[GraphBolt][CUDA] Use better memory allocation algorithm to avoid OOM. (#7618)

tests/python/pytorch/graphbolt/test_base.py

@@ -1,3 +1,4 @@
+import os
 import re
 import unittest
 from collections.abc import Iterable, Mapping
@@ -12,6 +13,13 @@ from torch.torch_version import TorchVersion
 from . import gb_test_utils
 
 
+def test_pytorch_cuda_allocator_conf():
+    env = os.getenv("PYTORCH_CUDA_ALLOC_CONF")
+    assert env is not None
+    config_list = env.split(",")
+    assert "expandable_segments:True" in config_list
+
+
 @unittest.skipIf(F._default_context_str != "gpu", "CopyTo needs GPU to test")
 @pytest.mark.parametrize("non_blocking", [False, True])
 def test_CopyTo(non_blocking):