "--enable_xformers_memory_efficient_attention", action="store_true", help="Whether or not to use xformers."
@@ -724,11 +714,15 @@ def main(args):
 
         lora_state_dict, network_alphas = LoraLoaderMixin.lora_state_dict(input_dir)
         LoraLoaderMixin.load_lora_into_unet(lora_state_dict, network_alphas=network_alphas, unet=unet_)
+
+        text_encoder_state_dict = {k: v for k, v in lora_state_dict.items() if "text_encoder." in k}
         LoraLoaderMixin.load_lora_into_text_encoder(
-            lora_state_dict, network_alphas=network_alphas, text_encoder=text_encoder_one_
+            text_encoder_state_dict, network_alphas=network_alphas, text_encoder=text_encoder_one_
         )
+
+        text_encoder_2_state_dict = {k: v for k, v in lora_state_dict.items() if "text_encoder_2." in k}
         LoraLoaderMixin.load_lora_into_text_encoder(
-            lora_state_dict, network_alphas=network_alphas, text_encoder=text_encoder_two_
+            text_encoder_2_state_dict, network_alphas=network_alphas, text_encoder=text_encoder_two_
         )
 
     accelerator.register_save_state_pre_hook(save_model_hook)
@@ -1002,9 +996,12 @@ def main(args):
                 continue
 
             with accelerator.accumulate(unet):
+                # Convert images to latent space
+                if args.pretrained_vae_model_name_or_path is not None:
                     pixel_values = batch["pixel_values"].to(dtype=weight_dtype)
+                else:
+                    pixel_values = batch["pixel_values"]
 
-                # Convert images to latent space
                 model_input = vae.encode(pixel_values).latent_dist.sample()
                 model_input = model_input * vae.config.scaling_factor
                 if args.pretrained_vae_model_name_or_path is None:
@@ -1147,13 +1144,6 @@ def main(args):
                     f" {args.validation_prompt}."
                 )
                 # create pipeline
-                if not args.train_text_encoder:
-                    text_encoder_one = text_encoder_cls_one.from_pretrained(
-                        args.pretrained_model_name_or_path, subfolder="text_encoder", revision=args.revision
-                    )
-                    text_encoder_two = text_encoder_cls_two.from_pretrained(
-                        args.pretrained_model_name_or_path, subfolder="text_encoder_2", revision=args.revision
-                    )
                 pipeline = StableDiffusionXLPipeline.from_pretrained(
                     args.pretrained_model_name_or_path,
                     vae=vae,