Skip IPC mempool tests on WSL (#1045)

* Skip IPC mempool tests on WSL

* Update cuda_core/tests/conftest.py

Co-authored-by: Phillip Cloud <417981+cpcloud@users.noreply.github.com>

* Update cuda_core/tests/test_ipc_mempool.py

Co-authored-by: Phillip Cloud <417981+cpcloud@users.noreply.github.com>

* Apply suggestion from @cpcloud

Co-authored-by: Phillip Cloud <417981+cpcloud@users.noreply.github.com>

* addressing feedback

* Making utils globally accessible

* working

* wip

* wip

* formatting

* removing deleted files

* removing skip helper

* wip

* feedback

* wip

* sorting imports

* Update cuda_core/tests/conftest.py

Co-authored-by: Leo Fang <leof@nvidia.com>

* Checking if CU_DEVICE_ATTRIBUTE_MEMPOOL_SUPPORTED_HANDLE_TYPES is supported to skip IPC tests on WSL

* Update cuda_python_test_helpers/__init__.py

Co-authored-by: Leo Fang <leof@nvidia.com>

* wip

* [pre-commit.ci] auto code formatting

* Creating the cuda_python_test_helpers as a package

* [pre-commit.ci] auto code formatting

* pre-commit changes

* removing cuda_python_test_helpers/__init__.py

* install cuda_python_test_helpers as editable

* do not require cuda_python_test_helpers to be pre-installed for now

* Revert "install cuda_python_test_helpers as editable"

This reverts commit baac405.

---------

Co-authored-by: Phillip Cloud <417981+cpcloud@users.noreply.github.com>
Co-authored-by: Leo Fang <leof@nvidia.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: 4 people

cuda_core/tests/conftest.py

@@ -1,15 +1,16 @@
-# SPDX-FileCopyrightText: Copyright (c) 2024 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2024-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
+import multiprocessing
+
 import helpers
+import pytest
 
 try:
     from cuda.bindings import driver
 except ImportError:
     from cuda import cuda as driver
-import multiprocessing
 
-import pytest
 from cuda.core.experimental import Device, DeviceMemoryResource, DeviceMemoryResourceOptions, _device
 from cuda.core.experimental._utils.cuda_utils import handle_return
 
@@ -85,6 +86,10 @@ def ipc_device():
     if not device.properties.handle_type_posix_file_descriptor_supported:
         pytest.skip("Device does not support IPC")
 
+    # Skip on WSL or if driver rejects IPC-enabled mempool creation on this platform/device
+    if helpers.IS_WSL or not helpers.supports_ipc_mempool(device):
+        pytest.skip("Driver rejects IPC-enabled mempool creation on this platform")
+
     return device
 
 

cuda_core/tests/helpers.py

@@ -2,6 +2,8 @@
 # SPDX-License-Identifier: Apache-2.0
 
 import os
+import pathlib
+import sys
 
 CUDA_PATH = os.environ.get("CUDA_PATH")
 CUDA_INCLUDE_PATH = None
@@ -14,3 +16,18 @@
         path = os.path.join(path, "cccl")
         if os.path.isdir(path):
             CCCL_INCLUDE_PATHS = (path,) + CCCL_INCLUDE_PATHS
+
+
+try:
+    import cuda_python_test_helpers
+except ImportError:
+    # Import shared platform helpers for tests across repos
+    sys.path.insert(0, str(pathlib.Path(__file__).resolve().parents[2] / "cuda_python_test_helpers"))
+    import cuda_python_test_helpers
+
+
+IS_WSL = cuda_python_test_helpers.IS_WSL
+supports_ipc_mempool = cuda_python_test_helpers.supports_ipc_mempool
+
+
+del cuda_python_test_helpers

cuda_core/tests/memory_ipc/test_errors.py

@@ -8,6 +8,8 @@
 from cuda.core.experimental import Buffer, Device, DeviceMemoryResource, DeviceMemoryResourceOptions
 from cuda.core.experimental._utils.cuda_utils import CUDAError
 
+from cuda_python_test_helpers import supports_ipc_mempool
+
 CHILD_TIMEOUT_SEC = 20
 NBYTES = 64
 POOL_SIZE = 2097152
@@ -18,6 +20,10 @@ class ChildErrorHarness:
     PARENT_ACTION, CHILD_ACTION, and ASSERT (see below for examples)."""
 
     def test_main(self, ipc_device, ipc_memory_resource):
+        if not supports_ipc_mempool(ipc_device):
+            import pytest
+
+            pytest.skip("Driver rejects IPC-enabled mempool creation on this platform")
         """Parent process that checks child errors."""
         # Attach fixtures to this object for convenience. These can be accessed
         # from PARENT_ACTION.

cuda_core/tests/memory_ipc/test_memory_ipc.py

@@ -6,6 +6,8 @@
 from cuda.core.experimental import Buffer, DeviceMemoryResource
 from utility import IPCBufferTestHelper
 
