mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-11-01 18:51:43 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 21

gh-112532: Isolate abandoned segments by interpreter (#113717)

Browse source 
* gh-112532: Isolate abandoned segments by interpreter

Mimalloc segments are data structures that contain memory allocations along
with metadata. Each segment is "owned" by a thread. When a thread exits,
it abandons its segments to a global pool to be later reclaimed by other
threads. This changes the pool to be per-interpreter instead of process-wide.

This will be important for when we use mimalloc to find GC objects in the
`--disable-gil` builds. We want heaps to only store Python objects from a
single interpreter. Absent this change, the abandoning and reclaiming process
could break this isolation.

* Add missing '&_mi_abandoned_default' to 'tld_empty'
This commit is contained in:
Sam Gross 2024-01-04 17:21:40 -05:00 • committed by GitHub
parent c2e8298eba
commit fcb3c2a444
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
7 changed files with 102 additions and 76 deletions
Download patch file Download diff file Expand all files Collapse all files

20
Include/internal/mimalloc/mimalloc/internal.h
View file

@ -23,23 +23,6 @@ terms of the MIT license. A copy of the license can be found in the file
#define mi_trace_message(...)
#endif
#define MI_CACHE_LINE 64
#if defined(_MSC_VER)
#pragma warning(disable:4127) // suppress constant conditional warning (due to MI_SECURE paths)
#pragma warning(disable:26812) // unscoped enum warning
#define mi_decl_noinline __declspec(noinline)
#define mi_decl_thread __declspec(thread)
#define mi_decl_cache_align __declspec(align(MI_CACHE_LINE))
#elif (defined(__GNUC__) && (__GNUC__ >= 3)) || defined(__clang__) // includes clang and icc
#define mi_decl_noinline __attribute__((noinline))
#define mi_decl_thread __thread
#define mi_decl_cache_align __attribute__((aligned(MI_CACHE_LINE)))
#else
#define mi_decl_noinline
#define mi_decl_thread __thread // hope for the best :-)
#define mi_decl_cache_align
#endif
#if defined(__EMSCRIPTEN__) && !defined(__wasi__)
#define __wasi__
#endif
@ -131,6 +114,7 @@ void _mi_segment_map_allocated_at(const mi_segment_t* segment);
void _mi_segment_map_freed_at(const mi_segment_t* segment);
// "segment.c"
extern mi_abandoned_pool_t _mi_abandoned_default; // global abandoned pool
mi_page_t* _mi_segment_page_alloc(mi_heap_t* heap, size_t block_size, size_t page_alignment, mi_segments_tld_t* tld, mi_os_tld_t* os_tld);
void _mi_segment_page_free(mi_page_t* page, bool force, mi_segments_tld_t* tld);
void _mi_segment_page_abandon(mi_page_t* page, mi_segments_tld_t* tld);
@ -145,7 +129,7 @@ void _mi_segment_huge_page_reset(mi_segment_t* segment, mi_page_t* page, m
uint8_t* _mi_segment_page_start(const mi_segment_t* segment, const mi_page_t* page, size_t* page_size); // page start for any page
void _mi_abandoned_reclaim_all(mi_heap_t* heap, mi_segments_tld_t* tld);
void _mi_abandoned_await_readers(void);
void _mi_abandoned_await_readers(mi_abandoned_pool_t *pool);
void _mi_abandoned_collect(mi_heap_t* heap, bool force, mi_segments_tld_t* tld);
// "page.c"

40
Include/internal/mimalloc/mimalloc/types.h
View file

@ -33,6 +33,23 @@ terms of the MIT license. A copy of the license can be found in the file
#define MI_MAX_ALIGN_SIZE 16 // sizeof(max_align_t)
#endif
#define MI_CACHE_LINE 64
#if defined(_MSC_VER)
#pragma warning(disable:4127) // suppress constant conditional warning (due to MI_SECURE paths)
#pragma warning(disable:26812) // unscoped enum warning
#define mi_decl_noinline __declspec(noinline)
#define mi_decl_thread __declspec(thread)
#define mi_decl_cache_align __declspec(align(MI_CACHE_LINE))
#elif (defined(__GNUC__) && (__GNUC__ >= 3)) || defined(__clang__) // includes clang and icc
#define mi_decl_noinline __attribute__((noinline))
#define mi_decl_thread __thread
#define mi_decl_cache_align __attribute__((aligned(MI_CACHE_LINE)))
#else
#define mi_decl_noinline
#define mi_decl_thread __thread // hope for the best :-)
#define mi_decl_cache_align
#endif
// ------------------------------------------------------
// Variants
// ------------------------------------------------------
@ -445,6 +462,28 @@ typedef struct mi_segment_s {
mi_slice_t slices[MI_SLICES_PER_SEGMENT+1]; // one more for huge blocks with large alignment
} mi_segment_t;
typedef uintptr_t mi_tagged_segment_t;
// Segments unowned by any thread are put in a shared pool
typedef struct mi_abandoned_pool_s {
// This is a list of visited abandoned pages that were full at the time.
// this list migrates to `abandoned` when that becomes NULL. The use of
// this list reduces contention and the rate at which segments are visited.
mi_decl_cache_align _Atomic(mi_segment_t*) abandoned_visited; // = NULL
// The abandoned page list (tagged as it supports pop)
mi_decl_cache_align _Atomic(mi_tagged_segment_t) abandoned; // = NULL
// Maintain these for debug purposes (these counts may be a bit off)
mi_decl_cache_align _Atomic(size_t) abandoned_count;
mi_decl_cache_align _Atomic(size_t) abandoned_visited_count;
// We also maintain a count of current readers of the abandoned list
// in order to prevent resetting/decommitting segment memory if it might
// still be read.
mi_decl_cache_align _Atomic(size_t) abandoned_readers; // = 0
} mi_abandoned_pool_t;
// ------------------------------------------------------
// Heaps
@ -654,6 +693,7 @@ typedef struct mi_segments_tld_s {
size_t peak_size; // peak size of all segments
mi_stats_t* stats; // points to tld stats
mi_os_tld_t* os; // points to os stats
mi_abandoned_pool_t* abandoned; // pool of abandoned segments
} mi_segments_tld_t;
// Thread local data