Device agnostic testing (#25870)

* adds agnostic decorators and availability fns

* renaming decorators and fixing imports

* updating some representative example tests
bloom, opt, and reformer for now

* wip device agnostic functions

* lru cache to device checking functions

* adds `TRANSFORMERS_TEST_DEVICE_SPEC`
if present, imports the target file and updates device to function
mappings

* comments `TRANSFORMERS_TEST_DEVICE_SPEC` code

* extra checks on device name

* `make style; make quality`

* updates default functions for agnostic calls

* applies suggestions from review

* adds `is_torch_available` guard

* Add spec file to docs, rename function dispatch names to backend_*

* add backend import to docs example for spec file

* change instances of  to

* Move register backend to before device check as per @statelesshz changes

* make style

* make opt test require fp16 to run

---------

Co-authored-by: arsalanu <arsalanu@graphcore.ai>
Co-authored-by: arsalanu <hzji210@gmail.com>

docs/source/en/testing.md

@@ -525,6 +525,25 @@ Certain devices will require an additional import after importing `torch` for th
 ```bash
 TRANSFORMERS_TEST_BACKEND="torch_npu" pytest tests/utils/test_logging.py
 ```
+Alternative backends may also require the replacement of device-specific functions. For example `torch.cuda.manual_seed` may need to be replaced with a device-specific seed setter like `torch.npu.manual_seed` to correctly set a random seed on the device. To specify a new backend with backend-specific device functions when running the test suite, create a Python device specification file in the format:
+
+```
+import torch
+import torch_npu
+# !! Further additional imports can be added here !!
+
+# Specify the device name (eg. 'cuda', 'cpu', 'npu')
+DEVICE_NAME = 'npu'
+
+# Specify device-specific backends to dispatch to.
+# If not specified, will fallback to 'default' in 'testing_utils.py`
+MANUAL_SEED_FN = torch.npu.manual_seed
+EMPTY_CACHE_FN = torch.npu.empty_cache
+DEVICE_COUNT_FN = torch.npu.device_count
+```
+This format also allows for specification of any additional imports required. To use this file to replace equivalent methods in the test suite, set the environment variable `TRANSFORMERS_TEST_DEVICE_SPEC` to the path of the spec file.
+
+Currently, only `MANUAL_SEED_FN`, `EMPTY_CACHE_FN` and `DEVICE_COUNT_FN` are supported for device-specific dispatch.
 
 
 ### Distributed training

src/transformers/testing_utils.py

@@ -32,7 +32,7 @@ import unittest
 from collections.abc import Mapping
 from io import StringIO
 from pathlib import Path
-from typing import Iterable, Iterator, List, Optional, Union
+from typing import Callable, Dict, Iterable, Iterator, List, Optional, Union
 from unittest import mock
 
 import huggingface_hub
@@ -98,8 +98,10 @@ from .utils import (
     is_timm_available,
     is_tokenizers_available,
     is_torch_available,
+    is_torch_bf16_available_on_device,
     is_torch_bf16_cpu_available,
     is_torch_bf16_gpu_available,
+    is_torch_fp16_available_on_device,
     is_torch_neuroncore_available,
     is_torch_npu_available,
     is_torch_tensorrt_fx_available,
@@ -713,6 +715,16 @@ if is_torch_available():
     # Set env var CUDA_VISIBLE_DEVICES="" to force cpu-mode
     import torch
 
+    if "TRANSFORMERS_TEST_BACKEND" in os.environ:
+        backend = os.environ["TRANSFORMERS_TEST_BACKEND"]
+        try:
+            _ = importlib.import_module(backend)
+        except ModuleNotFoundError as e:
+            raise ModuleNotFoundError(
+                f"Failed to import `TRANSFORMERS_TEST_BACKEND` '{backend}'! This should be the name of an installed module. The original error (look up to see its"
+                f" traceback):\n{e}"
+            ) from e
+
     if "TRANSFORMERS_TEST_DEVICE" in os.environ:
         torch_device = os.environ["TRANSFORMERS_TEST_DEVICE"]
         try:
@@ -730,17 +742,6 @@ if is_torch_available():
         torch_device = "xpu"
     else:
         torch_device = "cpu"
-
-    if "TRANSFORMERS_TEST_BACKEND" in os.environ:
-        backend = os.environ["TRANSFORMERS_TEST_BACKEND"]
-        try:
-            _ = importlib.import_module(backend)
-        except ModuleNotFoundError as e:
-            raise ModuleNotFoundError(
-                f"Failed to import `TRANSFORMERS_TEST_BACKEND` '{backend}'! This should be the name of an installed module. The original error (look up to see its"
-                f" traceback):\n{e}"
-            ) from e
-
 else:
     torch_device = None
 
