Test for min torch version + fix import issue

.github/workflows/test.yml

@@ -11,6 +11,10 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
+        pytorch-version: [
+          latest,
+          minimum
+        ]
         test-kind: [
           test_prod,
           test_core,
@@ -43,6 +47,7 @@ jobs:
         if [[ ${{ matrix.test-kind }} = test_prod ]]; then pip install -e .[test_prod]; fi
         if [[ ${{ matrix.test-kind }} != test_prod ]]; then pip install -e .[testing,test_trackers]; fi
         if [[ ${{ matrix.test-kind }} = test_rest ]]; then pip uninstall comet_ml -y; fi
+        if [[ ${{ matrix.pytorch-version }} = minimum ]]; then pip install torch==1.6.0; fi
 
     - name: Run Tests
       run: |

src/accelerate/accelerator.py

@@ -279,9 +279,7 @@ def __init__(
         self.native_amp = False
         err = "{mode} mixed precision requires {requirement}"
         if self.state.mixed_precision == "fp16":
-            self.native_amp = is_torch_version(">=", "1.6")
-            if not self.native_amp:
-                raise ValueError(err.format(mode="fp16", requirement="PyTorch >= 1.6"))
+            self.native_amp = True
             if not torch.cuda.is_available() and not parse_flag_from_env("USE_MPS_DEVICE"):
                 raise ValueError(err.format(mode="fp16", requirement="a GPU"))
             kwargs = self.scaler_handler.to_kwargs() if self.scaler_handler is not None else {}
@@ -314,7 +312,7 @@ def __init__(
         # RNG Types
         self.rng_types = rng_types
         if self.rng_types is None:
-            self.rng_types = ["torch"] if is_torch_version("<=", "1.5.1") else ["generator"]
+            self.rng_types = ["generator"]
 
     @property
     def use_distributed(self):

src/accelerate/big_modeling.py

@@ -29,6 +29,7 @@
     load_checkpoint_in_model,
     offload_state_dict,
 )
+from .utils.versions import is_torch_version
 
 
 @contextmanager
@@ -59,6 +60,8 @@ def init_empty_weights(include_buffers: bool = False):
 
     </Tip>
     """
+    if not is_torch_version(">=", "1.9.0"):
+        raise NotImplementedError("Initializing empty weights to a meta device requires torch >= 1.9.0")
     old_register_parameter = nn.Module.register_parameter
     if include_buffers:
         old_register_buffer = nn.Module.register_buffer
@@ -114,6 +117,8 @@ def cpu_offload(
             called directly during the forward, for instance if a `dense` linear layer is registered, but at forward,
             `dense.weight` and `dense.bias` are used in some operations instead of calling `dense` directly.
     """
+    if not is_torch_version(">=", "1.9.0"):
+        raise NotImplementedError("CPU offloading requires torch >= 1.9.0")
     if execution_device is None:
         execution_device = next(iter(model.parameters())).device
     if state_dict is None:
@@ -157,6 +162,8 @@ def disk_offload(
             called directly during the forward, for instance if a `dense` linear layer is registered, but at forward,
             `dense.weight` and `dense.bias` are used in some operations instead of calling `dense` directly.
     """
+    if not is_torch_version(">=", "1.9.0"):
+        raise NotImplementedError("Disk offloading requires torch >= 1.9.0")
     if not os.path.isdir(offload_dir) or not os.path.isfile(os.path.join(offload_dir, "index.json")):
         offload_state_dict(offload_dir, model.state_dict())
     if execution_device is None:
@@ -208,6 +215,8 @@ def dispatch_model(
             called directly during the forward, for instance if a `dense` linear layer is registered, but at forward,
             `dense.weight` and `dense.bias` are used in some operations instead of calling `dense` directly.
     """
+    if not is_torch_version(">=", "1.9.0"):
+        raise NotImplementedError("Model dispatching requires torch >= 1.9.0")
     # Error early if the device map is incomplete.
     check_device_map(model, device_map)
 
