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Diffstat (limited to 'src/mimalloc/arena.c')
| -rw-r--r-- | src/mimalloc/arena.c | 936 |
1 files changed, 936 insertions, 0 deletions
diff --git a/src/mimalloc/arena.c b/src/mimalloc/arena.c new file mode 100644 index 000000000..a04a04c8f --- /dev/null +++ b/src/mimalloc/arena.c @@ -0,0 +1,936 @@ +/* ---------------------------------------------------------------------------- +Copyright (c) 2019-2023, Microsoft Research, Daan Leijen +This is free software; you can redistribute it and/or modify it under the +terms of the MIT license. A copy of the license can be found in the file +"LICENSE" at the root of this distribution. +-----------------------------------------------------------------------------*/ + +/* ---------------------------------------------------------------------------- +"Arenas" are fixed area's of OS memory from which we can allocate +large blocks (>= MI_ARENA_MIN_BLOCK_SIZE, 4MiB). +In contrast to the rest of mimalloc, the arenas are shared between +threads and need to be accessed using atomic operations. + +Arenas are used to for huge OS page (1GiB) reservations or for reserving +OS memory upfront which can be improve performance or is sometimes needed +on embedded devices. We can also employ this with WASI or `sbrk` systems +to reserve large arenas upfront and be able to reuse the memory more effectively. + +The arena allocation needs to be thread safe and we use an atomic bitmap to allocate. +-----------------------------------------------------------------------------*/ +#include "mimalloc.h" +#include "mimalloc/internal.h" +#include "mimalloc/atomic.h" + +#include <string.h> // memset +#include <errno.h> // ENOMEM + +#include "bitmap.h" // atomic bitmap + +/* ----------------------------------------------------------- + Arena allocation +----------------------------------------------------------- */ + +// Block info: bit 0 contains the `in_use` bit, the upper bits the +// size in count of arena blocks. +typedef uintptr_t mi_block_info_t; +#define MI_ARENA_BLOCK_SIZE (MI_SEGMENT_SIZE) // 64MiB (must be at least MI_SEGMENT_ALIGN) +#define MI_ARENA_MIN_OBJ_SIZE (MI_ARENA_BLOCK_SIZE/2) // 32MiB +#define MI_MAX_ARENAS (112) // not more than 126 (since we use 7 bits in the memid and an arena index + 1) + +// A memory arena descriptor +typedef struct mi_arena_s { + mi_arena_id_t id; // arena id; 0 for non-specific + mi_memid_t memid; // memid of the memory area + _Atomic(uint8_t*) start; // the start of the memory area + size_t block_count; // size of the area in arena blocks (of `MI_ARENA_BLOCK_SIZE`) + size_t field_count; // number of bitmap fields (where `field_count * MI_BITMAP_FIELD_BITS >= block_count`) + size_t meta_size; // size of the arena structure itself (including its bitmaps) + mi_memid_t meta_memid; // memid of the arena structure itself (OS or static allocation) + int numa_node; // associated NUMA node + bool exclusive; // only allow allocations if specifically for this arena + bool is_large; // memory area consists of large- or huge OS pages (always committed) + _Atomic(size_t) search_idx; // optimization to start the search for free blocks + _Atomic(mi_msecs_t) purge_expire; // expiration time when blocks should be decommitted from `blocks_decommit`. + mi_bitmap_field_t* blocks_dirty; // are the blocks potentially non-zero? + mi_bitmap_field_t* blocks_committed; // are the blocks committed? (can be NULL for memory that cannot be decommitted) + mi_bitmap_field_t* blocks_purge; // blocks that can be (reset) decommitted. (can be NULL for memory that cannot be (reset) decommitted) + mi_bitmap_field_t blocks_inuse[1]; // in-place bitmap of in-use blocks (of size `field_count`) +} mi_arena_t; + + +// The available arenas +static mi_decl_cache_align _Atomic(mi_arena_t*) mi_arenas[MI_MAX_ARENAS]; +static mi_decl_cache_align _Atomic(size_t) mi_arena_count; // = 0 + + +//static bool mi_manage_os_memory_ex2(void* start, size_t size, bool is_large, int numa_node, bool exclusive, mi_memid_t memid, mi_arena_id_t* arena_id) mi_attr_noexcept; + +/* ----------------------------------------------------------- + Arena id's + id = arena_index + 1 +----------------------------------------------------------- */ + +static size_t mi_arena_id_index(mi_arena_id_t id) { + return (size_t)(id <= 0 ? MI_MAX_ARENAS : id - 1); +} + +static mi_arena_id_t mi_arena_id_create(size_t arena_index) { + mi_assert_internal(arena_index < MI_MAX_ARENAS); + return (int)arena_index + 1; +} + +mi_arena_id_t _mi_arena_id_none(void) { + return 0; +} + +static bool mi_arena_id_is_suitable(mi_arena_id_t arena_id, bool arena_is_exclusive, mi_arena_id_t req_arena_id) { + return ((!arena_is_exclusive && req_arena_id == _mi_arena_id_none()) || + (arena_id == req_arena_id)); +} + +bool _mi_arena_memid_is_suitable(mi_memid_t memid, mi_arena_id_t request_arena_id) { + if (memid.memkind == MI_MEM_ARENA) { + return mi_arena_id_is_suitable(memid.mem.arena.id, memid.mem.arena.is_exclusive, request_arena_id); + } + else { + return mi_arena_id_is_suitable(0, false, request_arena_id); + } +} + +bool _mi_arena_memid_is_os_allocated(mi_memid_t memid) { + return (memid.memkind == MI_MEM_OS); +} + +/* ----------------------------------------------------------- + Arena allocations get a (currently) 16-bit memory id where the + lower 8 bits are the arena id, and the upper bits the block index. +----------------------------------------------------------- */ + +static size_t mi_block_count_of_size(size_t size) { + return _mi_divide_up(size, MI_ARENA_BLOCK_SIZE); +} + +static size_t mi_arena_block_size(size_t bcount) { + return (bcount * MI_ARENA_BLOCK_SIZE); +} + +static size_t mi_arena_size(mi_arena_t* arena) { + return mi_arena_block_size(arena->block_count); +} + +static mi_memid_t mi_memid_create_arena(mi_arena_id_t id, bool is_exclusive, mi_bitmap_index_t bitmap_index) { + mi_memid_t memid = _mi_memid_create(MI_MEM_ARENA); + memid.mem.arena.id = id; + memid.mem.arena.block_index = bitmap_index; + memid.mem.arena.is_exclusive = is_exclusive; + return memid; +} + +static bool mi_arena_memid_indices(mi_memid_t memid, size_t* arena_index, mi_bitmap_index_t* bitmap_index) { + mi_assert_internal(memid.memkind == MI_MEM_ARENA); + *arena_index = mi_arena_id_index(memid.mem.arena.id); + *bitmap_index = memid.mem.arena.block_index; + return memid.mem.arena.is_exclusive; +} + + + +/* ----------------------------------------------------------- + Special static area for mimalloc internal structures + to avoid OS calls (for example, for the arena metadata) +----------------------------------------------------------- */ + +#define MI_ARENA_STATIC_MAX (MI_INTPTR_SIZE*MI_KiB) // 8 KiB on 64-bit + +static uint8_t mi_arena_static[MI_ARENA_STATIC_MAX]; +static _Atomic(size_t) mi_arena_static_top; + +static void* mi_arena_static_zalloc(size_t size, size_t alignment, mi_memid_t* memid) { + *memid = _mi_memid_none(); + if (size == 0 || size > MI_ARENA_STATIC_MAX) return NULL; + if ((mi_atomic_load_relaxed(&mi_arena_static_top) + size) > MI_ARENA_STATIC_MAX) return NULL; + + // try to claim space + if (alignment == 0) { alignment = 1; } + const size_t oversize = size + alignment - 1; + if (oversize > MI_ARENA_STATIC_MAX) return NULL; + const size_t oldtop = mi_atomic_add_acq_rel(&mi_arena_static_top, oversize); + size_t top = oldtop + oversize; + if (top > MI_ARENA_STATIC_MAX) { + // try to roll back, ok if this fails + mi_atomic_cas_strong_acq_rel(&mi_arena_static_top, &top, oldtop); + return NULL; + } + + // success + *memid = _mi_memid_create(MI_MEM_STATIC); + const size_t start = _mi_align_up(oldtop, alignment); + uint8_t* const p = &mi_arena_static[start]; + _mi_memzero(p, size); + return p; +} + +static void* mi_arena_meta_zalloc(size_t size, mi_memid_t* memid, mi_stats_t* stats) { + *memid = _mi_memid_none(); + + // try static + void* p = mi_arena_static_zalloc(size, MI_ALIGNMENT_MAX, memid); + if (p != NULL) return p; + + // or fall back to the OS + return _mi_os_alloc(size, memid, stats); +} + +static void mi_arena_meta_free(void* p, mi_memid_t memid, size_t size, mi_stats_t* stats) { + if (mi_memkind_is_os(memid.memkind)) { + _mi_os_free(p, size, memid, stats); + } + else { + mi_assert(memid.memkind == MI_MEM_STATIC); + } +} + +static void* mi_arena_block_start(mi_arena_t* arena, mi_bitmap_index_t bindex) { + return (arena->start + mi_arena_block_size(mi_bitmap_index_bit(bindex))); +} + + +/* ----------------------------------------------------------- + Thread safe allocation in an arena +----------------------------------------------------------- */ + +// claim the `blocks_inuse` bits +static bool mi_arena_try_claim(mi_arena_t* arena, size_t blocks, mi_bitmap_index_t* bitmap_idx) +{ + size_t idx = 0; // mi_atomic_load_relaxed(&arena->search_idx); // start from last search; ok to be relaxed as the exact start does not matter + if (_mi_bitmap_try_find_from_claim_across(arena->blocks_inuse, arena->field_count, idx, blocks, bitmap_idx)) { + mi_atomic_store_relaxed(&arena->search_idx, mi_bitmap_index_field(*bitmap_idx)); // start search from found location next time around + return true; + }; + return false; +} + + +/* ----------------------------------------------------------- + Arena Allocation +----------------------------------------------------------- */ + +static mi_decl_noinline void* mi_arena_try_alloc_at(mi_arena_t* arena, size_t arena_index, size_t needed_bcount, + bool commit, mi_memid_t* memid, mi_os_tld_t* tld) +{ + MI_UNUSED(arena_index); + mi_assert_internal(mi_arena_id_index(arena->id) == arena_index); + + mi_bitmap_index_t bitmap_index; + if (!mi_arena_try_claim(arena, needed_bcount, &bitmap_index)) return NULL; + + // claimed it! + void* p = mi_arena_block_start(arena, bitmap_index); + *memid = mi_memid_create_arena(arena->id, arena->exclusive, bitmap_index); + memid->is_pinned = arena->memid.is_pinned; + + // none of the claimed blocks should be scheduled for a decommit + if (arena->blocks_purge != NULL) { + // this is thread safe as a potential purge only decommits parts that are not yet claimed as used (in `blocks_inuse`). + _mi_bitmap_unclaim_across(arena->blocks_purge, arena->field_count, needed_bcount, bitmap_index); + } + + // set the dirty bits (todo: no need for an atomic op here?) + if (arena->memid.initially_zero && arena->blocks_dirty != NULL) { + memid->initially_zero = _mi_bitmap_claim_across(arena->blocks_dirty, arena->field_count, needed_bcount, bitmap_index, NULL); + } + + // set commit state + if (arena->blocks_committed == NULL) { + // always committed + memid->initially_committed = true; + } + else if (commit) { + // commit requested, but the range may not be committed as a whole: ensure it is committed now + memid->initially_committed = true; + bool any_uncommitted; + _mi_bitmap_claim_across(arena->blocks_committed, arena->field_count, needed_bcount, bitmap_index, &any_uncommitted); + if (any_uncommitted) { + bool commit_zero = false; + if (!_mi_os_commit(p, mi_arena_block_size(needed_bcount), &commit_zero, tld->stats)) { + memid->initially_committed = false; + } + else { + if (commit_zero) { memid->initially_zero = true; } + } + } + } + else { + // no need to commit, but check if already fully committed + memid->initially_committed = _mi_bitmap_is_claimed_across(arena->blocks_committed, arena->field_count, needed_bcount, bitmap_index); + } + + return p; +} + +// allocate in a speficic arena +static void* mi_arena_try_alloc_at_id(mi_arena_id_t arena_id, bool match_numa_node, int numa_node, size_t size, size_t alignment, + bool commit, bool allow_large, mi_arena_id_t req_arena_id, mi_memid_t* memid, mi_os_tld_t* tld ) +{ + MI_UNUSED_RELEASE(alignment); + mi_assert_internal(alignment <= MI_SEGMENT_ALIGN); + const size_t bcount = mi_block_count_of_size(size); + const size_t arena_index = mi_arena_id_index(arena_id); + mi_assert_internal(arena_index < mi_atomic_load_relaxed(&mi_arena_count)); + mi_assert_internal(size <= mi_arena_block_size(bcount)); + + // Check arena suitability + mi_arena_t* arena = mi_atomic_load_ptr_acquire(mi_arena_t, &mi_arenas[arena_index]); + if (arena == NULL) return NULL; + if (!allow_large && arena->is_large) return NULL; + if (!mi_arena_id_is_suitable(arena->id, arena->exclusive, req_arena_id)) return NULL; + if (req_arena_id == _mi_arena_id_none()) { // in not specific, check numa affinity + const bool numa_suitable = (numa_node < 0 || arena->numa_node < 0 || arena->numa_node == numa_node); + if (match_numa_node) { if (!numa_suitable) return NULL; } + else { if (numa_suitable) return NULL; } + } + + // try to allocate + void* p = mi_arena_try_alloc_at(arena, arena_index, bcount, commit, memid, tld); + mi_assert_internal(p == NULL || _mi_is_aligned(p, alignment)); + return p; +} + + +// allocate from an arena with fallback to the OS +static mi_decl_noinline void* mi_arena_try_alloc(int numa_node, size_t size, size_t alignment, + bool commit, bool allow_large, + mi_arena_id_t req_arena_id, mi_memid_t* memid, mi_os_tld_t* tld ) +{ + MI_UNUSED(alignment); + mi_assert_internal(alignment <= MI_SEGMENT_ALIGN); + const size_t max_arena = mi_atomic_load_relaxed(&mi_arena_count); + if mi_likely(max_arena == 0) return NULL; + + if (req_arena_id != _mi_arena_id_none()) { + // try a specific arena if requested + if (mi_arena_id_index(req_arena_id) < max_arena) { + void* p = mi_arena_try_alloc_at_id(req_arena_id, true, numa_node, size, alignment, commit, allow_large, req_arena_id, memid, tld); + if (p != NULL) return p; + } + } + else { + // try numa affine allocation + for (size_t i = 0; i < max_arena; i++) { + void* p = mi_arena_try_alloc_at_id(mi_arena_id_create(i), true, numa_node, size, alignment, commit, allow_large, req_arena_id, memid, tld); + if (p != NULL) return p; + } + + // try from another numa node instead.. + if (numa_node >= 0) { // if numa_node was < 0 (no specific affinity requested), all arena's have been tried already + for (size_t i = 0; i < max_arena; i++) { + void* p = mi_arena_try_alloc_at_id(mi_arena_id_create(i), false /* only proceed if not numa local */, numa_node, size, alignment, commit, allow_large, req_arena_id, memid, tld); + if (p != NULL) return p; + } + } + } + return NULL; +} + +// try to reserve a fresh arena space +static bool mi_arena_reserve(size_t req_size, bool allow_large, mi_arena_id_t req_arena_id, mi_arena_id_t *arena_id) +{ + if (_mi_preloading()) return false; // use OS only while pre loading + if (req_arena_id != _mi_arena_id_none()) return false; + + const size_t arena_count = mi_atomic_load_acquire(&mi_arena_count); + if (arena_count > (MI_MAX_ARENAS - 4)) return false; + + size_t arena_reserve = mi_option_get_size(mi_option_arena_reserve); + if (arena_reserve == 0) return false; + + if (!