@@ -770,6 +771,25 @@ def require_torch_gpu(test_case):
     return unittest.skipUnless(torch_device == "cuda", "test requires CUDA")(test_case)
 
 
+def require_torch_accelerator(test_case):
+    """Decorator marking a test that requires an accessible accelerator and PyTorch."""
+    return unittest.skipUnless(torch_device != "cpu", "test requires accelerator")(test_case)
+
+
+def require_torch_fp16(test_case):
+    """Decorator marking a test that requires a device that supports fp16"""
+    return unittest.skipUnless(
+        is_torch_fp16_available_on_device(torch_device), "test requires device with fp16 support"
+    )(test_case)
+
+
+def require_torch_bf16(test_case):
+    """Decorator marking a test that requires a device that supports bf16"""
+    return unittest.skipUnless(
+        is_torch_bf16_available_on_device(torch_device), "test requires device with bf16 support"
+    )(test_case)
+
+
 def require_torch_bf16_gpu(test_case):
     """Decorator marking a test that requires torch>=1.10, using Ampere GPU or newer arch with cuda>=11.0"""
     return unittest.skipUnless(
@@ -2176,3 +2196,86 @@ class HfDoctestModule(Module):
         for test in finder.find(module, module.__name__):
             if test.examples:  # skip empty doctests and cuda
                 yield DoctestItem.from_parent(self, name=test.name, runner=runner, dtest=test)
+
+
+def _device_agnostic_dispatch(device: str, dispatch_table: Dict[str, Callable], *args, **kwargs):
+    if device not in dispatch_table:
+        return dispatch_table["default"](*args, **kwargs)
+
+    fn = dispatch_table[device]
+
+    # Some device agnostic functions return values. Need to guard against `None`
+    # instead at user level.
+    if fn is None:
+        return None
+    return fn(*args, **kwargs)
+
+
+if is_torch_available():
+    # Mappings from device names to callable functions to support device agnostic
+    # testing.
+    BACKEND_MANUAL_SEED = {"cuda": torch.cuda.manual_seed, "cpu": torch.manual_seed, "default": torch.manual_seed}
+    BACKEND_EMPTY_CACHE = {"cuda": torch.cuda.empty_cache, "cpu": None, "default": None}
+    BACKEND_DEVICE_COUNT = {"cuda": torch.cuda.device_count, "cpu": lambda: 0, "default": lambda: 1}
+
+
+def backend_manual_seed(device: str, seed: int):
+    return _device_agnostic_dispatch(device, BACKEND_MANUAL_SEED, seed)
+
+
+def backend_empty_cache(device: str):
+    return _device_agnostic_dispatch(device, BACKEND_EMPTY_CACHE)
+
+
+def backend_device_count(device: str):
+    return _device_agnostic_dispatch(device, BACKEND_DEVICE_COUNT)
+
+
+if is_torch_available():
+    # If `TRANSFORMERS_TEST_DEVICE_SPEC` is enabled we need to import extra entries
+    # into device to function mappings.
+    if "TRANSFORMERS_TEST_DEVICE_SPEC" in os.environ:
+        device_spec_path = os.environ["TRANSFORMERS_TEST_DEVICE_SPEC"]
+        if not Path(device_spec_path).is_file():
+            raise ValueError(
+                f"Specified path to device spec file is not a file or not found. Received '{device_spec_path}"
+            )
+
+        # Try to strip extension for later import – also verifies we are importing a
+        # python file.
+        try:
+            import_name = device_spec_path[: device_spec_path.index(".py")]
+        except ValueError as e:
+            raise ValueError(f"Provided device spec file was not a Python file! Received '{device_spec_path}") from e
+
+        device_spec_module = importlib.import_module(import_name)
+
+        # Imported file must contain `DEVICE_NAME`. If it doesn't, terminate early.
+        try:
+            device_name = device_spec_module.DEVICE_NAME
+        except AttributeError as e:
+            raise AttributeError("Device spec file did not contain `DEVICE_NAME`") from e
+
+        if "TRANSFORMERS_TEST_DEVICE" in os.environ and torch_device != device_name:
+            msg = f"Mismatch between environment variable `TRANSFORMERS_TEST_DEVICE` '{torch_device}' and device found in spec '{device_name}'\n"
+            msg += "Either unset `TRANSFORMERS_TEST_DEVICE` or ensure it matches device spec name."
+            raise ValueError(msg)
+
+        torch_device = device_name
+
+        def update_mapping_from_spec(device_fn_dict: Dict[str, Callable], attribute_name: str):
+            try:
+                # Try to import the function directly
+                spec_fn = getattr(device_spec_module, attribute_name)
+                device_fn_dict[torch_device] = spec_fn
+            except AttributeError as e:
+                # If the function doesn't exist, and there is no default, throw an error
+                if "default" not in device_fn_dict:
+                    raise AttributeError(
+                        f"`{attribute_name}` not found in '{device_spec_path}' and no default fallback function found."
+                    ) from e
+
+        # Add one entry here for each `BACKEND_*` dictionary.
+        update_mapping_from_spec(BACKEND_MANUAL_SEED, "MANUAL_SEED_FN")
+        update_mapping_from_spec(BACKEND_EMPTY_CACHE, "EMPTY_CACHE_FN")
+        update_mapping_from_spec(BACKEND_DEVICE_COUNT, "DEVICE_COUNT_FN")