+from cuda_python_test_helpers import supports_ipc_mempool
+
 CHILD_TIMEOUT_SEC = 20
 NBYTES = 64
 NWORKERS = 2
@@ -14,6 +16,10 @@
 
 class TestIpcMempool:
     def test_main(self, ipc_device, ipc_memory_resource):
+        if not supports_ipc_mempool(ipc_device):
+            import pytest
+
+            pytest.skip("Driver rejects IPC-enabled mempool creation on this platform")
         """Test IPC with memory pools."""
         # Set up the IPC-enabled memory pool and share it.
         device = ipc_device
@@ -51,6 +57,10 @@ def child_main(self, device, mr, queue):
 
 class TestIPCMempoolMultiple:
     def test_main(self, ipc_device, ipc_memory_resource):
+        if not supports_ipc_mempool(ipc_device):
+            import pytest
+
+            pytest.skip("Driver rejects IPC-enabled mempool creation on this platform")
         """Test IPC with memory pools using multiple processes."""
         # Construct an IPC-enabled memory resource and share it with two children.
         device = ipc_device
@@ -99,6 +109,10 @@ def child_main(self, device, mr, idx, queue):
 
 class TestIPCSharedAllocationHandleAndBufferDescriptors:
     def test_main(self, ipc_device, ipc_memory_resource):
+        if not supports_ipc_mempool(ipc_device):
+            import pytest
+
+            pytest.skip("Driver rejects IPC-enabled mempool creation on this platform")
         """
         Demonstrate that a memory pool allocation handle can be reused for IPC
         with multiple processes. Uses buffer descriptors.

cuda_core/tests/memory_ipc/test_send_buffers.py

@@ -8,6 +8,8 @@
 from cuda.core.experimental import DeviceMemoryResource, DeviceMemoryResourceOptions
 from utility import IPCBufferTestHelper
 
+from cuda_python_test_helpers import supports_ipc_mempool
+
 CHILD_TIMEOUT_SEC = 20
 NBYTES = 64
 NMRS = 3
@@ -18,6 +20,8 @@
 @pytest.mark.parametrize("nmrs", (1, NMRS))
 def test_ipc_send_buffers(ipc_device, nmrs):
     """Test passing buffers sourced from multiple memory resources."""
+    if not supports_ipc_mempool(ipc_device):
+        pytest.skip("Driver rejects IPC-enabled mempool creation on this platform")
     # Set up several IPC-enabled memory pools.
     device = ipc_device
     options = DeviceMemoryResourceOptions(max_size=POOL_SIZE, ipc_enabled=True)

cuda_core/tests/memory_ipc/test_workerpool.py

@@ -9,6 +9,8 @@
 from cuda.core.experimental import Buffer, Device, DeviceMemoryResource, DeviceMemoryResourceOptions
 from utility import IPCBufferTestHelper
 
+from cuda_python_test_helpers import supports_ipc_mempool
+
 CHILD_TIMEOUT_SEC = 20
 NBYTES = 64
 NWORKERS = 2
@@ -28,6 +30,8 @@ class TestIpcWorkerPool:
 
     @pytest.mark.parametrize("nmrs", (1, NMRS))
     def test_main(self, ipc_device, nmrs):
+        if not supports_ipc_mempool(ipc_device):
+            pytest.skip("Driver rejects IPC-enabled mempool creation on this platform")
         device = ipc_device
         options = DeviceMemoryResourceOptions(max_size=POOL_SIZE, ipc_enabled=True)
         mrs = [DeviceMemoryResource(device, options=options) for _ in range(nmrs)]
@@ -62,6 +66,8 @@ def init_worker(mrs):
 
     @pytest.mark.parametrize("nmrs", (1, NMRS))
     def test_main(self, ipc_device, nmrs):
+        if not supports_ipc_mempool(ipc_device):
+            pytest.skip("Driver rejects IPC-enabled mempool creation on this platform")
         device = ipc_device
         options = DeviceMemoryResourceOptions(max_size=POOL_SIZE, ipc_enabled=True)
         mrs = [DeviceMemoryResource(device, options=options) for _ in range(nmrs)]
@@ -104,6 +110,8 @@ def init_worker(mrs):
 
     @pytest.mark.parametrize("nmrs", (1, NMRS))
     def test_main(self, ipc_device, nmrs):
+        if not supports_ipc_mempool(ipc_device):
+            pytest.skip("Driver rejects IPC-enabled mempool creation on this platform")
         device = ipc_device
         options = DeviceMemoryResourceOptions(max_size=POOL_SIZE, ipc_enabled=True)
         mrs = [DeviceMemoryResource(device, options=options) for _ in range(nmrs)]

cuda_core/tests/test_event.py

@@ -2,8 +2,6 @@
 # SPDX-License-Identifier: Apache-2.0
 
 import os
-import pathlib
-import platform
 import time
 
 import cuda.core.experimental
@@ -22,10 +20,7 @@
 )
 
 from conftest import skipif_need_cuda_headers
-
-
-def platform_is_wsl():
-    return platform.system() == "Linux" and "microsoft" in pathlib.Path("/proc/version").read_text().lower()
+from cuda_python_test_helpers import IS_WSL
 
 
 def test_event_init_disabled():
@@ -47,7 +42,7 @@ def test_timing_success(init_cuda):
     # We only want to exercise the __sub__ method, this test is not meant
     # to stress-test the CUDA driver or time.sleep().
     delay_ms = delay_seconds * 1000
-    if os.name == "nt" or platform_is_wsl():  # noqa: SIM108
+    if os.name == "nt" or IS_WSL:  # noqa: SIM108
         # For Python <=3.10, the Windows timer resolution is typically limited to 15.6 ms by default.
         generous_tolerance = 100
     else:

cuda_core/tests/test_memory.py

@@ -28,6 +28,8 @@
 from cuda.core.experimental._utils.cuda_utils import handle_return
 from cuda.core.experimental.utils import StridedMemoryView
 
