Add requirements.txt, missing patch to ASV benchmarks

benchmarks/asv.conf.json

@@ -19,6 +19,6 @@
     "build_cache_size": 2,
     "default_benchmark_timeout": 500,
     "regressions_thresholds": {
-        ".*": 0.3
+        ".*": 0.2
     }
 }

benchmarks/benchmarks/__init__.py

@@ -4,6 +4,8 @@
 
 import psutil
 
+from ._patch_setup import _apply_patches
+
 _MIN_THREADS = 4  # minimum physical cores required for multi-threaded mode
 
 
@@ -19,3 +21,6 @@ def _thread_count():
 
 _THREADS = os.environ.get("MKL_NUM_THREADS", _thread_count())
 os.environ["MKL_NUM_THREADS"] = _THREADS
+
+_apply_patches()
+del _apply_patches

benchmarks/benchmarks/_patch_setup.py

@@ -0,0 +1,67 @@
+"""MKL patch setup — executed once per ASV worker process at import time.
+
+Patches NumPy FFT with the Intel MKL FFT implementation.
+Hard-fails with a descriptive RuntimeError if mkl_fft is missing or the
+patch does not take effect, so benchmarks never silently run on stock NumPy.
+"""
+
+_PATCH_MAP = [
+    ("mkl_fft", "patch_numpy_fft"),
+]
+
+
+def _apply_patches():
+    import importlib
+
+    import numpy as np
+
+    patched = {}
+
+    for mod_name, patch_fn_name in _PATCH_MAP:
+        try:
+            mod = importlib.import_module(mod_name)
+        except ImportError as exc:
+            raise RuntimeError(
+                f"[mkl-patch] Cannot import {mod_name}: {exc}\n"
+                f"  Ensure the conda env contains {mod_name} "
+                f"from the Intel channel.\n"
+                "  Required channels: "
+                "https://software.repos.intel.com/python/conda"
+            ) from exc
+
+        patch_fn = getattr(mod, patch_fn_name, None)
+        if patch_fn is None:
+            raise RuntimeError(
+                f"[mkl-patch] {mod_name} has no {patch_fn_name}(). "
+                f"Upgrade {mod_name} to a version that exposes "
+                "the stock-numpy patch API."
+            )
+
+        try:
+            patch_fn()
+        except Exception as exc:
+            raise RuntimeError(
+                f"[mkl-patch] {mod_name}.{patch_fn_name}() raised: {exc!r}"
+            ) from exc
+
+        is_patched_fn = getattr(mod, "is_patched", None)
+        if callable(is_patched_fn) and not is_patched_fn():
+            raise RuntimeError(
+                f"[mkl-patch] {mod_name}.is_patched() returned False "
+                "after patching. NumPy may have been imported before "
+                "patching in a conflicting state."
+            )
+
+        patched[mod_name] = mod
+
+    _attr_checks = {
+        "mkl_fft": lambda: np.fft.fft.__module__,
+    }
+    for mod_name in patched:
+        try:
+            attr = _attr_checks[mod_name]()
+        except Exception:
+            attr = "unknown"
+        print(f"[mkl-patch] {mod_name}: numpy.fft dispatch -> {attr}")
+
+    print("[mkl-patch] ALL OK -- mkl_fft active")

benchmarks/requirements.txt

@@ -0,0 +1,2 @@
+psutil
+scipy