src/transformers/utils/__init__.py

@@ -166,10 +166,12 @@ from .import_utils import (
     is_tokenizers_available,
     is_torch_available,
     is_torch_bf16_available,
+    is_torch_bf16_available_on_device,
     is_torch_bf16_cpu_available,
     is_torch_bf16_gpu_available,
     is_torch_compile_available,
     is_torch_cuda_available,
+    is_torch_fp16_available_on_device,
     is_torch_fx_available,
     is_torch_fx_proxy,
     is_torch_mps_available,

src/transformers/utils/import_utils.py

@@ -351,6 +351,45 @@ def is_torch_bf16_available():
     return is_torch_bf16_gpu_available()
 
 
+@lru_cache()
+def is_torch_fp16_available_on_device(device):
+    if not is_torch_available():
+        return False
+
+    import torch
+
+    try:
+        x = torch.zeros(2, 2, dtype=torch.float16).to(device)
+        _ = x @ x
+    except:  # noqa: E722
+        # TODO: more precise exception matching, if possible.
+        # most backends should return `RuntimeError` however this is not guaranteed.
+        return False
+
+    return True
+
+
+@lru_cache()
+def is_torch_bf16_available_on_device(device):
+    if not is_torch_available():
+        return False
+
+    import torch
+
+    if device == "cuda":
+        return is_torch_bf16_gpu_available()
+
+    try:
+        x = torch.zeros(2, 2, dtype=torch.bfloat16).to(device)
+        _ = x @ x
+    except:  # noqa: E722
+        # TODO: more precise exception matching, if possible.
+        # most backends should return `RuntimeError` however this is not guaranteed.
+        return False
+
+    return True
+
+
 def is_torch_tf32_available():
     if not is_torch_available():
         return False

tests/models/bloom/test_modeling_bloom.py

@@ -18,7 +18,7 @@ import math
 import unittest
 
 from transformers import BloomConfig, is_torch_available
-from transformers.testing_utils import require_torch, require_torch_gpu, slow, torch_device
+from transformers.testing_utils import require_torch, require_torch_accelerator, slow, torch_device
 
 from ...generation.test_utils import GenerationTesterMixin
 from ...test_configuration_common import ConfigTester
@@ -401,7 +401,7 @@ class BloomModelTest(ModelTesterMixin, GenerationTesterMixin, PipelineTesterMixi
             self.assertIsNotNone(model)
 
     @slow
-    @require_torch_gpu
+    @require_torch_accelerator
     def test_simple_generation(self):
         # This test is a bit flaky. For some GPU architectures, pytorch sets by default allow_fp16_reduced_precision_reduction = True and some operations
         # do not give the same results under this configuration, especially torch.baddmm and torch.bmm. https://pytorch.org/docs/stable/notes/numerical_accuracy.html#fp16-on-mi200
@@ -440,7 +440,7 @@ class BloomModelTest(ModelTesterMixin, GenerationTesterMixin, PipelineTesterMixi
         self.assertEqual(tokenizer.decode(greedy_output[0], skip_special_tokens=True), EXPECTED_OUTPUT)
 
