From 836f2c97f99925e84ec20d3c6da335a841f63b62 Mon Sep 17 00:00:00 2001 From: Kumar Aditya Date: Wed, 18 Feb 2026 09:46:27 +0530 Subject: [PATCH] gh-144914: use `mimalloc` for raw allocations on free-threading (#144916) --- Doc/whatsnew/3.15.rst | 5 +++ Include/internal/pycore_pymem_init.h | 6 ++++ ...-02-17-18-27-28.gh-issue-144914.DcXO4m.rst | 1 + Objects/obmalloc.c | 35 ++++++++++++++++--- 4 files changed, 42 insertions(+), 5 deletions(-) create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2026-02-17-18-27-28.gh-issue-144914.DcXO4m.rst diff --git a/Doc/whatsnew/3.15.rst b/Doc/whatsnew/3.15.rst index e5714765208ff6..62ce7121424651 100644 --- a/Doc/whatsnew/3.15.rst +++ b/Doc/whatsnew/3.15.rst @@ -1204,6 +1204,11 @@ Optimizations (Contributed by Chris Eibl, Ken Jin, and Brandt Bucher in :gh:`143068`. Special thanks to the MSVC team including Hulon Jenkins.) +* ``mimalloc`` is now used as the default allocator for + for raw memory allocations such as via :c:func:`PyMem_RawMalloc` + for better performance on :term:`free-threaded builds `. + (Contributed by Kumar Aditya in :gh:`144914`.) + base64 & binascii ----------------- diff --git a/Include/internal/pycore_pymem_init.h b/Include/internal/pycore_pymem_init.h index c593edc86d9952..2a0e0817dcc7f8 100644 --- a/Include/internal/pycore_pymem_init.h +++ b/Include/internal/pycore_pymem_init.h @@ -30,6 +30,12 @@ extern void* _PyMem_MiCalloc(void *, size_t, size_t); extern void _PyMem_MiFree(void *, void *); extern void* _PyMem_MiRealloc(void *, void *, size_t); # define PYMEM_ALLOC {NULL, _PyMem_MiMalloc, _PyMem_MiCalloc, _PyMem_MiRealloc, _PyMem_MiFree} +extern void* _PyMem_MiRawMalloc(void *, size_t); +extern void* _PyMem_MiRawCalloc(void *, size_t, size_t); +extern void _PyMem_MiRawFree(void *, void *); +extern void* _PyMem_MiRawRealloc(void *, void *, size_t); +# undef PYRAW_ALLOC +# define PYRAW_ALLOC {NULL, _PyMem_MiRawMalloc, _PyMem_MiRawCalloc, _PyMem_MiRawRealloc, _PyMem_MiRawFree} #elif defined(WITH_PYMALLOC) extern void* _PyObject_Malloc(void *, size_t); extern void* _PyObject_Calloc(void *, size_t, size_t); diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-02-17-18-27-28.gh-issue-144914.DcXO4m.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-02-17-18-27-28.gh-issue-144914.DcXO4m.rst new file mode 100644 index 00000000000000..f13b8541a0ebe2 --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-02-17-18-27-28.gh-issue-144914.DcXO4m.rst @@ -0,0 +1 @@ +Use ``mimalloc`` for raw memory allocations such as via :c:func:`PyMem_RawMalloc` for better performance on :term:`free-threaded builds `. Patch by Kumar Aditya. diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c index ce2e39790bd76c..b59ebdfbda3897 100644 --- a/Objects/obmalloc.c +++ b/Objects/obmalloc.c @@ -358,6 +358,29 @@ _PyObject_MiFree(void *ctx, void *ptr) mi_free(ptr); } +void * +_PyMem_MiRawMalloc(void *ctx, size_t size) +{ + return mi_malloc(size); +} + +void * +_PyMem_MiRawCalloc(void *ctx, size_t nelem, size_t elsize) +{ + return mi_calloc(nelem, elsize); +} + +void * +_PyMem_MiRawRealloc(void *ctx, void *ptr, size_t size) +{ + return mi_realloc(ptr, size); +} + +void +_PyMem_MiRawFree(void *ctx, void *ptr) +{ + mi_free(ptr); +} #endif // WITH_MIMALLOC @@ -365,7 +388,8 @@ _PyObject_MiFree(void *ctx, void *ptr) #ifdef WITH_MIMALLOC -# define MIMALLOC_ALLOC {NULL, _PyMem_MiMalloc, _PyMem_MiCalloc, _PyMem_MiRealloc, _PyMem_MiFree} +# define MIMALLOC_ALLOC {NULL, _PyMem_MiMalloc, _PyMem_MiCalloc, _PyMem_MiRealloc, _PyMem_MiFree} +# define MIMALLOC_RAWALLOC {NULL, _PyMem_MiRawMalloc, _PyMem_MiRawCalloc, _PyMem_MiRawRealloc, _PyMem_MiRawFree} # define MIMALLOC_OBJALLOC {NULL, _PyObject_MiMalloc, _PyObject_MiCalloc, _PyObject_MiRealloc, _PyObject_MiFree} #endif @@ -383,7 +407,7 @@ void* _PyObject_Realloc(void *ctx, void *ptr, size_t size); #if defined(Py_GIL_DISABLED) // Py_GIL_DISABLED requires using mimalloc for "mem" and "obj" domains. -# define PYRAW_ALLOC MALLOC_ALLOC +# define PYRAW_ALLOC MIMALLOC_RAWALLOC # define PYMEM_ALLOC MIMALLOC_ALLOC # define PYOBJ_ALLOC MIMALLOC_OBJALLOC #elif defined(WITH_PYMALLOC) @@ -758,7 +782,7 @@ set_up_allocators_unlocked(PyMemAllocatorName allocator) case PYMEM_ALLOCATOR_MIMALLOC: case PYMEM_ALLOCATOR_MIMALLOC_DEBUG: { - PyMemAllocatorEx malloc_alloc = MALLOC_ALLOC; + PyMemAllocatorEx malloc_alloc = MIMALLOC_RAWALLOC; set_allocator_unlocked(PYMEM_DOMAIN_RAW, &malloc_alloc); PyMemAllocatorEx pymalloc = MIMALLOC_ALLOC; @@ -828,6 +852,7 @@ get_current_allocator_name_unlocked(void) #ifdef WITH_MIMALLOC PyMemAllocatorEx mimalloc = MIMALLOC_ALLOC; PyMemAllocatorEx mimalloc_obj = MIMALLOC_OBJALLOC; + PyMemAllocatorEx mimalloc_raw = MIMALLOC_RAWALLOC; #endif if (pymemallocator_eq(&_PyMem_Raw, &malloc_alloc) && @@ -845,7 +870,7 @@ get_current_allocator_name_unlocked(void) } #endif #ifdef WITH_MIMALLOC - if (pymemallocator_eq(&_PyMem_Raw, &malloc_alloc) && + if (pymemallocator_eq(&_PyMem_Raw, &mimalloc_raw) && pymemallocator_eq(&_PyMem, &mimalloc) && pymemallocator_eq(&_PyObject, &mimalloc_obj)) { @@ -877,7 +902,7 @@ get_current_allocator_name_unlocked(void) } #endif #ifdef WITH_MIMALLOC - if (pymemallocator_eq(&_PyMem_Debug.raw.alloc, &malloc_alloc) && + if (pymemallocator_eq(&_PyMem_Debug.raw.alloc, &mimalloc_raw) && pymemallocator_eq(&_PyMem_Debug.mem.alloc, &mimalloc) && pymemallocator_eq(&_PyMem_Debug.obj.alloc, &mimalloc_obj)) {