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track commit status per block in a region

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daan 2019-11-11 15:45:31 -08:00
parent db3f1c4bfa
commit 5e6754f3f7
1 changed files with 32 additions and 17 deletions
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49
src/memory.c
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@ -59,7 +59,7 @@ static bool mi_delay_remove(mi_delay_slot_t* slots, size_t count, void* p, size_
// Constants
#if (MI_INTPTR_SIZE==8)
#define MI_HEAP_REGION_MAX_SIZE (256 * GiB) // 40KiB for the region map
#define MI_HEAP_REGION_MAX_SIZE (256 * GiB) // 48KiB for the region map
#elif (MI_INTPTR_SIZE==4)
#define MI_HEAP_REGION_MAX_SIZE (3 * GiB) // ~ KiB for the region map
#else
@ -94,8 +94,9 @@ static inline void* mi_region_info_read(mi_region_info_t info, bool* is_large, b
typedef struct mem_region_s {
volatile _Atomic(mi_region_info_t) info; // start of the memory area (and flags)
volatile _Atomic(uintptr_t) numa_node; // associated numa node + 1 (so 0 is no association)
mi_bitmap_field_t in_use;
mi_bitmap_field_t dirty;
mi_bitmap_field_t in_use; // bit per in-use block
mi_bitmap_field_t dirty; // track if non-zero per block
mi_bitmap_field_t commit; // track if committed per block (if `!info.is_committed))
size_t arena_memid; // if allocated from a (huge page) arena
} mem_region_t;
@ -165,20 +166,20 @@ static bool mi_memid_indices(size_t id, mem_region_t** region, mi_bitmap_index_t
Allocate a region is allocated from the OS (or an arena)
-----------------------------------------------------------------------------*/
static bool mi_region_try_alloc_os(size_t blocks, bool commit, bool allow_large, mem_region_t** region, mi_bitmap_index_t* bit_idx, mi_os_tld_t* tld)
static bool mi_region_try_alloc_os(size_t blocks, bool commit, bool allow_large, mem_region_t** region, mi_bitmap_index_t* bit_idx, mi_os_tld_t* tld)
{
// not out of regions yet?
if (mi_atomic_read_relaxed(&regions_count) >= MI_REGION_MAX - 1) return false;
// try to allocate a fresh region from the OS
bool region_commit = (commit && mi_option_is_enabled(mi_option_eager_region_commit));
bool region_large = (commit && allow_large);
bool is_zero = false;
bool region_large = (commit && allow_large);
bool is_zero = false;
size_t arena_memid = 0;
void* const start = _mi_arena_alloc_aligned(MI_REGION_SIZE, MI_SEGMENT_ALIGN, &region_commit, &region_large, &is_zero, &arena_memid, tld);
if (start == NULL) return false;
mi_assert_internal(!(region_large && !allow_large));
// claim a fresh slot
const uintptr_t idx = mi_atomic_increment(&regions_count);
if (idx >= MI_REGION_MAX) {
@ -191,8 +192,13 @@ static bool mi_region_try_alloc_os(size_t blocks, bool commit, bool allow_large,
mem_region_t* r = &regions[idx];
r->numa_node = _mi_os_numa_node(tld) + 1;
r->arena_memid = arena_memid;
mi_atomic_write(&r->in_use, 0);
mi_atomic_write(&r->dirty, (is_zero ? 0 : ~0UL));
mi_atomic_write(&r->commit, (region_commit ? ~0UL : 0));
*bit_idx = 0;
mi_bitmap_claim(&r->in_use, 1, blocks, *bit_idx, NULL);
// and share it
mi_atomic_write(&r->info, mi_region_info_create(start, region_large, region_commit)); // now make it available to others
*region = r;
return true;
@ -269,20 +275,28 @@ static void* mi_region_try_alloc(size_t blocks, bool* commit, bool* is_large, bo
mi_assert_internal(!(region_is_large && !*is_large));
mi_assert_internal(start != NULL);
bool any_zero = false;
*is_zero = mi_bitmap_claim(&region->dirty, 1, blocks, bit_idx, &any_zero);
if (!mi_option_is_enabled(mi_option_eager_commit)) any_zero = true; // if no eager commit, even dirty segments may be partially committed
*is_zero = mi_bitmap_claim(&region->dirty, 1, blocks, bit_idx, NULL);
*is_large = region_is_large;
*memid = mi_memid_create(region, bit_idx);
void* p = (uint8_t*)start + (mi_bitmap_index_bit_in_field(bit_idx) * MI_SEGMENT_SIZE);
if (*commit && !region_is_committed && any_zero) { // want to commit, but not yet fully committed?
// ensure commit
_mi_os_commit(p, blocks * MI_SEGMENT_SIZE, is_zero, tld->stats);
if (region_is_committed) {
// always committed
*commit = true;
}
else if (*commit) {
// ensure commit
bool any_zero;
mi_bitmap_claim(&region->commit, 1, blocks, bit_idx, &any_zero);
if (any_zero) {
bool commit_zero;
_mi_mem_commit(p, blocks * MI_SEGMENT_SIZE, &commit_zero, tld);
if (commit_zero) *is_zero = true;
}
}
else {
*commit = region_is_committed || !any_zero;
}
// no need to commit, but check if already fully committed
*commit = mi_bitmap_is_claimed(&region->commit, 1, blocks, bit_idx);
}
// and return the allocation
mi_assert_internal(p != NULL);
@ -374,7 +388,8 @@ void _mi_mem_free(void* p, size_t size, size_t id, mi_os_tld_t* tld) {
mi_option_is_enabled(mi_option_segment_reset) &&
mi_option_is_enabled(mi_option_eager_commit)) // cannot reset halfway committed segments, use `option_page_reset` instead
{
_mi_os_reset(p, size, tld->stats);
// note: don't use `_mi_mem_reset` as it is shared with other threads!
_mi_os_reset(p, size, tld->stats); // TODO: maintain reset bits to unreset
}
if (!is_committed) {
// adjust commit statistics as we commit again when re-using the same slot