Merge branch 'main' into base64-decode-ignore-pad-char

Author: serhiy-storchaka

Android/testbed/app/build.gradle.kts

@@ -92,7 +92,12 @@ android {
             }
             throw GradleException("Failed to find API level in $androidEnvFile")
         }
-        targetSdk = 35
+
+        // This controls the API level of the maxVersion managed emulator, which is used
+        // by CI and cibuildwheel. 34 takes up too much disk space (#142289), 35 has
+        // issues connecting to the internet (#142387), and 36 and later are not
+        // available as aosp_atd images yet.
+        targetSdk = 33
 
         versionCode = 1
         versionName = "1.0"

Doc/c-api/memory.rst

@@ -677,7 +677,11 @@ The pymalloc allocator
 Python has a *pymalloc* allocator optimized for small objects (smaller or equal
 to 512 bytes) with a short lifetime. It uses memory mappings called "arenas"
 with a fixed size of either 256 KiB on 32-bit platforms or 1 MiB on 64-bit
-platforms. It falls back to :c:func:`PyMem_RawMalloc` and
+platforms. When Python is configured with :option:`--with-pymalloc-hugepages`,
+the arena size on 64-bit platforms is increased to 2 MiB to match the huge page
+size, and arena allocation will attempt to use huge pages (``MAP_HUGETLB`` on
+Linux, ``MEM_LARGE_PAGES`` on Windows) with automatic fallback to regular pages.
+It falls back to :c:func:`PyMem_RawMalloc` and
 :c:func:`PyMem_RawRealloc` for allocations larger than 512 bytes.
 
 *pymalloc* is the :ref:`default allocator <default-memory-allocators>` of the

Doc/using/configure.rst

@@ -783,6 +783,21 @@ also be used to improve performance.
 
    See also :envvar:`PYTHONMALLOC` environment variable.
 
+.. option:: --with-pymalloc-hugepages
+
+   Enable huge page support for :ref:`pymalloc <pymalloc>` arenas (disabled by
+   default). When enabled, the arena size on 64-bit platforms is increased to
+   2 MiB and arena allocation uses ``MAP_HUGETLB`` (Linux) or
+   ``MEM_LARGE_PAGES`` (Windows) with automatic fallback to regular pages.
+
+   The configure script checks that the platform supports ``MAP_HUGETLB``
+   and emits a warning if it is not available.
+
+   On Windows, use the ``--pymalloc-hugepages`` flag with ``build.bat`` or
+   set the ``UsePymallocHugepages`` MSBuild property.
+
+   .. versionadded:: 3.15
+
 .. option:: --without-doc-strings
 
    Disable static documentation strings to reduce the memory footprint (enabled

Doc/whatsnew/3.15.rst

@@ -1477,6 +1477,12 @@ Build changes
   modules that are missing or packaged separately.
   (Contributed by Stan Ulbrych and Petr Viktorin in :gh:`139707`.)
 
+* The new configure option :option:`--with-pymalloc-hugepages` enables huge
+  page support for :ref:`pymalloc <pymalloc>` arenas. When enabled, arena size
+  increases to 2 MiB and allocation uses ``MAP_HUGETLB`` (Linux) or
+  ``MEM_LARGE_PAGES`` (Windows) with automatic fallback to regular pages.
+  On Windows, use ``build.bat --pymalloc-hugepages``.
+
 * Annotating anonymous mmap usage is now supported if Linux kernel supports
   :manpage:`PR_SET_VMA_ANON_NAME <PR_SET_VMA(2const)>` (Linux 5.17 or newer).
   Annotations are visible in ``/proc/<pid>/maps`` if the kernel supports the feature

Include/internal/pycore_obmalloc.h

@@ -208,7 +208,11 @@ typedef unsigned int pymem_uint;  /* assuming >= 16 bits */
  * mappings to reduce heap fragmentation.
  */
 #ifdef USE_LARGE_ARENAS
-#define ARENA_BITS              20                    /* 1 MiB */
+#  ifdef PYMALLOC_USE_HUGEPAGES
+#    define ARENA_BITS            21                    /* 2 MiB */
+#  else
+#    define ARENA_BITS            20                    /* 1 MiB */
+#  endif
 #else
 #define ARENA_BITS              18                    /* 256 KiB */
 #endif
@@ -469,7 +473,7 @@ nfp free pools in usable_arenas.
 */
 
