jemalloc/src/hpa_central.c
2026-03-10 18:14:33 -07:00

121 lines
3.4 KiB
C

#include "jemalloc/internal/jemalloc_preamble.h"
#include "jemalloc/internal/jemalloc_internal_includes.h"
#include "jemalloc/internal/hpa_central.h"
#include "jemalloc/internal/tsd.h"
#include "jemalloc/internal/witness.h"
#define HPA_EDEN_SIZE (128 * HUGEPAGE)
bool
hpa_central_init(
hpa_central_t *central, base_t *base, const hpa_hooks_t *hooks) {
/* malloc_conf processing should have filtered out these cases. */
assert(hpa_supported());
bool err;
err = malloc_mutex_init(&central->grow_mtx, "hpa_central_grow",
WITNESS_RANK_HPA_CENTRAL_GROW, malloc_mutex_rank_exclusive);
if (err) {
return true;
}
central->base = base;
central->eden = NULL;
central->eden_len = 0;
central->hooks = *hooks;
return false;
}
static hpdata_t *
hpa_alloc_ps(tsdn_t *tsdn, hpa_central_t *central) {
return (hpdata_t *)base_alloc(
tsdn, central->base, sizeof(hpdata_t), CACHELINE);
}
hpdata_t *
hpa_central_extract(tsdn_t *tsdn, hpa_central_t *central, size_t size,
uint64_t age, bool hugify_eager, bool *oom) {
/* Don't yet support big allocations; these should get filtered out. */
assert(size <= HUGEPAGE);
/*
* Should only try to extract from the central allocator if the local
* shard is exhausted. We should hold the grow_mtx on that shard.
*/
witness_assert_positive_depth_to_rank(
tsdn_witness_tsdp_get(tsdn), WITNESS_RANK_HPA_SHARD_GROW);
malloc_mutex_lock(tsdn, &central->grow_mtx);
*oom = false;
hpdata_t *ps = NULL;
bool start_as_huge = hugify_eager
|| (init_system_thp_mode == system_thp_mode_always
&& opt_experimental_hpa_start_huge_if_thp_always);
/* Is eden a perfect fit? */
if (central->eden != NULL && central->eden_len == HUGEPAGE) {
ps = hpa_alloc_ps(tsdn, central);
if (ps == NULL) {
*oom = true;
malloc_mutex_unlock(tsdn, &central->grow_mtx);
return NULL;
}
hpdata_init(ps, central->eden, age, start_as_huge);
central->eden = NULL;
central->eden_len = 0;
malloc_mutex_unlock(tsdn, &central->grow_mtx);
return ps;
}
/*
* We're about to try to allocate from eden by splitting. If eden is
* NULL, we have to allocate it too. Otherwise, we just have to
* allocate an edata_t for the new psset.
*/
if (central->eden == NULL) {
/* Allocate address space, bailing if we fail. */
void *new_eden = central->hooks.map(HPA_EDEN_SIZE);
if (new_eden == NULL) {
*oom = true;
malloc_mutex_unlock(tsdn, &central->grow_mtx);
return NULL;
}
if (hugify_eager) {
central->hooks.hugify(
new_eden, HPA_EDEN_SIZE, /* sync */ false);
}
ps = hpa_alloc_ps(tsdn, central);
if (ps == NULL) {
central->hooks.unmap(new_eden, HPA_EDEN_SIZE);
*oom = true;
malloc_mutex_unlock(tsdn, &central->grow_mtx);
return NULL;
}
central->eden = new_eden;
central->eden_len = HPA_EDEN_SIZE;
} else {
/* Eden is already nonempty; only need an edata for ps. */
ps = hpa_alloc_ps(tsdn, central);
if (ps == NULL) {
*oom = true;
malloc_mutex_unlock(tsdn, &central->grow_mtx);
return NULL;
}
}
assert(ps != NULL);
assert(central->eden != NULL);
assert(central->eden_len > HUGEPAGE);
assert(central->eden_len % HUGEPAGE == 0);
assert(HUGEPAGE_ADDR2BASE(central->eden) == central->eden);
hpdata_init(ps, central->eden, age, start_as_huge);
char *eden_char = (char *)central->eden;
eden_char += HUGEPAGE;
central->eden = (void *)eden_char;
central->eden_len -= HUGEPAGE;
malloc_mutex_unlock(tsdn, &central->grow_mtx);
return ps;
}