_mi_os_has_virtual_reserve()) { + arena_reserve = arena_reserve/4; // be conservative if virtual reserve is not supported (for some embedded systems for example) + } + arena_reserve = _mi_align_up(arena_reserve, MI_ARENA_BLOCK_SIZE); + if (arena_count >= 8 && arena_count <= 128) { + arena_reserve = ((size_t)1<<(arena_count/8)) * arena_reserve; // scale up the arena sizes exponentially + } + if (arena_reserve < req_size) return false; // should be able to at least handle the current allocation size + + // commit eagerly? + bool arena_commit = false; + if (mi_option_get(mi_option_arena_eager_commit) == 2) { arena_commit = _mi_os_has_overcommit(); } + else if (mi_option_get(mi_option_arena_eager_commit) == 1) { arena_commit = true; } + + return (mi_reserve_os_memory_ex(arena_reserve, arena_commit, allow_large, false /* exclusive */, arena_id) == 0); +} + + +void* _mi_arena_alloc_aligned(size_t size, size_t alignment, size_t align_offset, bool commit, bool allow_large, + mi_arena_id_t req_arena_id, mi_memid_t* memid, mi_os_tld_t* tld) +{ + mi_assert_internal(memid != NULL && tld != NULL); + mi_assert_internal(size > 0); + *memid = _mi_memid_none(); + + const int numa_node = _mi_os_numa_node(tld); // current numa node + + // try to allocate in an arena if the alignment is small enough and the object is not too small (as for heap meta data) + if (size >= MI_ARENA_MIN_OBJ_SIZE && alignment <= MI_SEGMENT_ALIGN && align_offset == 0) { + void* p = mi_arena_try_alloc(numa_node, size, alignment, commit, allow_large, req_arena_id, memid, tld); + if (p != NULL) return p; + + // otherwise, try to first eagerly reserve a new arena + if (req_arena_id == _mi_arena_id_none()) { + mi_arena_id_t arena_id = 0; + if (mi_arena_reserve(size, allow_large, req_arena_id, &arena_id)) { + // and try allocate in there + mi_assert_internal(req_arena_id == _mi_arena_id_none()); + p = mi_arena_try_alloc_at_id(arena_id, true, numa_node, size, alignment, commit, allow_large, req_arena_id, memid, tld); + if (p != NULL) return p; + } + } + } + + // if we cannot use OS allocation, return NULL + if (mi_option_is_enabled(mi_option_limit_os_alloc) || req_arena_id != _mi_arena_id_none()) { + errno = ENOMEM; + return NULL; + } + + // finally, fall back to the OS + if (align_offset > 0) { + return _mi_os_alloc_aligned_at_offset(size, alignment, align_offset, commit, allow_large, memid, tld->stats); + } + else { + return _mi_os_alloc_aligned(size, alignment, commit, allow_large, memid, tld->stats); + } +} + +void* _mi_arena_alloc(size_t size, bool commit, bool allow_large, mi_arena_id_t req_arena_id, mi_memid_t* memid, mi_os_tld_t* tld) +{ + return _mi_arena_alloc_aligned(size, MI_ARENA_BLOCK_SIZE, 0, commit, allow_large, req_arena_id, memid, tld); +} + + +void* mi_arena_area(mi_arena_id_t arena_id, size_t* size) { + if (size != NULL) *size = 0; + size_t arena_index = mi_arena_id_index(arena_id); + if (arena_index >= MI_MAX_ARENAS) return NULL; + mi_arena_t* arena = mi_atomic_load_ptr_acquire(mi_arena_t, &mi_arenas[arena_index]); + if (arena == NULL) return NULL; + if (size != NULL) { *size = mi_arena_block_size(arena->block_count); } + return arena->start; +} + + +/* ----------------------------------------------------------- + Arena purge +----------------------------------------------------------- */ + +static long mi_arena_purge_delay(void) { + // <0 = no purging allowed, 0=immediate purging, >0=milli-second delay + return (mi_option_get(mi_option_purge_delay) * mi_option_get(mi_option_arena_purge_mult)); +} + +// reset or decommit in an arena and update the committed/decommit bitmaps +// assumes we own the area (i.e. blocks_in_use is claimed by us) +static void mi_arena_purge(mi_arena_t* arena, size_t bitmap_idx, size_t blocks, mi_stats_t* stats) { + mi_assert_internal(arena->blocks_committed != NULL); + mi_assert_internal(arena->blocks_purge != NULL); + mi_assert_internal(!arena->memid.is_pinned); + const size_t size = mi_arena_block_size(blocks); + void* const p = mi_arena_block_start(arena, bitmap_idx); + bool needs_recommit; + if (_mi_bitmap_is_claimed_across(arena->blocks_committed, arena->field_count, blocks, bitmap_idx)) { + // all blocks are committed, we can purge freely + needs_recommit = _mi_os_purge(p, size, stats); + } + else { + // some blocks are not committed -- this can happen when a partially committed block is freed + // in `_mi_arena_free` and it is conservatively marked as uncommitted but still scheduled for a purge + // we need to ensure we do not try to reset (as that may be invalid for uncommitted memory), + // and also undo the decommit stats (as it was already adjusted) + mi_assert_internal(mi_option_is_enabled(mi_option_purge_decommits)); + needs_recommit = _mi_os_purge_ex(p, size, false /* allow