From aa77f9941fad8fe6d7b3c39d7391a759f84aded1 Mon Sep 17 00:00:00 2001
From: Anton Volkov <antonwolfy@gmail.com>
Date: Thu, 15 Oct 2026 12:49:37 +0200
Subject: [PATCH 1/2] Deprecate unused dpnp.config settings

__DPNP_QUEUE_GPU__, __DPNP_OUTPUT_NUMPY__ and
__DPNP_OUTPUT_DPCTL_DEFAULT_SHARED__ are not used anywhere in dpnp.
Reading them now emits a DeprecationWarning; they will be removed in a
future release.
---
 dpnp/config.py            | 39 ++++++++++++++++++++++-----------------
 dpnp/tests/test_config.py | 22 ++++++++++++++++++++++
 2 files changed, 44 insertions(+), 17 deletions(-)
 create mode 100644 dpnp/tests/test_config.py

diff --git a/dpnp/config.py b/dpnp/config.py
index 0d973cdd298e..af004a990477 100644
--- a/dpnp/config.py
+++ b/dpnp/config.py
@@ -28,32 +28,37 @@
 
 
 import os
+import warnings
 
 __DPNP_ORIGIN__ = int(os.getenv("DPNP_ORIGIN", 0))
 """
 Explicitly use original host Python NumPy
 """
 
-__DPNP_QUEUE_GPU__ = int(os.getenv("DPNP_QUEUE_GPU", 0))
-"""
-Explicitly use GPU for SYCL queue
-"""
-
-__DPNP_OUTPUT_NUMPY__ = int(os.getenv("DPNP_OUTPUT_NUMPY", 0))
-"""
-Explicitly use NumPy.ndarray as return type for creation functions
-"""
-
-__DPNP_OUTPUT_DPCTL_DEFAULT_SHARED__ = int(
-    os.getenv("DPNP_OUTPUT_DPCTL_DEFAULT_SHARED", 0)
-)
-"""
-Explicitly use SYCL shared memory parameter in DPCtl array constructor for creation functions
-"""
-
 __DPNP_RAISE_EXCEPION_ON_NUMPY_FALLBACK__ = int(
     os.getenv("DPNP_RAISE_EXCEPION_ON_NUMPY_FALLBACK", 1)
 )
 """
 Trigger non-implemented exception when DPNP fallbacks on NumPy implementation
 """
+
+# settings that no longer have any effect, kept as deprecated attributes
+_DEPRECATED_SETTINGS = {
+    "__DPNP_QUEUE_GPU__": int(os.getenv("DPNP_QUEUE_GPU", 0)),
+    "__DPNP_OUTPUT_NUMPY__": int(os.getenv("DPNP_OUTPUT_NUMPY", 0)),
+    "__DPNP_OUTPUT_DPCTL_DEFAULT_SHARED__": int(
+        os.getenv("DPNP_OUTPUT_DPCTL_DEFAULT_SHARED", 0)
+    ),
+}
+
+
+def __getattr__(name):
+    if name in _DEPRECATED_SETTINGS:
+        warnings.warn(
+            f"`dpnp.config.{name}` is deprecated, and will be removed in a "
+            "future release. It has no effect.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return _DEPRECATED_SETTINGS[name]
+    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
diff --git a/dpnp/tests/test_config.py b/dpnp/tests/test_config.py
new file mode 100644
index 000000000000..b33fa39c1247
--- /dev/null
+++ b/dpnp/tests/test_config.py
@@ -0,0 +1,22 @@
+import pytest
+
+import dpnp
+
+
+class TestDeprecatedSettings:
+    @pytest.mark.parametrize(
+        "name",
+        [
+            "__DPNP_QUEUE_GPU__",
+            "__DPNP_OUTPUT_NUMPY__",
+            "__DPNP_OUTPUT_DPCTL_DEFAULT_SHARED__",
+        ],
+    )
+    def test_warns(self, name):
+        with pytest.warns(DeprecationWarning, match="has no effect"):
+            value = getattr(dpnp.config, name)
+        assert isinstance(value, int)
+
+    def test_unknown_name(self):
+        with pytest.raises(AttributeError, match="has no attribute"):
+            getattr(dpnp.config, "__DPNP_UNKNOWN__")

From 1506d2bc1e7c503f625fc7b5daa43d7a05453d66 Mon Sep 17 00:00:00 2001
From: Anton Volkov <antonwolfy@gmail.com>
Date: Thu, 15 Oct 2026 12:50:01 +0200
Subject: [PATCH 2/2] Add a changelog entry

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3d6b8161ef84..c62d963172ef 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -62,6 +62,7 @@ This release is compatible with NumPy 2.5.
 ### Deprecated
 
 * Deprecated setting the shape via the `shape` attribute of `dpnp.ndarray` and `dpnp.tensor.usm_ndarray`. Use `dpnp.reshape`/`dpnp.tensor.reshape` (or the `reshape` method) instead [#2967](https://github.com/IntelPython/dpnp/pull/2967)
+* Deprecated `dpnp.config.__DPNP_QUEUE_GPU__`, `dpnp.config.__DPNP_OUTPUT_NUMPY__` and `dpnp.config.__DPNP_OUTPUT_DPCTL_DEFAULT_SHARED__`, which have no effect; reading them now emits a `DeprecationWarning` [#3107](https://github.com/IntelPython/dpnp/pull/3107)
 
 ### Removed