Revert nvJitLink driver-major compatibility fallback (NVIDIA#2355)

isVoid · web-flow · commit 60d431f78daf · 2026-07-17T11:04:02.000-07:00
* Revert "Check nvJitLink driver major compatibility (NVIDIA#2320)" This reverts commit e83d434. * Fix cuLink state storage lifetimes * Preserve linker backend validation test fix * Skip unsupported cuLink time option tests --------- Co-authored-by: Michael Wang <isVoid@users.noreply.github.com>
diff --git a/cuda_core/cuda/core/_linker.pyi b/cuda_core/cuda/core/_linker.pyi
@@ -112,8 +112,7 @@ class LinkerOptions:
 
     Since the linker may choose to use nvJitLink or the driver APIs as the linking backend,
     not all options are applicable. When the system's installed nvJitLink is too old (<12.3),
-    not installed, or older than the CUDA driver major version, the driver APIs (cuLink)
-    will be used instead.
+    or not installed, the driver APIs (cuLink) will be used instead.
 
     Attributes
     ----------
diff --git a/cuda_core/cuda/core/_linker.pyx b/cuda_core/cuda/core/_linker.pyx
@@ -39,7 +39,6 @@ from cuda.core._utils.cuda_utils import (
     driver,
     is_sequence,
 )
-from cuda.core._utils.version import driver_version
 from cuda.core.typing import CompilerBackendType, ObjectCodeFormatType
 
 if TYPE_CHECKING:
@@ -218,8 +217,7 @@ class LinkerOptions:
 
     Since the linker may choose to use nvJitLink or the driver APIs as the linking backend,
     not all options are applicable. When the system's installed nvJitLink is too old (<12.3),
-    not installed, or older than the CUDA driver major version, the driver APIs (cuLink)
-    will be used instead.
+    or not installed, the driver APIs (cuLink) will be used instead.
 
     Attributes
     ----------
@@ -696,22 +694,12 @@ def _decide_nvjitlink_or_driver() -> bool:
         from cuda.bindings._internal import nvjitlink
 
         if _nvjitlink_has_version_symbol(nvjitlink):
-            nvjitlink_version = nvjitlink_module.version()
-            driver_major = driver_version()[0]
-            if driver_major <= nvjitlink_version[0]:
-                _use_nvjitlink_backend = True
-                return False  # Use nvjitlink
-
-            warn_txt = (
-                f"CUDA driver major version {driver_major} is newer than "
-                f"nvJitLink major version {nvjitlink_version[0]}; therefore "
-                f"{warn_txt_common} nvJitLink."
-            )
-        else:
-            warn_txt = (
-                f"{'nvJitLink*.dll' if sys.platform == 'win32' else 'libnvJitLink.so*'} is too old (<12.3)."
-                f" Therefore cuda.bindings.nvjitlink is not usable and {warn_txt_common} nvJitLink."
-            )
+            _use_nvjitlink_backend = True
+            return False  # Use nvjitlink
+        warn_txt = (
+            f"{'nvJitLink*.dll' if sys.platform == 'win32' else 'libnvJitLink.so*'} is too old (<12.3)."
+            f" Therefore cuda.bindings.nvjitlink is not usable and {warn_txt_common} nvJitLink."
+        )
 
     warn(warn_txt, stacklevel=2, category=RuntimeWarning)
     _use_nvjitlink_backend = False
diff --git a/cuda_core/tests/test_optional_dependency_imports.py b/cuda_core/tests/test_optional_dependency_imports.py
@@ -7,14 +7,6 @@
 from cuda.core import _linker, _program
 
 
-class FakeNvJitLinkModule:
-    def __init__(self, version):
-        self._version = version
-
-    def version(self):
-        return self._version
-
-
 @pytest.fixture(autouse=True)
 def restore_optional_import_state():
     saved_nvvm_module = _program._nvvm_module
@@ -111,43 +103,3 @@ def fake__optional_cuda_import(modname, probe_function=None):
 
