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Diffstat (limited to 'Objects/mimalloc/os.c')
| -rw-r--r-- | Objects/mimalloc/os.c | 690 |
1 files changed, 690 insertions, 0 deletions
diff --git a/Objects/mimalloc/os.c b/Objects/mimalloc/os.c new file mode 100644 index 0000000..f3bc718 --- /dev/null +++ b/Objects/mimalloc/os.c @@ -0,0 +1,690 @@ +/* ---------------------------------------------------------------------------- +Copyright (c) 2018-2023, 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. +-----------------------------------------------------------------------------*/ +#include "mimalloc.h" +#include "mimalloc/internal.h" +#include "mimalloc/atomic.h" +#include "mimalloc/prim.h" + + +/* ----------------------------------------------------------- + Initialization. + On windows initializes support for aligned allocation and + large OS pages (if MIMALLOC_LARGE_OS_PAGES is true). +----------------------------------------------------------- */ + +static mi_os_mem_config_t mi_os_mem_config = { + 4096, // page size + 0, // large page size (usually 2MiB) + 4096, // allocation granularity + true, // has overcommit? (if true we use MAP_NORESERVE on mmap systems) + false, // must free whole? (on mmap systems we can free anywhere in a mapped range, but on Windows we must free the entire span) + true // has virtual reserve? (if true we can reserve virtual address space without using commit or physical memory) +}; + +bool _mi_os_has_overcommit(void) { + return mi_os_mem_config.has_overcommit; +} + +bool _mi_os_has_virtual_reserve(void) { + return mi_os_mem_config.has_virtual_reserve; +} + + +// OS (small) page size +size_t _mi_os_page_size(void) { + return mi_os_mem_config.page_size; +} + +// if large OS pages are supported (2 or 4MiB), then return the size, otherwise return the small page size (4KiB) +size_t _mi_os_large_page_size(void) { + return (mi_os_mem_config.large_page_size != 0 ? mi_os_mem_config.large_page_size : _mi_os_page_size()); +} + +bool _mi_os_use_large_page(size_t size, size_t alignment) { + // if we have access, check the size and alignment requirements + if (mi_os_mem_config.large_page_size == 0 || !mi_option_is_enabled(mi_option_allow_large_os_pages)) return false; + return ((size % mi_os_mem_config.large_page_size) == 0 && (alignment % mi_os_mem_config.large_page_size) == 0); +} + +// round to a good OS allocation size (bounded by max 12.5% waste) +size_t _mi_os_good_alloc_size(size_t size) { + size_t align_size; + if (size < 512*MI_KiB) align_size = _mi_os_page_size(); + else if (size < 2*MI_MiB) align_size = 64*MI_KiB; + else if (size < 8*MI_MiB) align_size = 256*MI_KiB; + else if (size < 32*MI_MiB) align_size = 1*MI_MiB; + else align_size = 4*MI_MiB; + if mi_unlikely(size >= (SIZE_MAX - align_size)) return size; // possible overflow? + return _mi_align_up(size, align_size); +} + +void _mi_os_init(void) { + _mi_prim_mem_init(&mi_os_mem_config); +} + + +/* ----------------------------------------------------------- + Util +-------------------------------------------------------------- */ +bool _mi_os_decommit(void* addr, size_t size, mi_stats_t* stats); +bool _mi_os_commit(void* addr, size_t size, bool* is_zero, mi_stats_t* tld_stats); + +static void* mi_align_up_ptr(void* p, size_t alignment) { + return (void*)_mi_align_up((uintptr_t)p, alignment); +} + +static void* mi_align_down_ptr(void* p, size_t alignment) { + return (void*)_mi_align_down((uintptr_t)p, alignment); +} + + +/* ----------------------------------------------------------- + aligned hinting +-------------------------------------------------------------- */ + +// On 64-bit systems, we can do efficient aligned allocation by using +// the 2TiB to 30TiB area to allocate those. +#if (MI_INTPTR_SIZE >= 8) +static mi_decl_cache_align _Atomic(uintptr_t)aligned_base; + +// Return a MI_SEGMENT_SIZE aligned address that is probably available. +// If this returns NULL, the OS will determine the address but on some OS's that may not be +// properly aligned which can be more costly as it needs to be adjusted afterwards. +// For a size > 1GiB this always returns NULL in order to guarantee good ASLR randomization; +// (otherwise an initial large allocation of say 2TiB has a 50% chance to include (known) addresses +// in the middle of the 2TiB - 6TiB address range (see issue #372)) + +#define MI_HINT_BASE ((uintptr_t)2 << 40) // 2TiB start +#define MI_HINT_AREA ((uintptr_t)4 << 40) // upto 6TiB (since before win8 there is "only" 8TiB available to processes) +#define MI_HINT_MAX ((uintptr_t)30 << 40) // wrap after 30TiB (area after 32TiB is used for huge OS pages) + +void* _mi_os_get_aligned_hint(size_t try_alignment, size_t size) +{ + if (try_alignment <= 1 || try_alignment > MI_SEGMENT_SIZE) return NULL; + size = _mi_align_up(size, MI_SEGMENT_SIZE); + if (size > 1*MI_GiB) return NULL; // guarantee the chance of fixed valid address is at most 1/(MI_HINT_AREA / 1<<30) = 1/4096. + #if (MI_SECURE>0) + size += MI_SEGMENT_SIZE; // put in `MI_SEGMENT_SIZE` virtual gaps between hinted blocks; this splits VLA's but increases guarded areas. + #endif + + uintptr_t hint = mi_atomic_add_acq_rel(&aligned_base, size); + if (hint == 0 || hint > MI_HINT_MAX) { // wrap or initialize + uintptr_t init = MI_HINT_BASE; + #if (MI_SECURE>0 || MI_DEBUG==0) // security: randomize start of aligned allocations unless in debug mode + uintptr_t r = _mi_heap_random_next(mi_prim_get_default_heap()); + init = init + ((MI_SEGMENT_SIZE * ((r>>17) & 0xFFFFF)) % MI_HINT_AREA); // (randomly 20 bits)*4MiB == 0 to 4TiB + #endif + uintptr_t expected = hint + size; + mi_atomic_cas_strong_acq_rel(&aligned_base, &expected, init); + hint = mi_atomic_add_acq_rel(&aligned_base, size); // this may still give 0 or > MI_HINT_MAX but that is ok, it is a hint after all + } + if (hint%try_alignment != 0) return NULL; + return (void*)hint; +} +#else +void* _mi_os_get_aligned_hint(size_t try_alignment, size_t size) { + MI_UNUSED(try_alignment); MI_UNUSED(size); + return NULL; +} +#endif + + +/* ----------------------------------------------------------- + Free memory +-------------------------------------------------------------- */ + +static void mi_os_free_huge_os_pages(void* p, size_t size, mi_stats_t* stats); + +static void mi_os_prim_free(void* addr, size_t size, bool still_committed, mi_stats_t* tld_stats) { + MI_UNUSED(tld_stats); + mi_assert_internal((size % _mi_os_page_size()) == 0); + if (addr == NULL || size == 0) return; // || _mi_os_is_huge_reserved(addr) + int err = _mi_prim_free(addr, size); + if (err != 0) { + _mi_warning_message("unable to free OS memory (error: %d (0x%x), size: 0x%zx bytes, address: %p)\n", err, err, size, addr); + } + mi_stats_t* stats = &_mi_stats_main; + if (still_committed) { _mi_stat_decrease(&stats->committed, size); } + _mi_stat_decrease(&stats->reserved, size); +} + +void _mi_os_free_ex(void* addr, size_t size, bool still_committed, mi_memid_t