 /* How many arena_objects do we initially allocate?
- * 16 = can allocate 16 arenas = 16 * ARENA_SIZE = 4MB before growing the
+ * 16 = can allocate 16 arenas = 16 * ARENA_SIZE before growing the
  * `arenas` vector.
  */
 #define INITIAL_ARENA_OBJECTS 16
@@ -512,14 +516,26 @@ struct _obmalloc_mgmt {
 
    memory address bit allocation for keys
 
-   64-bit pointers, IGNORE_BITS=0 and 2^20 arena size:
+   ARENA_BITS is configurable: 20 (1 MiB) by default on 64-bit, or
+   21 (2 MiB) when PYMALLOC_USE_HUGEPAGES is enabled.  All bit widths
+   below are derived from ARENA_BITS automatically.
+
+   64-bit pointers, IGNORE_BITS=0 and 2^20 arena size (default):
      15 -> MAP_TOP_BITS
      15 -> MAP_MID_BITS
      14 -> MAP_BOT_BITS
      20 -> ideal aligned arena
    ----
      64
 
+   64-bit pointers, IGNORE_BITS=0 and 2^21 arena size (hugepages):
+     15 -> MAP_TOP_BITS
+     15 -> MAP_MID_BITS
+     13 -> MAP_BOT_BITS
+     21 -> ideal aligned arena
+   ----
+     64
+
    64-bit pointers, IGNORE_BITS=16, and 2^20 arena size:
      16 -> IGNORE_BITS
      10 -> MAP_TOP_BITS

Lib/test/test_binascii.py

@@ -214,6 +214,17 @@ def assertNonBase64Data(data, expected, ignorechars):
         assertNonBase64Data(b'a\nb==', b'i', ignorechars=bytearray(b'\n'))
         assertNonBase64Data(b'a\nb==', b'i', ignorechars=memoryview(b'\n'))
 
+        # Same cell in the cache: '\r' >> 3 == '\n' >> 3.
+        data = self.type2test(b'\r\n')
+        with self.assertRaises(binascii.Error):
+            binascii.a2b_base64(data, ignorechars=b'\r')
+        self.assertEqual(binascii.a2b_base64(data, ignorechars=b'\r\n'), b'')
+        # Same bit mask in the cache: '*' & 31 == '\n' & 31.
+        data = self.type2test(b'*\n')
+        with self.assertRaises(binascii.Error):
+            binascii.a2b_base64(data, ignorechars=b'*')
+        self.assertEqual(binascii.a2b_base64(data, ignorechars=b'*\n'), b'')
+
         data = self.type2test(b'a\nb==')
         with self.assertRaises(TypeError):
             binascii.a2b_base64(data, ignorechars='')

Misc/NEWS.d/next/Build/2026-01-28-19-04-12.gh-issue-144309.3sMFOh.rst

@@ -0,0 +1 @@
+Build Python with POSIX 2024, instead of POSIX 2008. Patch by Victor Stinner.

Misc/NEWS.d/next/Core_and_Builtins/2026-01-29-01-42-14.gh-issue-144319._7EtdB.rst

@@ -0,0 +1 @@
+Add huge pages support for the pymalloc allocator. Patch by Pablo Galindo

Misc/NEWS.d/next/Library/2026-01-27-10-02-04.gh-issue-144264.Wmzbol.rst

@@ -0,0 +1,3 @@
+Speed up Base64 decoding of data containing ignored characters (both in
+non-strict mode and with an explicit *ignorechars* argument).
+It is now up to 2 times faster for multiline Base64 data.

Misc/NEWS.d/next/Library/2026-01-27-14-23-10.gh-issue-144206.l0un4U.rst

@@ -0,0 +1,2 @@
+Improve error messages for buffer overflow in :func:`fcntl.fcntl` and
+:func:`fcntl.ioctl`.