+from cuda_python_test_helpers import supports_ipc_mempool
+
 POOL_SIZE = 2097152  # 2MB size
 
 
@@ -529,6 +531,9 @@ def test_mempool_attributes(ipc_enabled, mempool_device, property_name, expected
     if platform.system() == "Windows":
         return  # IPC not implemented for Windows
 
+    if ipc_enabled and not supports_ipc_mempool(device):
+        pytest.skip("Driver rejects IPC-enabled mempool creation on this platform")
+
     options = DeviceMemoryResourceOptions(max_size=POOL_SIZE, ipc_enabled=ipc_enabled)
     mr = DeviceMemoryResource(device, options=options)
     assert mr.is_ipc_enabled == ipc_enabled
@@ -567,6 +572,10 @@ def test_mempool_attributes(ipc_enabled, mempool_device, property_name, expected
 def test_mempool_attributes_ownership(mempool_device):
     """Ensure the attributes bundle handles references correctly."""
     device = mempool_device
+    # Skip if IPC mempool is not supported on this platform/device
+    if not supports_ipc_mempool(device):
+        pytest.skip("Driver rejects IPC-enabled mempool creation on this platform")
+
     mr = DeviceMemoryResource(device, dict(max_size=POOL_SIZE))
     attributes = mr.attributes
     mr.close()

cuda_python_test_helpers/cuda_python_test_helpers/__init__.py

@@ -0,0 +1,62 @@
+# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+import functools
+import os
+from contextlib import suppress
+from typing import Union
+
+from cuda.core.experimental._utils.cuda_utils import handle_return
+
+
+def _detect_wsl() -> bool:
+    data = ""
+    with suppress(Exception), open("/proc/sys/kernel/osrelease") as f:
+        data = f.read().lower()
+    if "microsoft" in data or "wsl" in data:
+        return True
+    return any(os.environ.get(k) for k in ("WSL_DISTRO_NAME", "WSL_INTEROP"))
+
+
+IS_WSL: bool = _detect_wsl()
+
+
+@functools.cache
+def supports_ipc_mempool(device_id: Union[int, object]) -> bool:
+    """Return True if mempool IPC via POSIX file descriptor is supported.
+
+    Uses cuDeviceGetAttribute(CU_DEVICE_ATTRIBUTE_MEMPOOL_SUPPORTED_HANDLE_TYPES)
+    to check for CU_MEM_HANDLE_TYPE_POSIX_FILE_DESCRIPTOR support. Does not
+    require an active CUDA context.
+    """
+    if _detect_wsl():
+        return False
+
+    try:
+        # Lazy import to avoid hard dependency when not running GPU tests
+        try:
+            from cuda.bindings import driver  # type: ignore
+        except Exception:
+            from cuda import cuda as driver  # type: ignore
+
+        # Initialize CUDA
+        handle_return(driver.cuInit(0))
+
+        # Resolve device id from int or Device-like object
+        dev_id = int(getattr(device_id, "device_id", device_id))
+
+        # Query supported mempool handle types bitmask
+        attr = driver.CUdevice_attribute.CU_DEVICE_ATTRIBUTE_MEMPOOL_SUPPORTED_HANDLE_TYPES
+        mask = handle_return(driver.cuDeviceGetAttribute(attr, dev_id))
+
+        # Check POSIX FD handle type support via bitmask
+        posix_fd = driver.CUmemAllocationHandleType.CU_MEM_HANDLE_TYPE_POSIX_FILE_DESCRIPTOR
+        return (int(mask) & int(posix_fd)) != 0
+    except Exception:
+        return False
+
+
+__all__ = [
+    "IS_WSL",
+    "supports_ipc_mempool",
+]

cuda_python_test_helpers/pyproject.toml

@@ -0,0 +1,25 @@
+# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+[build-system]
+requires = ["setuptools>=77.0.0"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "cuda-python-test-helpers"
+version = "0.1.0"
+description = "Shared test helpers for CUDA Python projects"
+readme = {file = "README.md", content-type = "text/markdown"}
+authors = [{ name = "NVIDIA Corporation" }]
+license = "Apache-2.0"
+requires-python = ">=3.9"
+classifiers = [
+  "Programming Language :: Python :: 3 :: Only",
+  "Operating System :: POSIX :: Linux",
+]
+
+[tool.setuptools]
+packages = ["cuda_python_test_helpers"]
+
+[project.urls]
+repository = "https://github.com/NVIDIA/cuda-python"