memid, mi_stats_t* tld_stats) { + if (mi_memkind_is_os(memid.memkind)) { + size_t csize = _mi_os_good_alloc_size(size); + void* base = addr; + // different base? (due to alignment) + if (memid.mem.os.base != NULL) { + mi_assert(memid.mem.os.base <= addr); + mi_assert((uint8_t*)memid.mem.os.base + memid.mem.os.alignment >= (uint8_t*)addr); + base = memid.mem.os.base; + csize += ((uint8_t*)addr - (uint8_t*)memid.mem.os.base); + } + // free it + if (memid.memkind == MI_MEM_OS_HUGE) { + mi_assert(memid.is_pinned); + mi_os_free_huge_os_pages(base, csize, tld_stats); + } + else { + mi_os_prim_free(base, csize, still_committed, tld_stats); + } + } + else { + // nothing to do + mi_assert(memid.memkind < MI_MEM_OS); + } +} + +void _mi_os_free(void* p, size_t size, mi_memid_t memid, mi_stats_t* tld_stats) { + _mi_os_free_ex(p, size, true, memid, tld_stats); +} + + +/* ----------------------------------------------------------- + Primitive allocation from the OS. +-------------------------------------------------------------- */ + +// Note: the `try_alignment` is just a hint and the returned pointer is not guaranteed to be aligned. +static void* mi_os_prim_alloc(size_t size, size_t try_alignment, bool commit, bool allow_large, bool* is_large, bool* is_zero, mi_stats_t* stats) { + mi_assert_internal(size > 0 && (size % _mi_os_page_size()) == 0); + mi_assert_internal(is_zero != NULL); + mi_assert_internal(is_large != NULL); + if (size == 0) return NULL; + if (!commit) { allow_large = false; } + if (try_alignment == 0) { try_alignment = 1; } // avoid 0 to ensure there will be no divide by zero when aligning + + *is_zero = false; + void* p = NULL; + int err = _mi_prim_alloc(size, try_alignment, commit, allow_large, is_large, is_zero, &p); + if (err != 0) { + _mi_warning_message("unable to allocate OS memory (error: %d (0x%x), size: 0x%zx bytes, align: 0x%zx, commit: %d, allow large: %d)\n", err, err, size, try_alignment, commit, allow_large); + } + mi_stat_counter_increase(stats->mmap_calls, 1); + if (p != NULL) { + _mi_stat_increase(&stats->reserved, size); + if (commit) { + _mi_stat_increase(&stats->committed, size); + // seems needed for asan (or `mimalloc-test-api` fails) + #ifdef MI_TRACK_ASAN + if (*is_zero) { mi_track_mem_defined(p,size); } + else { mi_track_mem_undefined(p,size); } + #endif + } + } + return p; +} + + +// Primitive aligned allocation from the OS. +// This function guarantees the allocated memory is aligned. +static void* mi_os_prim_alloc_aligned(size_t size, size_t alignment, bool commit, bool allow_large, bool* is_large, bool* is_zero, void** base, mi_stats_t* stats) { + mi_assert_internal(alignment >= _mi_os_page_size() && ((alignment & (alignment - 1)) == 0)); + mi_assert_internal(size > 0 && (size % _mi_os_page_size()) == 0); + mi_assert_internal(is_large != NULL); + mi_assert_internal(is_zero != NULL); + mi_assert_internal(base != NULL); + if (!commit) allow_large = false; + if (!