reset? */, stats); + _mi_stat_increase(&stats->committed, size); + } + + // clear the purged blocks + _mi_bitmap_unclaim_across(arena->blocks_purge, arena->field_count, blocks, bitmap_idx); + // update committed bitmap + if (needs_recommit) { + _mi_bitmap_unclaim_across(arena->blocks_committed, arena->field_count, blocks, bitmap_idx); + } +} + +// Schedule a purge. This is usually delayed to avoid repeated decommit/commit calls. +// Note: assumes we (still) own the area as we may purge immediately +static void mi_arena_schedule_purge(mi_arena_t* arena, size_t bitmap_idx, size_t blocks, mi_stats_t* stats) { + mi_assert_internal(arena->blocks_purge != NULL); + const long delay = mi_arena_purge_delay(); + if (delay < 0) return; // is purging allowed at all? + + if (_mi_preloading() || delay == 0) { + // decommit directly + mi_arena_purge(arena, bitmap_idx, blocks, stats); + } + else { + // schedule decommit + mi_msecs_t expire = mi_atomic_loadi64_relaxed(&arena->purge_expire); + if (expire != 0) { + mi_atomic_addi64_acq_rel(&arena->purge_expire, delay/10); // add smallish extra delay + } + else { + mi_atomic_storei64_release(&arena->purge_expire, _mi_clock_now() + delay); + } + _mi_bitmap_claim_across(arena->blocks_purge, arena->field_count, blocks, bitmap_idx, NULL); + } +} + +// purge a range of blocks +// return true if the full range was purged. +// assumes we own the area (i.e. blocks_in_use is claimed by us) +static bool mi_arena_purge_range(mi_arena_t* arena, size_t idx, size_t startidx, size_t bitlen, size_t purge, mi_stats_t* stats) { + const size_t endidx = startidx + bitlen; + size_t bitidx = startidx; + bool all_purged = false; + while (bitidx < endidx) { + // count consequetive ones in the purge mask + size_t count = 0; + while (bitidx + count < endidx && (purge & ((size_t)1 << (bitidx + count))) != 0) { + count++; + } + if (count > 0) { + // found range to be purged + const mi_bitmap_index_t range_idx = mi_bitmap_index_create(idx, bitidx); + mi_arena_purge(arena, range_idx, count, stats); + if (count == bitlen) { + all_purged = true; + } + } + bitidx += (count+1); // +1 to skip the zero bit (or end) + } + return all_purged; +} + +// returns true if anything was purged +static bool mi_arena_try_purge(mi_arena_t* arena, mi_msecs_t now, bool force, mi_stats_t* stats) +{ + if (arena->memid.is_pinned || arena->blocks_purge == NULL) return false; + mi_msecs_t expire = mi_atomic_loadi64_relaxed(&arena->purge_expire); + if (expire == 0) return false; + if (!force && expire > now) return false; + + // reset expire (if not already set concurrently) + mi_atomic_casi64_strong_acq_rel(&arena->purge_expire, &expire, 0); + + // potential purges scheduled, walk through the bitmap + bool any_purged = false; + bool full_purge = true; + for (size_t i = 0; i < arena->field_count; i++) { + size_t purge = mi_atomic_load_relaxed(&arena->blocks_purge[i]); + if (purge != 0) { + size_t bitidx = 0; + while (bitidx < MI_BITMAP_FIELD_BITS) { + // find consequetive range of ones in the purge mask + size_t bitlen = 0; + while (bitidx + bitlen < MI_BITMAP_FIELD_BITS && (purge & ((size_t)1 << (bitidx + bitlen))) != 0) { + bitlen++; + } + // try to claim the longest range of corresponding in_use bits + const mi_bitmap_index_t bitmap_index = mi_bitmap_index_create(i, bitidx); + while( bitlen > 0 ) { + if (_mi_bitmap_try_claim(arena->blocks_inuse, arena->field_count, bitlen, bitmap_index)) { + break; + } + bitlen--; + } + // actual claimed bits at `in_use` + if (bitlen > 0) { + // read purge again now that we have the in_use bits + purge = mi_atomic_load_acquire(&arena->blocks_purge[i]); + if (!mi_arena_purge_range(arena, i, bitidx, bitlen, purge, stats)) { + full_purge = false; + } + any_purged = true; + // release the claimed `in_use` bits again + _mi_bitmap_unclaim(arena->blocks_inuse, arena->field_count, bitlen, bitmap_index); + } + bitidx += (bitlen+1); // +1 to skip the zero (or end) + } // while bitidx + } // purge != 0 + } + // if not fully purged, make sure to purge again in the future + if (!full_purge) { + const long delay = mi_arena_purge_delay(); + mi_msecs_t expected = 0; + mi_atomic_casi64_strong_acq_rel(&arena->purge_expire,&expected,_mi_clock_now() + delay); + } + return any_purged; +} + +static void mi_arenas_try_purge( bool force, bool visit_all, mi_stats_t* stats ) { + if (_mi_preloading() || mi_arena_purge_delay() <= 0) return; // nothing will be scheduled + + const size_t max_arena = mi_atomic_load_acquire(&mi_arena_count); + if (max_arena == 0) return; + + // allow only one thread to purge at a time + static mi_atomic_guard_t purge_guard; + mi_atomic_guard(&purge_guard) + { + mi_msecs_t now = _mi_clock_now(); + size_t max_purge_count = (visit_all ? max_arena : 1); + for (size_t i = 0; i < max_arena; i++) { + mi_arena_t* arena = mi_atomic_load_ptr_acquire(mi_arena_t, &mi_arenas[i]); + if (arena != NULL) { + if (mi_arena_try_purge(arena, now, force, stats)) { + if (max_purge_count <= 1) break; + max_purge_count--; + } + } + } + } +} + + +/* ----------------------------------------------------------- + Arena free +----------------------------------------------------------- */ + +void _mi_arena_free(void* p, size_t size, size_t committed_size, mi_memid_t memid, mi_stats_t* stats) { + mi_assert_internal(size > 0 && stats != NULL); + mi_assert_internal(committed_size <= size); + if (p==NULL) return; + if (size==0) return; + const bool all_committed = (committed_size == size); + + if (mi_memkind_is_os(memid.memkind)) { + // was a direct OS allocation, pass through + if (!all_committed && committed_size > 0) { + // if partially committed, adjust the committed stats (as `_mi_os_free` will increase decommit by the full size) + _mi_stat_decrease(&stats->committed, committed_size); + } + _mi_os_free(p, size, memid, stats); + } + else if (memid.memkind == MI_MEM_ARENA) { + // allocated in an arena + size_t arena_idx; + size_t bitmap_idx; + mi_arena_memid_indices(memid, &arena_idx, &bitmap_idx); + mi_assert_internal(arena_idx < MI_MAX_ARENAS); + mi_arena_t* arena = mi_atomic_load_ptr_acquire(mi_arena_t,&mi_arenas[arena_idx]); + mi_assert_internal(arena != NULL); + const size_t blocks = mi_block_count_of_size(size); + + // checks + if (arena == NULL) { + _mi_error_message(EINVAL, "trying to free from non-existent arena: %p, size %zu, memid: 0x%zx\n", p, size, memid); + return; + } + mi_assert_internal(arena->field_count > mi_bitmap_index_field(bitmap_idx)); + if (arena->field_count <= mi_bitmap_index_field(bitmap_idx)) { + _mi_error_message(EINVAL, "trying to free from non-existent arena block: %p, size %zu, memid: 0x%zx\n", p, size, memid); + return; + } + + // need to set all memory to undefined as some parts may still be marked as no_access (like padding etc.) + mi_track_mem_undefined(p,size); + + // potentially decommit + if (arena->memid.is_pinned || arena->blocks_committed == NULL) { + mi_assert_internal(all_committed); + } + else { + mi_assert_internal(arena->blocks_committed != NULL); + mi_assert_internal(arena->blocks_purge != NULL); + + if (!all_committed) { + // mark the entire range as no longer committed (so we recommit the full range when re-using) + _mi_bitmap_unclaim_across(arena->blocks_committed, arena->field_count, blocks, bitmap_idx); + mi_track_mem_noaccess(p,size); + if (committed_size > 0) { + // if partially committed, adjust the committed stats (is it will be recommitted when re-using) + // in the delayed purge, we now need to not count a decommit if the range is not marked as committed. + _mi_stat_decrease(&stats->committed, committed_size); + } + // note: if not all committed, it may be that the purge will reset/decommit the entire range + // that contains already decommitted parts. Since purge consistently uses reset or decommit that + // works (as we should never reset decommitted parts). + } + // (delay) purge the entire range + mi_arena_schedule_purge(arena, bitmap_idx, blocks, stats); + } + + // and make it available to others again + bool all_inuse = _mi_bitmap_unclaim_across(arena->blocks_inuse, arena->field_count, blocks, bitmap_idx); + if (!all_inuse) { + _mi_error_message(EAGAIN, "trying to free an already freed arena block: %p, size %zu\n", p, size); + return; + }; + } + else { + // arena was none, external, or static; nothing to do + mi_assert_internal(memid.memkind < MI_MEM_OS); + } + + // purge expired decommits + mi_arenas_try_purge(false, false, stats); +} + +// destroy owned arenas; this is unsafe and should only be done using `mi_option_destroy_on_exit` +// for dynamic libraries that are unloaded and need to release all their allocated memory. +static void mi_arenas_unsafe_destroy(void) { + const size_t max_arena = mi_atomic_load_relaxed(&mi_arena_count); + size_t new_max_arena = 0; + for (size_t i = 0; i < max_arena; i++) { + mi_arena_t* arena = mi_atomic_load_ptr_acquire(mi_arena_t, &mi_arenas[i]); + if (arena != NULL) { + if (arena->start != NULL && mi_memkind_is_os(arena->memid.memkind)) { + mi_atomic_store_ptr_release(mi_arena_t, &mi_arenas[i], NULL); + _mi_os_free(arena->start, mi_arena_size(arena), arena->memid, &_mi_stats_main); + } + else { + new_max_arena = i; + } + mi_arena_meta_free(arena, arena->meta_memid, arena->meta_size, &_mi_stats_main); + } + } + + // try to lower the max arena. + size_t expected = max_arena; + mi_atomic_cas_strong_acq_rel(&mi_arena_count, &expected, new_max_arena); +} + +// Purge the arenas; if `force_purge` is true, amenable parts are purged even if not yet expired +void _mi_arena_collect(bool force_purge, mi_stats_t* stats) { + mi_arenas_try_purge(force_purge, true /* visit all */, stats); +} + +// destroy owned arenas; this is unsafe and should only be done using `mi_option_destroy_on_exit` +// for dynamic libraries that are unloaded and need to