Fix low cpu mem usage tests (#30808)

* Fix tests

* fix udop failing test

* remove skip

* style

src/transformers/models/udop/modeling_udop.py

@@ -1297,7 +1297,7 @@ class UdopStack(UdopPreTrainedModel):
         # get weights from encoder position bias
         self.relative_bias = self._get_relative_bias(config)
 
-        # tie weights of original position bias of encoder
+    def _tie_weights(self):
         for bias in self.relative_bias.biases:
             if isinstance(bias, RelativePositionBias1D):
                 self._tie_or_clone_weights(

tests/test_modeling_common.py

@@ -21,7 +21,6 @@ import os.path
 import random
 import re
 import tempfile
-import unittest
 import warnings
 from collections import defaultdict
 from typing import Dict, List, Tuple
@@ -444,7 +443,6 @@ class ModelTesterMixin:
     @slow
     @require_accelerate
     @mark.accelerate_tests
-    @unittest.skip("Need to fix since we have a device mismatch")
     def test_save_load_low_cpu_mem_usage(self):
         config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()
         with tempfile.TemporaryDirectory() as saved_model_path:
@@ -457,7 +455,6 @@ class ModelTesterMixin:
     @slow
     @require_accelerate
     @mark.accelerate_tests
-    @unittest.skip("Need to fix since we have a device mismatch")
     def test_save_load_low_cpu_mem_usage_checkpoints(self):
         config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()
         with tempfile.TemporaryDirectory() as saved_model_path:
@@ -471,7 +468,6 @@ class ModelTesterMixin:
     @slow
     @require_accelerate
     @mark.accelerate_tests
-    @unittest.skip("Need to fix since we have a device mismatch")
     def test_save_load_low_cpu_mem_usage_no_safetensors(self):
         with tempfile.TemporaryDirectory() as saved_model_path:
             for model_class in self.all_model_classes:
@@ -482,6 +478,8 @@ class ModelTesterMixin:
                 self._check_save_load_low_cpu_mem_usage(model_class, saved_model_path)
 
     def _check_save_load_low_cpu_mem_usage(self, model_class, saved_model_path):
+        from accelerate.utils.modeling import named_module_tensors
+
         # Load the low usage and the normal models.
         model_low_usage, loading_info = model_class.from_pretrained(
             saved_model_path,
@@ -496,16 +494,13 @@ class ModelTesterMixin:
         # The low_cpu_mem_usage=True causes the model params to be initialized with device=meta, and then
         # subsequently loaded with the correct values and onto the correct device. We check if there are any
         # remaining params that were not properly loaded.
-        for name, param in model_low_usage.named_parameters():
+        for name, tensor in named_module_tensors(model_low_usage, recurse=True):
             self.assertNotEqual(
-                param.device,
+                tensor.device,
                 torch.device("meta"),
-                "Parameter '" + name + "' has not been properly loaded and has device=meta.",
+                "Tensor '" + name + "' has not been properly loaded and has device=meta.",
             )
 
-        # Tests moving the model to a device other than meta.
-        model_low_usage.to(torch_device)
-
         # Check that the parameters are equal.
         for p1, p2 in zip(model_low_usage.parameters(), model_non_low_usage.parameters()):
             self.assertEquals(p1.data.ne(p2.data).sum(), 0)