     assert use_driver_backend is True
     assert _linker._use_nvjitlink_backend is False
-
-
-@pytest.mark.agent_authored(model="gpt-5")
-@pytest.mark.parametrize(
-    ("driver_version", "nvjitlink_version"),
-    [
-        ((12, 8, 0), (12, 9)),
-        ((12, 9, 0), (13, 0)),
-    ],
-)
-def test_decide_nvjitlink_or_driver_uses_nvjitlink_when_driver_is_not_newer(
-    monkeypatch, driver_version, nvjitlink_version
-):
-    monkeypatch.setattr(
-        _linker,
-        "_optional_cuda_import",
-        lambda *_args, **_kwargs: FakeNvJitLinkModule(nvjitlink_version),
-    )
-    monkeypatch.setattr(_linker, "_nvjitlink_has_version_symbol", lambda _nvjitlink: True)
-    monkeypatch.setattr(_linker, "driver_version", lambda: driver_version)
-
-    assert _linker._decide_nvjitlink_or_driver() is False
-    assert _linker._use_nvjitlink_backend is True
-
-
-@pytest.mark.agent_authored(model="gpt-5")
-def test_decide_nvjitlink_or_driver_falls_back_when_driver_is_newer(monkeypatch):
-    monkeypatch.setattr(
-        _linker,
-        "_optional_cuda_import",
-        lambda *_args, **_kwargs: FakeNvJitLinkModule((12, 9)),
-    )
-    monkeypatch.setattr(_linker, "_nvjitlink_has_version_symbol", lambda _nvjitlink: True)
-    monkeypatch.setattr(_linker, "driver_version", lambda: (13, 0, 0))
-
-    with pytest.warns(RuntimeWarning, match="is newer than nvJitLink major version"):
-        use_driver_backend = _linker._decide_nvjitlink_or_driver()
-
-    assert use_driver_backend is True
-    assert _linker._use_nvjitlink_backend is False
diff --git a/cuda_core/tests/test_program_cache.py b/cuda_core/tests/test_program_cache.py
@@ -375,6 +375,14 @@ def test_make_program_cache_key_ignores_name_expressions_for_non_nvrtc(code_type
             {"link_time_optimization": None},
             id="lto_false_eq_none",
         ),
+        # ``time`` is a presence gate: the linker emits ``-time`` for any
+        # non-None value, so True / "path" produce the same flag.
+        pytest.param(
+            {"time": True},
+            {"time": "timing.csv"},
+            id="time_true_eq_path",
+            marks=pytest.mark.skipif(is_culink_backend, reason="-time is not supported in cuLink"),
+        ),
         # ``no_cache`` has an ``is True`` gate; False and None equivalent.
         pytest.param({"no_cache": False}, {"no_cache": None}, id="no_cache_false_eq_none"),
     ],
@@ -393,18 +401,6 @@ def test_make_program_cache_key_ptx_linker_equivalent_options_hash_same(a, b, mo
     assert k_a == k_b
 
 
-@pytest.mark.skipif(is_culink_backend, reason="test requires nvJitLink backend")
-@pytest.mark.agent_authored(model="gpt-5")
-def test_make_program_cache_key_ptx_nvjitlink_time_values_hash_same(monkeypatch):
-    """nvJitLink emits ``-time`` for any non-None value."""
-    from cuda.core.utils import _program_cache
-
-    monkeypatch.setattr(_program_cache._keys, "_linker_backend_and_version", lambda _use_driver: ("nvJitLink", "12030"))
-    k_true = _make_key(code=".version 7.0", code_type="ptx", options=_opts(time=True))
-    k_path = _make_key(code=".version 7.0", code_type="ptx", options=_opts(time="timing.csv"))
-    assert k_true == k_path
-
-
 @pytest.mark.parametrize(
     "field, a, b",
     [
@@ -1014,9 +1010,10 @@ def test_make_program_cache_key_rejects_side_effect_options_nvrtc(option_kw, ext
         pytest.param({"time": "whatever.csv"}, id="time_path"),
     ],
 )
-@pytest.mark.skipif(is_culink_backend, reason="test requires nvJitLink backend")
+@pytest.mark.skipif(is_culink_backend, reason="-time is not supported in cuLink")
 def test_make_program_cache_key_accepts_side_effect_options_for_ptx(option_kw):
-    """nvJitLink ``-time`` writes only to its info log, not the filesystem."""
+    """The side-effect guard is NVRTC-specific: PTX (linker) and NVVM must
+    not be blocked by options whose side effects only apply under NVRTC."""
     _make_key(code=".version 7.0", code_type="ptx", options=_opts(**option_kw))  # no raise
 
 
