romenskiy2012/jemalloc
1
0
Fork 0
mirror of https://github.com/jemalloc/jemalloc.git synced 2026-05-05 11:27:18 +03:00
Code Issues Projects Releases Packages Wiki Activity

San: Bump alloc frequently reused guarded allocations

Browse source 
To utilize a separate retained area for guarded extents, use bump alloc
to allocate those extents.
This commit is contained in:
Alex Lapenkou 2021-10-28 12:08:10 -07:00 • committed by Alexander Lapenkov
parent f56f5b9930
commit 800ce49c19
10 changed files with 106 additions and 56 deletions
Download patch file Download diff file Expand all files Collapse all files

48
src/pac.c
View file

@ -81,6 +81,9 @@ pac_init(tsdn_t *tsdn, pac_t *pac, base_t *base, emap_t *emap,
if (decay_init(&pac->decay_muzzy, cur_time, muzzy_decay_ms)) {
return true;
}
if (san_bump_alloc_init(&pac->sba)) {
return true;
}
pac->base = base;
pac->emap = emap;
@ -132,18 +135,24 @@ pac_alloc_real(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks, size_t size,
static edata_t *
pac_alloc_new_guarded(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks, size_t size,
size_t alignment, bool zero) {
size_t alignment, bool zero, bool frequent_reuse) {
assert(alignment <= PAGE);
size_t size_with_guards = size + SAN_PAGE_GUARDS_SIZE;
/* Alloc a non-guarded extent first.*/
edata_t *edata = pac_alloc_real(tsdn, pac, ehooks, size_with_guards,
/* alignment */ PAGE, zero, /* guarded */ false);
if (edata != NULL) {
/* Add guards around it. */
assert(edata_size_get(edata) == size_with_guards);
san_guard_pages(tsdn, ehooks, edata, pac->emap, true, true,
true);
edata_t *edata;
if (san_bump_enabled() && frequent_reuse) {
edata = san_bump_alloc(tsdn, &pac->sba, pac, ehooks, size,
zero);
} else {
size_t size_with_guards = san_two_side_guarded_sz(size);
/* Alloc a non-guarded extent first.*/
edata = pac_alloc_real(tsdn, pac, ehooks, size_with_guards,
/* alignment */ PAGE, zero, /* guarded */ false);
if (edata != NULL) {
/* Add guards around it. */
assert(edata_size_get(edata) == size_with_guards);
san_guard_pages_two_sided(tsdn, ehooks, edata,
pac->emap, true);
}
}
assert(edata == NULL || (edata_guarded_get(edata) &&
edata_size_get(edata) == size));
@ -158,12 +167,21 @@ pac_alloc_impl(tsdn_t *tsdn, pai_t *self, size_t size, size_t alignment,
pac_t *pac = (pac_t *)self;
ehooks_t *ehooks = pac_ehooks_get(pac);
edata_t *edata = pac_alloc_real(tsdn, pac, ehooks, size, alignment,
zero, guarded);
edata_t *edata = NULL;
/*
* The condition is an optimization - not frequently reused guarded
* allocations are never put in the ecache. pac_alloc_real also
* doesn't grow retained for guarded allocations. So pac_alloc_real
* for such allocations would always return NULL.
* */
if (!guarded || frequent_reuse) {
edata = pac_alloc_real(tsdn, pac, ehooks, size, alignment,
zero, guarded);
}
if (edata == NULL && guarded) {
/* No cached guarded extents; creating a new one. */
edata = pac_alloc_new_guarded(tsdn, pac, ehooks, size,
alignment, zero);
alignment, zero, frequent_reuse);
}
return edata;
@ -189,8 +207,8 @@ pac_expand_impl(tsdn_t *tsdn, pai_t *self, edata_t *edata, size_t old_size,
}
if (trail == NULL) {
trail = ecache_alloc_grow(tsdn, pac, ehooks,
&pac->ecache_retained, edata, expand_amount, PAGE,
zero, /* guarded */ false);
&pac->ecache_retained, edata, expand_amount, PAGE, zero,
/* guarded */ false);
mapped_add = expand_amount;
}
if (trail == NULL) {