     @slow
-    @require_torch_gpu
+    @require_torch_accelerator
     def test_batch_generation(self):
         path_560m = "bigscience/bloom-560m"
         model = BloomForCausalLM.from_pretrained(path_560m, use_cache=True, revision="gs555750").to(torch_device)
@@ -460,7 +460,7 @@ class BloomModelTest(ModelTesterMixin, GenerationTesterMixin, PipelineTesterMixi
         )
 
     @slow
-    @require_torch_gpu
+    @require_torch_accelerator
     def test_batch_generation_padd(self):
         path_560m = "bigscience/bloom-560m"
         model = BloomForCausalLM.from_pretrained(path_560m, use_cache=True, revision="gs555750").to(torch_device)
@@ -489,7 +489,7 @@ class BloomModelTest(ModelTesterMixin, GenerationTesterMixin, PipelineTesterMixi
         )
 
     @slow
-    @require_torch_gpu
+    @require_torch_accelerator
     def test_batch_generated_text(self):
         path_560m = "bigscience/bloom-560m"
 

tests/models/codegen/test_modeling_codegen.py

@@ -19,7 +19,7 @@ import unittest
 
 from transformers import CodeGenConfig, is_torch_available
 from transformers.file_utils import cached_property
-from transformers.testing_utils import is_flaky, require_torch, slow, torch_device
+from transformers.testing_utils import backend_manual_seed, is_flaky, require_torch, slow, torch_device
 
 from ...generation.test_utils import GenerationTesterMixin
 from ...test_configuration_common import ConfigTester
@@ -498,8 +498,7 @@ class CodeGenModelLanguageGenerationTest(unittest.TestCase):
         model.to(torch_device)
 
         torch.manual_seed(0)
-        if torch_device == "cuda":
-            torch.cuda.manual_seed(0)
+        backend_manual_seed(torch_device, 0)
 
         tokenized = tokenizer("def hello_world():", return_tensors="pt", return_token_type_ids=True)
         input_ids = tokenized.input_ids.to(torch_device)

tests/models/opt/test_modeling_opt.py

@@ -22,7 +22,7 @@ import unittest
 import timeout_decorator  # noqa
 
 from transformers import OPTConfig, is_torch_available
-from transformers.testing_utils import require_torch, require_torch_gpu, slow, torch_device
+from transformers.testing_utils import require_torch, require_torch_fp16, require_torch_gpu, slow, torch_device
 
 from ...generation.test_utils import GenerationTesterMixin
 from ...test_configuration_common import ConfigTester
@@ -286,12 +286,12 @@ class OPTModelTest(ModelTesterMixin, GenerationTesterMixin, PipelineTesterMixin,
             with torch.no_grad():
                 model(**inputs)[0]
 
+    @require_torch_fp16
     def test_generate_fp16(self):
         config, input_dict = self.model_tester.prepare_config_and_inputs()
         input_ids = input_dict["input_ids"]
         attention_mask = input_ids.ne(1).to(torch_device)
         model = OPTForCausalLM(config).eval().to(torch_device)
-        if torch_device == "cuda":
         model.half()
         model.generate(input_ids, attention_mask=attention_mask)
         model.generate(num_beams=4, do_sample=True, early_stopping=False, num_return_sequences=3)

tests/models/reformer/test_modeling_reformer.py

@@ -20,6 +20,7 @@ from transformers.testing_utils import (
     require_sentencepiece,
     require_tokenizers,
     require_torch,
+    require_torch_fp16,
     require_torch_multi_gpu,
     slow,
     torch_device,
@@ -563,12 +564,12 @@ class ReformerTesterMixin:
         config_and_inputs = self.model_tester.prepare_config_and_inputs()
         self.model_tester.create_and_check_reformer_random_seed(*config_and_inputs)
 
-    @unittest.skipIf(torch_device == "cpu", "Cant do half precision")
+    @require_torch_fp16
     def test_reformer_model_fp16_forward(self):
         config_and_inputs = self.model_tester.prepare_config_and_inputs()
         self.model_tester.create_and_check_reformer_model_fp16_forward(*config_and_inputs)
 
-    @unittest.skipIf(torch_device == "cpu", "Cant do half precision")
+    @require_torch_fp16
     def test_reformer_model_fp16_generate(self):
         config_and_inputs = self.model_tester.prepare_config_and_inputs()
         self.model_tester.create_and_check_reformer_model_fp16_generate(*config_and_inputs)