@@ -304,6 +313,8 @@ def load_checkpoint_and_dispatch(
             called directly during the forward, for instance if a `dense` linear layer is registered, but at forward,
             `dense.weight` and `dense.bias` are used in some operations instead of calling `dense` directly.
     """
+    if not is_torch_version(">=", "1.9.0"):
+        raise NotImplementedError("Loading and dispatching requires torch >= 1.9.0")
     if isinstance(device_map, str) and device_map not in ["auto", "balanced", "balanced_low_0", "sequential"]:
         raise ValueError(
             "If passing a string for `device_map`, please choose 'auto', 'balanced', 'balanced_low_0' or "

src/accelerate/data_loader.py

@@ -75,11 +75,11 @@ def total_dataset_length(self):
     "timeout": 0,
     "worker_init_fn": None,
     "multiprocessing_context": None,
+    "generator": None,
 }
 
 # kwargs added after by version
 _PYTORCH_DATALOADER_ADDITIONAL_KWARGS = {
-    "1.6.0": {"generator": None},
     "1.7.0": {"prefetch_factor": 2, "persistent_workers": False},
 }
 
@@ -412,7 +412,7 @@ def __init__(self, dataset, split_batches: bool = False, _drop_last: bool = Fals
         self.split_batches = split_batches
         if is_torch_version("<", "1.8.0"):
             raise ImportError(
-                "Using `DataLoaderDispatcher` requires PyTorch 1.8.0 minimum. You have {torch.__version__}."
+                f"Using `DataLoaderDispatcher` requires PyTorch 1.8.0 minimum. You have {torch.__version__}."
             )
         if shuffle:
             torch.utils.data.graph_settings.apply_shuffle_settings(dataset, shuffle=shuffle)

src/accelerate/launchers.py

@@ -20,7 +20,7 @@
 import torch
 
 from .state import AcceleratorState
-from .utils import PrecisionType, PrepareForLaunch, is_torch_version, patch_environment
+from .utils import PrecisionType, PrepareForLaunch, patch_environment
 
 
 def notebook_launcher(function, args=(), num_processes=None, use_fp16=False, mixed_precision="no", use_port="29500"):
@@ -90,12 +90,6 @@ def notebook_launcher(function, args=(), num_processes=None, use_fp16=False, mix
 
         if num_processes > 1:
             # Multi-GPU launch
-            if is_torch_version("<", "1.5.0"):
-                raise ImportError(
-                    "Using `notebook_launcher` for distributed training on GPUs require torch >= 1.5.0, got "
-                    f"{torch.__version__}."
-                )
-
             from torch.multiprocessing import start_processes
 
             if len(AcceleratorState._shared_state) > 0:
@@ -154,12 +148,6 @@ def debug_launcher(function, args=(), num_processes=2):
         num_processes (`int`, *optional*, defaults to 2):
             The number of processes to use for training.
     """
-    if is_torch_version("<", "1.5.0"):
-        raise ImportError(
-            "Using `debug_launcher` for distributed training on GPUs require torch >= 1.5.0, got "
-            f"{torch.__version__}."
-        )
-
     from torch.multiprocessing import start_processes
 
     with tempfile.NamedTemporaryFile() as tmp_file:

src/accelerate/test_utils/__init__.py

@@ -10,6 +10,7 @@
     require_huggingface_suite,
     require_multi_gpu,
     require_single_gpu,
+    require_torch_min_version,
     require_tpu,
     skip,
     slow,

src/accelerate/test_utils/scripts/test_script.py

@@ -46,10 +46,9 @@ def rng_sync_check():
     if state.distributed_type == DistributedType.MULTI_GPU:
         synchronize_rng_states(["cuda"])
         assert are_the_same_tensors(torch.cuda.get_rng_state()), "RNG states improperly synchronized on GPU."
-    if is_torch_version(">=", "1.6.0"):
-        generator = torch.Generator()
-        synchronize_rng_states(["generator"], generator=generator)
-        assert are_the_same_tensors(generator.get_state()), "RNG states improperly synchronized in generator."
+    generator = torch.Generator()
+    synchronize_rng_states(["generator"], generator=generator)
+    assert are_the_same_tensors(generator.get_state()), "RNG states improperly synchronized in generator."
 