release all their allocated memory. +void _mi_arena_unsafe_destroy_all(mi_stats_t* stats) { + mi_arenas_unsafe_destroy(); + _mi_arena_collect(true /* force purge */, stats); // purge non-owned arenas +} + +// Is a pointer inside any of our arenas? +bool _mi_arena_contains(const void* p) { + const size_t max_arena = mi_atomic_load_relaxed(&mi_arena_count); + for (size_t i = 0; i < max_arena; i++) { + mi_arena_t* arena = mi_atomic_load_ptr_acquire(mi_arena_t, &mi_arenas[i]); + if (arena != NULL && arena->start <= (const uint8_t*)p && arena->start + mi_arena_block_size(arena->block_count) > (const uint8_t*)p) { + return true; + } + } + return false; +} + + +/* ----------------------------------------------------------- + Add an arena. +----------------------------------------------------------- */ + +static bool mi_arena_add(mi_arena_t* arena, mi_arena_id_t* arena_id) { + mi_assert_internal(arena != NULL); + mi_assert_internal((uintptr_t)mi_atomic_load_ptr_relaxed(uint8_t,&arena->start) % MI_SEGMENT_ALIGN == 0); + mi_assert_internal(arena->block_count > 0); + if (arena_id != NULL) { *arena_id = -1; } + + size_t i = mi_atomic_increment_acq_rel(&mi_arena_count); + if (i >= MI_MAX_ARENAS) { + mi_atomic_decrement_acq_rel(&mi_arena_count); + return false; + } + arena->id = mi_arena_id_create(i); + mi_atomic_store_ptr_release(mi_arena_t,&mi_arenas[i], arena); + if (arena_id != NULL) { *arena_id = arena->id; } + return true; +} + +static bool mi_manage_os_memory_ex2(void* start, size_t size, bool is_large, int numa_node, bool exclusive, mi_memid_t memid, mi_arena_id_t* arena_id) mi_attr_noexcept +{ + if (arena_id != NULL) *arena_id = _mi_arena_id_none(); + if (size < MI_ARENA_BLOCK_SIZE) return false; + + if (is_large) { + mi_assert_internal(memid.initially_committed && memid.is_pinned); + } + + const size_t bcount = size / MI_ARENA_BLOCK_SIZE; + const size_t fields = _mi_divide_up(bcount, MI_BITMAP_FIELD_BITS); + const size_t bitmaps = (memid.is_pinned ? 2 : 4); + const size_t asize = sizeof(mi_arena_t) + (bitmaps*fields*sizeof(mi_bitmap_field_t)); + mi_memid_t meta_memid; + mi_arena_t* arena = (mi_arena_t*)mi_arena_meta_zalloc(asize, &meta_memid, &_mi_stats_main); // TODO: can we avoid allocating from the OS? + if (arena == NULL) return false; + + // already zero'd due to os_alloc + // _mi_memzero(arena, asize); + arena->id = _mi_arena_id_none(); + arena->memid = memid; + arena->exclusive = exclusive; + arena->meta_size = asize; + arena->meta_memid = meta_memid; + arena->block_count = bcount; + arena->field_count = fields; + arena->start = (uint8_t*)start; + arena->numa_node = numa_node; // TODO: or get the current numa node if -1? (now it allows anyone to allocate on -1) + arena->is_large = is_large; + arena->purge_expire = 0; + arena->search_idx = 0; + arena->blocks_dirty = &arena->blocks_inuse[fields]; // just after inuse bitmap + arena->blocks_committed = (arena->memid.is_pinned ? NULL : &arena->blocks_inuse[2*fields]); // just after dirty bitmap + arena->blocks_purge = (arena->memid.is_pinned ? NULL : &arena->blocks_inuse[3*fields]); // just after committed bitmap + // initialize committed bitmap? + if (arena->blocks_committed != NULL && arena->memid.initially_committed) { + memset((void*)arena->blocks_committed, 0xFF, fields*sizeof(mi_bitmap_field_t)); // cast to void* to avoid atomic warning + } + + // and claim leftover blocks if needed (so we never allocate there) + ptrdiff_t post = (fields * MI_BITMAP_FIELD_BITS) - bcount; + mi_assert_internal(post >= 0); + if (post > 0) { + // don't use leftover bits at the end + mi_bitmap_index_t postidx = mi_bitmap_index_create(fields - 1, MI_BITMAP_FIELD_BITS - post); + _mi_bitmap_claim(arena->blocks_inuse, fields, post, postidx, NULL); + } + return mi_arena_add(arena, arena_id); + +} + +bool mi_manage_os_memory_ex(void* start, size_t size, bool is_committed, bool is_large, bool is_zero, int numa_node, bool exclusive, mi_arena_id_t* arena_id) mi_attr_noexcept { + mi_memid_t memid = _mi_memid_create(MI_MEM_EXTERNAL); + memid.initially_committed = is_committed; + memid.initially_zero = is_zero; + memid.is_pinned = is_large; + return mi_manage_os_memory_ex2(start,size,is_large,numa_node,exclusive,memid, arena_id); +} + +// Reserve a range of regular OS memory +int mi_reserve_os_memory_ex(size_t size, bool commit, bool allow_large, bool exclusive, mi_arena_id_t* arena_id) mi_attr_noexcept { + if (arena_id != NULL) *arena_id = _mi_arena_id_none(); + size = _mi_align_up(size, MI_ARENA_BLOCK_SIZE); // at least one block + mi_memid_t memid; + void* start = _mi_os_alloc_aligned(size, MI_SEGMENT_ALIGN, commit, allow_large, &memid, &_mi_stats_main); + if (start == NULL) return ENOMEM; + const bool is_large = memid.is_pinned; // todo: use separate is_large field? + if (!mi_manage_os_memory_ex2(start, size, is_large, -1 /* numa node */, exclusive, memid, arena_id)) { + _mi_os_free_ex(start, size, commit, memid, &_mi_stats_main); + _mi_verbose_message("failed to reserve %zu k memory\n", _mi_divide_up(size, 1024)); + return ENOMEM; + } + _mi_verbose_message("reserved %zu KiB memory%s\n", _mi_divide_up(size, 1024), is_large ? " (in large os pages)" : ""); + return 0; +} + + +// Manage a range of regular OS memory +bool mi_manage_os_memory(void* start, size_t size, bool is_committed, bool is_large, bool is_zero, int numa_node) mi_attr_noexcept { + return mi_manage_os_memory_ex(start, size, is_committed, is_large, is_zero, numa_node, false /* exclusive? */, NULL); +} + +// Reserve a range of regular OS memory +int mi_reserve_os_memory(size_t size, bool commit, bool allow_large) mi_attr_noexcept { + return mi_reserve_os_memory_ex(size, commit, allow_large, false, NULL); +} + + +/* ----------------------------------------------------------- + Debugging +----------------------------------------------------------- */ + +static size_t mi_debug_show_bitmap(const char* prefix, mi_bitmap_field_t* fields, size_t field_count ) { + size_t inuse_count = 0; + for (size_t i = 0; i < field_count; i++) { + char buf[MI_BITMAP_FIELD_BITS + 1]; + uintptr_t field = mi_atomic_load_relaxed(&fields[i]); + for (size_t bit = 0; bit < MI_BITMAP_FIELD_BITS; bit++) { + bool inuse = ((((uintptr_t)1 << bit) & field) != 0); + if (inuse) inuse_count++; + buf[MI_BITMAP_FIELD_BITS - 1 - bit] = (inuse ? 'x' : '.'); + } + buf[MI_BITMAP_FIELD_BITS] = 0; + _mi_verbose_message("%s%s\n", prefix, buf); + } + return inuse_count; +} + +void mi_debug_show_arenas(void) mi_attr_noexcept { + size_t max_arenas = mi_atomic_load_relaxed(&mi_arena_count); + for (size_t i = 0; i < max_arenas; i++) { + mi_arena_t* arena = mi_atomic_load_ptr_relaxed(mi_arena_t, &mi_arenas[i]); + if (arena == NULL) break; + size_t inuse_count = 0; + _mi_verbose_message("arena %zu: %zu blocks with %zu fields\n", i, arena->block_count, arena->field_count); + inuse_count += mi_debug_show_bitmap(" ", arena->blocks_inuse, arena->field_count); + _mi_verbose_message(" blocks in use ('x'): %zu\n", inuse_count); + } +} + + +/* ----------------------------------------------------------- + Reserve a huge page arena. +----------------------------------------------------------- */ +// reserve at a specific numa node +int mi_reserve_huge_os_pages_at_ex(size_t pages, int numa_node, size_t timeout_msecs, bool exclusive, mi_arena_id_t* arena_id) mi_attr_noexcept { + if (arena_id != NULL) *arena_id = -1; + if (pages==0) return 0; + if (numa_node < -1) numa_node = -1; + if (numa_node >= 0) numa_node = numa_node % _mi_os_numa_node_count(); + size_t hsize = 0; + size_t pages_reserved = 0; + mi_memid_t memid; + void* p = _mi_os_alloc_huge_os_pages(pages, numa_node, timeout_msecs, &pages_reserved, &hsize, &memid); + if (p==NULL || pages_reserved==0) { + _mi_warning_message("failed to reserve %zu GiB huge pages\n", pages); + return ENOMEM; + } + _mi_verbose_message("numa node %i: reserved %zu GiB huge pages (of the %zu GiB requested)\n", numa_node, pages_reserved, pages); + + if (!mi_manage_os_memory_ex2(p, hsize, true, numa_node, exclusive, memid, arena_id)) { + _mi_os_free(p, hsize, memid, &_mi_stats_main); + return ENOMEM; + } + return 0; +} + +int mi_reserve_huge_os_pages_at(size_t pages, int numa_node, size_t timeout_msecs) mi_attr_noexcept { + return mi_reserve_huge_os_pages_at_ex(pages, numa_node, timeout_msecs, false, NULL); +} + +// reserve huge pages evenly among the given number of numa nodes (or use the available ones as detected) +int mi_reserve_huge_os_pages_interleave(size_t pages, size_t numa_nodes, size_t timeout_msecs) mi_attr_noexcept { + if (pages == 0) return 0; + + // pages per numa node + size_t numa_count = (numa_nodes > 0 ? numa_nodes : _mi_os_numa_node_count()); + if (numa_count <= 0) numa_count = 1; + const size_t pages_per = pages / numa_count; + const size_t pages_mod = pages % numa_count; + const size_t timeout_per = (timeout_msecs==0 ? 0 : (timeout_msecs / numa_count) + 50); + + // reserve evenly among numa nodes + for (size_t numa_node = 0; numa_node < numa_count && pages > 0; numa_node++) { + size_t node_pages = pages_per; // can be 0 + if (numa_node < pages_mod) node_pages++; + int err = mi_reserve_huge_os_pages_at(node_pages, (int)numa_node, timeout_per); + if (err) return err; + if (pages < node_pages) { + pages = 0; + } + else { + pages -= node_pages; + } + } + + return 0; +} + +int mi_reserve_huge_os_pages(size_t pages, double max_secs, size_t* pages_reserved) mi_attr_noexcept { + MI_UNUSED(max_secs); + _mi_warning_message("mi_reserve_huge_os_pages is deprecated: use mi_reserve_huge_os_pages_interleave/at instead\n"); + if (pages_reserved != NULL) *pages_reserved = 0; + int err = mi_reserve_huge_os_pages_interleave(pages, 0, (size_t)(max_secs * 1000.0)); + if (err==0 && pages_reserved!=NULL) *pages_reserved = pages; + return err; +} + |