(alignment >= _mi_os_page_size() && ((alignment & (alignment - 1)) == 0))) return NULL; + size = _mi_align_up(size, _mi_os_page_size()); + + // try first with a hint (this will be aligned directly on Win 10+ or BSD) + void* p = mi_os_prim_alloc(size, alignment, commit, allow_large, is_large, is_zero, stats); + if (p == NULL) return NULL; + + // aligned already? + if (((uintptr_t)p % alignment) == 0) { + *base = p; + } + else { + // if not aligned, free it, overallocate, and unmap around it + // NOTE(sgross): this warning causes issues in Python tests + // _mi_warning_message("unable to allocate aligned OS memory directly, fall back to over-allocation (size: 0x%zx bytes, address: %p, alignment: 0x%zx, commit: %d)\n", size, p, alignment, commit); + mi_os_prim_free(p, size, commit, stats); + if (size >= (SIZE_MAX - alignment)) return NULL; // overflow + const size_t over_size = size + alignment; + + if (mi_os_mem_config.must_free_whole) { // win32 virtualAlloc cannot free parts of an allocate block + // over-allocate uncommitted (virtual) memory + p = mi_os_prim_alloc(over_size, 1 /*alignment*/, false /* commit? */, false /* allow_large */, is_large, is_zero, stats); + if (p == NULL) return NULL; + + // set p to the aligned part in the full region + // note: this is dangerous on Windows as VirtualFree needs the actual base pointer + // this is handled though by having the `base` field in the memid's + *base = p; // remember the base + p = mi_align_up_ptr(p, alignment); + + // explicitly commit only the aligned part + if (commit) { + _mi_os_commit(p, size, NULL, stats); + } + } + else { // mmap can free inside an allocation + // overallocate... + p = mi_os_prim_alloc(over_size, 1, commit, false, is_large, is_zero, stats); + if (p == NULL) return NULL; + + // and selectively unmap parts around the over-allocated area. (noop on sbrk) + void* aligned_p = mi_align_up_ptr(p, alignment); + size_t pre_size = (uint8_t*)aligned_p - (uint8_t*)p; + size_t mid_size = _mi_align_up(size, _mi_os_page_size()); + size_t post_size = over_size - pre_size - mid_size; + mi_assert_internal(pre_size < over_size&& post_size < over_size&& mid_size >= size); + if (pre_size > 0) { mi_os_prim_free(p, pre_size, commit, stats); } + if (post_size > 0) { mi_os_prim_free((uint8_t*)aligned_p + mid_size, post_size, commit, stats); } + // we can return the aligned pointer on `mmap` (and sbrk) systems + p = aligned_p; + *base = aligned_p; // since we freed the pre part, `*base == p`. + } + } + + mi_assert_internal(p == NULL || (p != NULL && *base != NULL && ((uintptr_t)p % alignment) == 0)); + return p; +} + + +/* ----------------------------------------------------------- + OS API: alloc and alloc_aligned +----------------------------------------------------------- */ + +void* _mi_os_alloc(size_t size, mi_memid_t* memid, mi_stats_t* tld_stats) { + MI_UNUSED(tld_stats); + *memid = _mi_memid_none(); + mi_stats_t* stats = &_mi_stats_main; + if (size == 0) return NULL; + size = _mi_os_good_alloc_size(size); + bool os_is_large = false; + bool os_is_zero = false; + void* p = mi_os_prim_alloc(size, 0, true, false, &os_is_large, &os_is_zero, stats); + if (p != NULL) { + *memid = _mi_memid_create_os(true, os_is_zero, os_is_large); + } + return p; +} + +void* _mi_os_alloc_aligned(size_t size, size_t alignment, bool commit, bool allow_large, mi_memid_t* memid, mi_stats_t* tld_stats) +{ + MI_UNUSED(&_mi_os_get_aligned_hint); // suppress unused warnings + MI_UNUSED(tld_stats); + *memid = _mi_memid_none(); + if (size == 0) return NULL; + size = _mi_os_good_alloc_size(size); + alignment = _mi_align_up(alignment, _mi_os_page_size()); + + bool os_is_large = false; + bool os_is_zero = false; + void* os_base = NULL; + void* p = mi_os_prim_alloc_aligned(size, alignment, commit, allow_large, &os_is_large, &os_is_zero, &os_base, &_mi_stats_main /*tld->stats*/ ); + if (p != NULL) { + *memid = _mi_memid_create_os(commit, os_is_zero, os_is_large); + memid->mem.os.base = os_base; + memid->mem.os.alignment = alignment; + } + return p; +} + +/* ----------------------------------------------------------- + OS aligned allocation with an offset. This is used + for large alignments > MI_ALIGNMENT_MAX. We use a large mimalloc + page where the object can be aligned at an offset from the start of the segment. + As we may need to overallocate, we need to free such pointers using `mi_free_aligned` + to use the actual start of the memory region. +----------------------------------------------------------- */ + +void* _mi_os_alloc_aligned_at_offset(size_t size, size_t alignment, size_t offset, bool commit, bool allow_large, mi_memid_t* memid, mi_stats_t* tld_stats) { + mi_assert(offset <= MI_SEGMENT_SIZE); + mi_assert(offset <= size); + mi_assert((alignment % _mi_os_page_size()) == 0); + *memid = _mi_memid_none(); + if (offset > MI_SEGMENT_SIZE) return NULL; + if (offset == 0) { + // regular aligned allocation + return _mi_os_alloc_aligned(size, alignment, commit, allow_large, memid, tld_stats); + } + else { + // overallocate to align at an offset + const size_t extra = _mi_align_up(offset, alignment) - offset; + const size_t oversize = size + extra; + void* const start = _mi_os_alloc_aligned(oversize, alignment, commit, allow_large, memid, tld_stats); + if (start == NULL) return NULL; + + void* const p = (uint8_t*)start + extra; + mi_assert(_mi_is_aligned((uint8_t*)p + offset, alignment)); + // decommit the overallocation at the start + if (commit && extra > _mi_os_page_size()) { + _mi_os_decommit(start, extra, tld_stats); + } + return p; + } +} + +/* ----------------------------------------------------------- + OS memory API: reset, commit, decommit, protect, unprotect. +----------------------------------------------------------- */ + +// OS page align within a given area, either conservative (pages inside the area only), +// or not (straddling pages outside the area is possible) +static void* mi_os_page_align_areax(bool conservative, void* addr, size_t size, size_t* newsize) { + mi_assert(addr != NULL && size > 0); + if (newsize != NULL) *newsize = 0; + if (size == 0 || addr == NULL) return NULL; + + // page align conservatively within the range + void* start = (conservative ? mi_align_up_ptr(addr, _mi_os_page_size()) + : mi_align_down_ptr(addr, _mi_os_page_size())); + void* end = (conservative ? mi_align_down_ptr((uint8_t*)addr + size, _mi_os_page_size()) + : mi_align_up_ptr((uint8_t*)addr + size, _mi_os_page_size())); + ptrdiff_t diff = (uint8_t*)end - (uint8_t*)start; + if (diff <= 0) return NULL; + + mi_assert_internal((conservative && (size_t)diff <= size) || (!conservative && (size_t)diff >= size)); + if (newsize != NULL) *newsize = (size_t)diff; + return start; +} + +static void* mi_os_page_align_area_conservative(void* addr, size_t size, size_t* newsize) { + return mi_os_page_align_areax(true, addr, size, newsize); +} + +bool _mi_os_commit(void* addr, size_t size, bool* is_zero, mi_stats_t* tld_stats) { + MI_UNUSED(tld_stats); + mi_stats_t* stats = &_mi_stats_main; + if (is_zero != NULL) { *is_zero = false; } + _mi_stat_increase(&stats->committed, size); // use size for precise commit vs. decommit + _mi_stat_counter_increase(&stats->commit_calls, 1); + + // page align range + size_t csize; + void* start = mi_os_page_align_areax(false /* conservative? */, addr, size, &csize); + if (csize == 0) return true; + + // commit + bool os_is_zero = false; + int err = _mi_prim_commit(start, csize, &os_is_zero); + if (err != 0) { + _mi_warning_message("cannot commit OS memory (error: %d (0x%x), address: %p, size: 0x%zx bytes)\n", err, err, start, csize); + return false; + } + if (os_is_zero && is_zero != NULL) { + *is_zero = true; + mi_assert_expensive(mi_mem_is_zero(start, csize)); + } + // note: the following seems required for asan (otherwise `mimalloc-test-stress` fails) + #ifdef MI_TRACK_ASAN + if (os_is_zero) { mi_track_mem_defined(start,csize); } + else { mi_track_mem_undefined(start,csize); } + #endif + return true; +} + +static bool mi_os_decommit_ex(void* addr, size_t size, bool* needs_recommit, mi_stats_t* tld_stats) { + MI_UNUSED(tld_stats); + mi_stats_t* stats = &_mi_stats_main; + mi_assert_internal(needs_recommit!=NULL); + _mi_stat_decrease(&stats->committed, size); + + // page align + size_t csize; + void* start = mi_os_page_align_area_conservative(addr, size, &csize); + if (csize == 0) return true; + + // decommit + *needs_recommit = true; + int err = _mi_prim_decommit(start,csize,needs_recommit); + if (err != 0) { + _mi_warning_message("cannot decommit OS memory (error: %d (0x%x), address: %p, size: 0x%zx bytes)\n", err, err, start, csize); + } + mi_assert_internal(err == 0); + return (err == 0); +} + +bool _mi_os_decommit(void* addr, size_t size, mi_stats_t* tld_stats) { + bool needs_recommit; + return mi_os_decommit_ex(addr, size, &needs_recommit, tld_stats); +} + + +// Signal to the OS that the address range is no longer in use +// but may be used later again. This will release physical memory +// pages and reduce swapping while keeping the memory committed. +// We page align to a conservative area inside the range to reset. +bool _mi_os_reset(void* addr, size_t size, mi_stats_t* stats) { + // page align conservatively within the range + size_t csize; + void* start = mi_os_page_align_area_conservative(addr, size, &csize); + if (csize == 0) return true; // || _mi_os_is_huge_reserved(addr) + _mi_stat_increase(&stats->reset, csize); + _mi_stat_counter_increase(&stats->reset_calls, 1); + + #if (MI_DEBUG>1) && !MI_SECURE && !MI_TRACK_ENABLED // && !MI_TSAN + memset(start, 0, csize); // pretend it is eagerly reset + #endif + + int err = _mi_prim_reset(start, csize); + if (err != 0) { + _mi_warning_message("cannot reset OS memory (error: %d (0x%x), address: %p, size: 0x%zx bytes)\n", err, err, start, csize); + } + return (err == 0); +} + + +// either resets or decommits memory, returns true if the memory needs +// to be recommitted if it is to be re-used later on. +bool _mi_os_purge_ex(void* p, size_t size, bool allow_reset, mi_stats_t* stats) +{ + if (mi_option_get(mi_option_purge_delay) < 0) return false; // is purging allowed? + _mi_stat_counter_increase(&stats->purge_calls, 1); + _mi_stat_increase(&stats->purged, size); + + if (mi_option_is_enabled(mi_option_purge_decommits) && // should decommit? + !_mi_preloading()) // don't decommit during preloading (unsafe) + { + bool needs_recommit = true; + mi_os_decommit_ex(p, size, &needs_recommit, stats); + return needs_recommit; + } + else { + if (allow_reset) { // this can sometimes be not allowed if the range is not fully committed + _mi_os_reset(p, size, stats); + } + return false; // needs no recommit + } +} + +// either resets or decommits memory, returns true if the memory needs +// to be recommitted if it is to be re-used later on. +bool _mi_os_purge(void* p, size_t size, mi_stats_t * stats) { + return _mi_os_purge_ex(p, size, true, stats); +} + +// Protect a region in memory to be not accessible. +static bool mi_os_protectx(void* addr, size_t size, bool protect) { + // page align conservatively within the range + size_t csize = 0; + void* start = mi_os_page_align_area_conservative(addr, size, &csize); + if (csize == 0) return false; + /* + if (_mi_os_is_huge_reserved(addr)) { + _mi_warning_message("cannot mprotect memory allocated in huge OS pages\n"); + } + */ + int err = _mi_prim_protect(start,csize,protect); + if (err != 0) { + _mi_warning_message("cannot %s OS memory (error: %d (0x%x), address: %p, size: 0x%zx bytes)\n", (protect ? "protect" : "unprotect"), err, err, start, csize); + } + return (err == 0); +} + +bool _mi_os_protect(void* addr, size_t size) { + return mi_os_protectx(addr, size, true); +} + +bool _mi_os_unprotect(void* addr, size_t size) { + return mi_os_protectx(addr, size, false); +} + + + +/* ---------------------------------------------------------------------------- +Support for allocating huge OS pages (1Gib) that are reserved up-front +and possibly associated with a specific NUMA node. (use `numa_node>=0`) +-----------------------------------------------------------------------------*/ +#define MI_HUGE_OS_PAGE_SIZE (MI_GiB) + + +#if (MI_INTPTR_SIZE >= 8) +// To ensure proper alignment, use our own area for huge OS pages +static mi_decl_cache_align _Atomic(uintptr_t) mi_huge_start; // = 0 + +// Claim an aligned address range for huge pages +static uint8_t* mi_os_claim_huge_pages(size_t pages, size_t* total_size) { + if (total_size != NULL) *total_size = 0; + const size_t size = pages * MI_HUGE_OS_PAGE_SIZE; + + uintptr_t start = 0; + uintptr_t end = 0; + uintptr_t huge_start = mi_atomic_load_relaxed(&mi_huge_start); + do { + start = huge_start; + if (start == 0) { + // Initialize the start address after the 32TiB area + start = ((uintptr_t)32 << 40); // 32TiB virtual start address + #if (MI_SECURE>0 || MI_DEBUG==0) // security: randomize start of huge pages unless in debug mode + uintptr_t r = _mi_heap_random_next(mi_prim_get_default_heap()); + start = start + ((uintptr_t)MI_HUGE_OS_PAGE_SIZE * ((r>>17) & 0x0FFF)); // (randomly 12bits)*1GiB == between 0 to 4TiB + #endif + } + end = start + size; + mi_assert_internal(end % MI_SEGMENT_SIZE == 0); + } while (!mi_atomic_cas_strong_acq_rel(&mi_huge_start, &huge_start, end)); + + if (total_size != NULL) *total_size = size; + return (uint8_t*)start; +} +#else +static uint8_t* mi_os_claim_huge_pages(size_t pages, size_t* total_size) { + MI_UNUSED(pages); + if (total_size != NULL) *total_size = 0; + return NULL; +} +#endif + +// Allocate MI_SEGMENT_SIZE aligned huge pages +void* _mi_os_alloc_huge_os_pages(size_t pages, int numa_node, mi_msecs_t max_msecs, size_t* pages_reserved, size_t* psize, mi_memid_t* memid) { + *memid = _mi_memid_none(); + if (psize != NULL) *psize = 0; + if (pages_reserved != NULL) *pages_reserved = 0; + size_t size = 0; + uint8_t* start = mi_os_claim_huge_pages(pages, &size); + if (start == NULL) return NULL; // or 32-bit systems + + // Allocate one page at the time but try to place them contiguously + // We allocate one page at the time to be able to abort if it takes too long + // or to at least allocate as many as available on the system. + mi_msecs_t start_t = _mi_clock_start(); + size_t page = 0; + bool all_zero = true; + while (page < pages) { + // allocate a page + bool is_zero = false; + void* addr = start + (page * MI_HUGE_OS_PAGE_SIZE); + void* p = NULL; + int err = _mi_prim_alloc_huge_os_pages(addr, MI_HUGE_OS_PAGE_SIZE, numa_node, &is_zero, &p); + if (!is_zero) { all_zero = false; } + if (err != 0) { + _mi_warning_message("unable to allocate huge OS page (error: %d (0x%x), address: %p, size: %zx bytes)\n", err, err, addr, MI_HUGE_OS_PAGE_SIZE); + break; + } + + // Did we succeed at a contiguous address? + if (p != addr) { + // no success, issue a warning and break + if (p != NULL) { + _mi_warning_message("could not allocate contiguous huge OS page %zu at %p\n", page, addr); + mi_os_prim_free(p, MI_HUGE_OS_PAGE_SIZE, true, &_mi_stats_main); + } + break; + } + + // success, record it + page++; // increase before timeout check (see issue #711) + _mi_stat_increase(&_mi_stats_main.committed, MI_HUGE_OS_PAGE_SIZE); + _mi_stat_increase(&_mi_stats_main.reserved, MI_HUGE_OS_PAGE_SIZE); + + // check for timeout + if (max_msecs > 0) { + mi_msecs_t elapsed = _mi_clock_end(start_t); + if (page >= 1) { + mi_msecs_t estimate = ((elapsed / (page+1)) * pages); + if (estimate > 2*max_msecs) { // seems like we are going to timeout, break + elapsed = max_msecs + 1; + } + } + if (elapsed > max_msecs) { + _mi_warning_message("huge OS page allocation timed out (after allocating %zu page(s))\n", page); + break; + } + } + } + mi_assert_internal(page*MI_HUGE_OS_PAGE_SIZE <= size); + if (pages_reserved != NULL) { *pages_reserved = page; } + if (psize != NULL) { *psize = page * MI_HUGE_OS_PAGE_SIZE; } + if (page != 0) { + mi_assert(start != NULL); + *memid = _mi_memid_create_os(true /* is committed */, all_zero, true /* is_large */); + memid->memkind = MI_MEM_OS_HUGE; + mi_assert(memid->is_pinned); + #ifdef MI_TRACK_ASAN + if (all_zero) { mi_track_mem_defined(start,size); } + #endif + } + return (page == 0 ? NULL : start); +} + +// free every huge page in a range individually (as we allocated per page) +// note: needed with VirtualAlloc but could potentially be done in one go on mmap'd systems. +static void mi_os_free_huge_os_pages(void* p, size_t size, mi_stats_t* stats) { + if (p==NULL || size==0) return; + uint8_t* base = (uint8_t*)p; + while (size >= MI_HUGE_OS_PAGE_SIZE) { + mi_os_prim_free(base, MI_HUGE_OS_PAGE_SIZE, true, stats); + size -= MI_HUGE_OS_PAGE_SIZE; + base += MI_HUGE_OS_PAGE_SIZE; + } +} + +/* ---------------------------------------------------------------------------- +Support NUMA aware allocation +-----------------------------------------------------------------------------*/ + +_Atomic(size_t) _mi_numa_node_count; // = 0 // cache the node count + +size_t _mi_os_numa_node_count_get(void) { + size_t count = mi_atomic_load_acquire(&_mi_numa_node_count); + if (count <= 0) { + long ncount = mi_option_get(mi_option_use_numa_nodes); // given explicitly? + if (ncount > 0) { + count = (size_t)ncount; + } + else { + count = _mi_prim_numa_node_count(); // or detect dynamically + if (count == 0) count = 1; + } + mi_atomic_store_release(&_mi_numa_node_count, count); // save it + _mi_verbose_message("using %zd numa regions\n", count); + } + return count; +} + +int _mi_os_numa_node_get(mi_os_tld_t* tld) { + MI_UNUSED(tld); + size_t numa_count = _mi_os_numa_node_count(); + if (numa_count<=1) return 0; // optimize on single numa node systems: always node 0 + // never more than the node count and >= 0 + size_t numa_node = _mi_prim_numa_node(); + if (numa_node >= numa_count) { numa_node = numa_node % numa_count; } + return (int)numa_node; +} |