     if state.local_process_index == 0:
         print("All rng are properly synched.")
@@ -339,7 +338,7 @@ def main():
     if state.local_process_index == 0:
         print("\n**DataLoader integration test**")
     dl_preparation_check()
-    if state.distributed_type != DistributedType.TPU:
+    if state.distributed_type != DistributedType.TPU and is_torch_version(">=", "1.8.0"):
         central_dl_preparation_check()
 
     # Trainings are not exactly the same in DeepSpeed and CPU mode

src/accelerate/test_utils/testing.py

@@ -20,6 +20,7 @@
 import tempfile
 import unittest
 from distutils.util import strtobool
+from functools import partial
 from pathlib import Path
 from typing import List, Union
 from unittest import mock
@@ -132,6 +133,16 @@ def require_fsdp(test_case):
     return unittest.skipUnless(is_torch_version(">=", "1.12.0"), "test requires torch version >= 1.12.0")(test_case)
 
 
+def require_torch_min_version(test_case=None, version=None):
+    """
+    Decorator marking that a test requires a particular torch version to be tested. These tests are skipped when an
+    installed torch version is less than the required one.
+    """
+    if test_case is None:
+        return partial(require_torch_min_version, version=version)
+    return unittest.skipUnless(is_torch_version(">=", version), f"test requires torch version >= {version}")(test_case)
+
+
 def require_tensorboard(test_case):
     """
     Decorator marking a test that requires tensorboard installed. These tests are skipped when tensorboard isn't

tests/test_big_modeling.py

@@ -27,7 +27,7 @@
     load_checkpoint_and_dispatch,
 )
 from accelerate.hooks import remove_hook_from_submodules
-from accelerate.test_utils import require_cuda, require_multi_gpu, slow
+from accelerate.test_utils import require_cuda, require_multi_gpu, require_torch_min_version, slow
 from accelerate.utils import offload_state_dict
 from transformers import AutoModelForCausalLM, AutoTokenizer
 
@@ -79,6 +79,7 @@ def forward(self, x):
         return self.linear4(self.linear3(self.batchnorm(self.linear2(self.linear1(x)))))
 
 
+@require_torch_min_version(version="1.9.0")
 class BigModelingTester(unittest.TestCase):
     def test_init_empty_weights(self):
         # base use

tests/test_hooks.py

@@ -27,7 +27,7 @@
     remove_hook_from_module,
     remove_hook_from_submodules,
 )
-from accelerate.test_utils import require_multi_gpu
+from accelerate.test_utils import require_multi_gpu, require_torch_min_version
 
 
 class ModelForTest(nn.Module):
@@ -51,6 +51,7 @@ def post_forward(self, module, output):
         return output + 1
 
 
+@require_torch_min_version(version="1.9.0")
 class HooksModelTester(unittest.TestCase):
     def test_add_and_remove_hooks(self):
         test_model = ModelForTest()

tests/test_metrics.py

@@ -26,11 +26,13 @@
     require_huggingface_suite,
     require_multi_gpu,
     require_single_gpu,
+    require_torch_min_version,
 )
 from accelerate.utils import get_launch_prefix, patch_environment
 
 
 @require_huggingface_suite
+@require_torch_min_version(version="1.8.0")
 class MetricTester(unittest.TestCase):
     def setUp(self):
         mod_file = inspect.getfile(accelerate.test_utils)

tests/test_modeling_utils.py

@@ -21,6 +21,7 @@
 import torch.nn as nn
 
 from accelerate.test_utils import require_cuda, require_multi_gpu
+from accelerate.test_utils.testing import require_torch_min_version
 from accelerate.utils.modeling import (
     check_device_map,
     clean_device_map,
@@ -45,6 +46,7 @@ def forward(self, x):
         return self.linear2(self.batchnorm(self.linear1(x)))
 
 
+@require_torch_min_version(version="1.9.0")
 class ModelingUtilsTester(unittest.TestCase):
     def check_set_module_tensor_for_device(self, model, device1, device2):
         self.assertEqual(model.linear1.weight.device, torch.device(device1))