Fix debug_launcher issues (#413)

* change to require_cpu only

.github/workflows/test.yml

@@ -14,7 +14,7 @@ jobs:
     - name: Install Python dependencies
       run: pip install setuptools==59.5.0; pip install -e .[test,test_trackers]
     - name: Run Tests
-      run: make test_cpu
+      run: make test
       
   test_examples:
     runs-on: ubuntu-latest

Makefile

@@ -24,12 +24,8 @@ style:
 	python utils/style_doc.py src/accelerate docs/source --max_len 119
 	
 # Run tests for the library
-test_cpu:
+test:
 	python -m pytest -s -v ./tests/ --ignore=./tests/test_examples.py
 
-test_cuda:
-	python -m pytest -s -v ./tests/ --ignore=./tests/test_examples.py --ignore=./tests/test_scheduler.py --ignore=./tests/test_cpu.py
-	python -m pytest -s -v ./tests/test_cpu.py ./tests/test_scheduler.py
-
 test_examples:
 	python -m pytest -s -v ./tests/test_examples.py

src/accelerate/test_utils/__init__.py

@@ -2,5 +2,13 @@
 # There's no way to ignore "F401 '...' imported but unused" warnings in this
 # module, but to preserve other warnings. So, don't check this module at all.
 
-from .testing import are_the_same_tensors, execute_subprocess_async, require_cuda, require_multi_gpu, require_tpu, slow
+from .testing import (
+    are_the_same_tensors,
+    execute_subprocess_async,
+    require_cpu,
+    require_cuda,
+    require_multi_gpu,
+    require_tpu,
+    slow,
+)
 from .training import RegressionDataset, RegressionModel

src/accelerate/test_utils/testing.py

@@ -56,6 +56,13 @@ def slow(test_case):
     return unittest.skipUnless(_run_slow_tests, "test is slow")(test_case)
 
 
+def require_cpu(test_case):
+    """
+    Decorator marking a test that must be only ran on the CPU. These tests are skipped when a GPU is available.
+    """
+    return unittest.skipUnless(not torch.cuda.is_available(), "test requires only a CPU")(test_case)
+
+
 def require_cuda(test_case):
     """
     Decorator marking a test that requires CUDA. These tests are skipped when there are no GPU available.

tests/test_cpu.py

@@ -15,9 +15,10 @@
 import unittest
 
 from accelerate import debug_launcher
-from accelerate.test_utils import test_script
+from accelerate.test_utils import require_cpu, test_script
 
 
+@require_cpu
 class MultiCPUTester(unittest.TestCase):
     def test_cpu(self):
         debug_launcher(test_script.main)

tests/test_scheduler.py

@@ -18,6 +18,7 @@ from functools import partial
 import torch
 
 from accelerate import Accelerator, debug_launcher
+from accelerate.test_utils import require_cpu
 
 
 def scheduler_test(num_processes=2, step_scheduler_with_optimizer=True, split_batches=False):
@@ -46,6 +47,7 @@ def scheduler_test(num_processes=2, step_scheduler_with_optimizer=True, split_ba
     ), f"Wrong lr found at second step, expected {expected_lr}, got {scheduler.get_last_lr()[0]}"
 
 
+@require_cpu
 class SchedulerTester(unittest.TestCase):
     def test_scheduler_steps_with_optimizer_single_process(self):
         debug_launcher(partial(scheduler_test, num_processes=1), num_processes=1)