BUG: ArrayManager construction unwanted copy (#42689)

Author: jbrockmendel

pandas/core/internals/construction.py

@@ -331,14 +331,14 @@ def ndarray_to_mgr(
         if dtype is None and is_object_dtype(values.dtype):
             arrays = [
                 ensure_wrapped_if_datetimelike(
-                    maybe_infer_to_datetimelike(values[:, i].copy())
+                    maybe_infer_to_datetimelike(values[:, i])
                 )
                 for i in range(values.shape[1])
             ]
         else:
             if is_datetime_or_timedelta_dtype(values.dtype):
                 values = ensure_wrapped_if_datetimelike(values)
-            arrays = [values[:, i].copy() for i in range(values.shape[1])]
+            arrays = [values[:, i] for i in range(values.shape[1])]
 
         return ArrayManager(arrays, [index, columns], verify_integrity=False)
 

pandas/tests/frame/methods/test_values.py

@@ -226,10 +226,7 @@ def test_values_lcd(self, mixed_float_frame, mixed_int_frame):
 
 
 class TestPrivateValues:
-    def test_private_values_dt64tz(self, using_array_manager, request):
-        if using_array_manager:
-            mark = pytest.mark.xfail(reason="doesn't share memory")
-            request.node.add_marker(mark)
+    def test_private_values_dt64tz(self, request):
 
         dta = date_range("2000", periods=4, tz="US/Central")._data.reshape(-1, 1)