* Update vendored mimalloc to v2.5.2
Upgrade mimalloc from v2.1.2 to v2.5.2 as-is from upstream.
v2.1.2: https://github.com/microsoft/mimalloc/releases/tag/v2.1.2
v2.5.2: https://github.com/microsoft/mimalloc/releases/tag/v2.5.2
* Re-apply CPython-specific changes to mimalloc v2.5.2
Most of the previous downstream changes were upstreamed in mimalloc
v2.1.3 - v2.1.7 (heap tags, _mi_heap_init/_mi_tld_init, MI_PRIM_THREAD_ID,
sub-processes, heap walk optimizations, platform fixes) and are dropped.
Remaining CPython-specific changes, all marked with a "CPython" comment:
- QSBR delayed page freeing for free-threaded builds (gh-115103,
gh-145615): mi_page_t/mi_heap_t fields and _PyMem_mi_* hooks in
page.c, heap.c and segment.c.
- debug_offset: preserve the first bytes of a PyObject (ob_tid, refcount
fields) when filling freed or uninitialized memory in debug builds
(gh-115491).
- Atomic mi_block_t.next loads/stores to avoid TSAN reports (gh-129748).
- Relax the owning thread assertion in _mi_free_delayed_block for
free-threaded builds, since the GC traverses heaps of other threads.
- Call _mi_heap_delayed_free_partial() in mi_heap_visit_blocks()
(gh-112532).
- Only count reclaimed pages up to MI_MEDIUM_OBJ_SIZE_MAX as a
"right page" in mi_segment_reclaim (gh-115103).
- Rename the weak _ZSt15get_new_handlerv symbol and disable the
mi_is_in_heap_region debug warning.
- Zero-initialize _mi_page_empty instead of a positional initializer.
* Update the free-threaded build to mimalloc v2.5.2 changes
mimalloc v2.1.4 replaced the list of abandoned segments with per-arena
bitmaps and introduced sub-processes (mi_subproc_t) to keep abandoned
segments of separate interpreters apart. Use them instead of the
CPython-specific mi_abandoned_pool_t:
- Each interpreter owns a mi_subproc_t created in init_interpreter().
- tstate_mimalloc_bind() sets tld->segments.subproc and uses the
upstream _mi_heap_init() signature.
- The GC and sys.getallocatedblocks() visit abandoned segments with
_PyMem_mi_visit_abandoned_blocks(), the upstream cursor API without
the mi_option_visit_abandoned requirement, while STW.
* Update NEWS.d
* fix MSAN
* fix TSAN
* fix test_cext
* Disable THP
* Address code review
* Address code review
* Address code review
* nit
* Address code review
* Address code review
Donghee Na
aff7a2e23b