Merge pull request #21498 from jakirkham/add_get_madv_hp

ENH: Add `_get_madvise_hugepage` function

5 files changed, 34 insertions, 1 deletions

diff --git a/numpy/core/_add_newdocs.py b/numpy/core/_add_newdocs.py
index baafc9127..304c3a61b 100644
--- a/numpy/core/_add_newdocs.py
+++ b/numpy/core/_add_newdocs.py
@@ -4865,6 +4865,15 @@ add_newdoc('numpy.core.multiarray', 'get_handler_version',
     its memory, in which case you can traverse ``a.base`` for a memory handler.
     """)
 
+add_newdoc('numpy.core.multiarray', '_get_madvise_hugepage',
+    """
+    _get_madvise_hugepage() -> bool
+
+    Get use of ``madvise (2)`` MADV_HUGEPAGE support when
+    allocating the array data. Returns the currently set value.
+    See `global_state` for more information.
+    """)
+
 add_newdoc('numpy.core.multiarray', '_set_madvise_hugepage',
     """
     _set_madvise_hugepage(enabled: bool) -> bool
diff --git a/numpy/core/multiarray.py b/numpy/core/multiarray.py
index 1a37ed3e1..ee88ce30b 100644
--- a/numpy/core/multiarray.py
+++ b/numpy/core/multiarray.py
@@ -16,7 +16,7 @@ from ._multiarray_umath import *  # noqa: F403
 from ._multiarray_umath import (
     _fastCopyAndTranspose, _flagdict, from_dlpack, _insert, _reconstruct,
     _vec_string, _ARRAY_API, _monotonicity, _get_ndarray_c_version,
-    _set_madvise_hugepage,
+    _get_madvise_hugepage, _set_madvise_hugepage,
     )
 
 __all__ = [
diff --git a/numpy/core/src/multiarray/alloc.c b/numpy/core/src/multiarray/alloc.c
index 759a02aeb..6f18054ff 100644
--- a/numpy/core/src/multiarray/alloc.c
+++ b/numpy/core/src/multiarray/alloc.c
@@ -39,6 +39,25 @@ static int _madvise_hugepage = 1;
 
 
 /*
+ * This function tells whether NumPy attempts to call `madvise` with
+ * `MADV_HUGEPAGE`.  `madvise` is only ever used on linux, so the value
+ * of `_madvise_hugepage` may be ignored.
+ *
+ * It is exposed to Python as `np.core.multiarray._get_madvise_hugepage`.
+ */
+NPY_NO_EXPORT PyObject *
+_get_madvise_hugepage(PyObject *NPY_UNUSED(self), PyObject *NPY_UNUSED(args))
+{
+#ifdef NPY_OS_LINUX
+    if (_madvise_hugepage) {
+        Py_RETURN_TRUE;
+    }
+#endif
+    Py_RETURN_FALSE;
+}
+
+
+/*
  * This function enables or disables the use of `MADV_HUGEPAGE` on Linux
  * by modifying the global static `_madvise_hugepage`.
  * It returns the previous value of `_madvise_hugepage`.
diff --git a/numpy/core/src/multiarray/alloc.h b/numpy/core/src/multiarray/alloc.h
index 13c828458..e82f2d947 100644
--- a/numpy/core/src/multiarray/alloc.h
+++ b/numpy/core/src/multiarray/alloc.h
@@ -8,6 +8,9 @@
 #define NPY_TRACE_DOMAIN 389047
 
 NPY_NO_EXPORT PyObject *
+_get_madvise_hugepage(PyObject *NPY_UNUSED(self), PyObject *NPY_UNUSED(args));
+
+NPY_NO_EXPORT PyObject *
 _set_madvise_hugepage(PyObject *NPY_UNUSED(self), PyObject *enabled_obj);
 
 NPY_NO_EXPORT void *
diff --git a/numpy/core/src/multiarray/multiarraymodule.c b/numpy/core/src/multiarray/multiarraymodule.c
index 5e51bcaa6..ce47276db 100644
--- a/numpy/core/src/multiarray/multiarraymodule.c
+++ b/numpy/core/src/multiarray/multiarraymodule.c
@@ -4488,6 +4488,8 @@ static struct PyMethodDef array_module_methods[] = {
         METH_VARARGS, NULL},
     {"_get_sfloat_dtype",
         get_sfloat_dtype, METH_NOARGS, NULL},
+    {"_get_madvise_hugepage", (PyCFunction)_get_madvise_hugepage,
+        METH_NOARGS, NULL},
     {"_set_madvise_hugepage", (PyCFunction)_set_madvise_hugepage,
         METH_O, NULL},
     {"_reload_guard", (PyCFunction)_reload_guard,