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San: Bump alloc frequently reused guarded allocations

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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
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32
src/extent.c
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@ -87,6 +87,7 @@ ecache_alloc(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks, ecache_t *ecache,
edata_t *edata = extent_recycle(tsdn, pac, ehooks, ecache, expand_edata,
size, alignment, zero, &commit, false, guarded);
assert(edata == NULL || edata_pai_get(edata) == EXTENT_PAI_PAC);
assert(edata == NULL || edata_guarded_get(edata) == guarded);
return edata;
}
@ -179,7 +180,7 @@ ecache_evict(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks,
goto label_return;
}
eset_remove(eset, edata);
if (!ecache->delay_coalesce) {
if (!ecache->delay_coalesce || edata_guarded_get(edata)) {
break;
}
/* Try to coalesce. */
@ -399,11 +400,6 @@ extent_recycle_extract(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks,
}
}
} else {
/*
* If split and merge are not allowed (Windows w/o retain), try
* exact fit only.
*/
bool exact_only = (!maps_coalesce && !opt_retain) || guarded;
/*
* A large extent might be broken up from its original size to
* some small size to satisfy a small request. When that small
@ -415,7 +411,18 @@ extent_recycle_extract(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks,
*/
unsigned lg_max_fit = ecache->delay_coalesce
? (unsigned)opt_lg_extent_max_active_fit : SC_PTR_BITS;
edata = eset_fit(eset, size, alignment, exact_only, lg_max_fit);
/*
* If split and merge are not allowed (Windows w/o retain), try
* exact fit only.
*
* For simplicity purposes, splitting guarded extents is not
* supported. Hence, we do only exact fit for guarded
* allocations.
*/
bool exact_only = (!maps_coalesce && !opt_retain) || guarded;
edata = eset_fit(eset, size, alignment, exact_only,
lg_max_fit);
}
if (edata == NULL) {
return NULL;
@ -474,6 +481,7 @@ extent_split_interior(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks,
/* Split the lead. */
if (leadsize != 0) {
assert(!edata_guarded_get(*edata));
*lead = *edata;
*edata = extent_split_impl(tsdn, pac, ehooks, *lead, leadsize,
size + trailsize, /* holding_core_locks*/ true);
@ -486,6 +494,7 @@ extent_split_interior(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks,
/* Split the trail. */
if (trailsize != 0) {
assert(!edata_guarded_get(*edata));
*trail = extent_split_impl(tsdn, pac, ehooks, *edata, size,
trailsize, /* holding_core_locks */ true);
if (*trail == NULL) {
@ -510,6 +519,7 @@ static edata_t *
extent_recycle_split(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks,
ecache_t *ecache, edata_t *expand_edata, size_t size, size_t alignment,
edata_t *edata, bool growing_retained) {
assert(!edata_guarded_get(edata) || size == edata_size_get(edata));
malloc_mutex_assert_owner(tsdn, &ecache->mtx);
edata_t *lead;
@ -576,8 +586,10 @@ extent_recycle(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks, ecache_t *ecache,
witness_assert_depth_to_rank(tsdn_witness_tsdp_get(tsdn),
WITNESS_RANK_CORE, growing_retained ? 1 : 0);
assert(!guarded || expand_edata == NULL);
assert(!guarded || alignment <= PAGE);
malloc_mutex_lock(tsdn, &ecache->mtx);
edata_t *edata = extent_recycle_extract(tsdn, pac, ehooks, ecache,
expand_edata, size, alignment, guarded);
if (edata == NULL) {
@ -746,7 +758,6 @@ extent_grow_retained(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks,
size_t size = edata_size_get(edata);
ehooks_zero(tsdn, ehooks, addr, size);
}
return edata;
label_err:
malloc_mutex_unlock(tsdn, &pac->grow_mtx);
@ -801,6 +812,7 @@ extent_coalesce(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks, ecache_t *ecache,
static edata_t *
extent_try_coalesce_impl(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks,
ecache_t *ecache, edata_t *edata, bool *coalesced) {
assert(!edata_guarded_get(edata));
/*
* We avoid checking / locking inactive neighbors for large size
* classes, since they are eagerly coalesced on deallocation which can
@ -907,7 +919,7 @@ extent_record(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks, ecache_t *ecache,
goto label_skip_coalesce;
}
if (!ecache->delay_coalesce) {
edata = extent_try_coalesce(tsdn, pac, ehooks, ecache, edata,
edata = extent_try_coalesce(tsdn, pac, ehooks, ecache, edata,
NULL);
} else if (edata_size_get(edata) >= SC_LARGE_MINCLASS) {
assert(ecache == &pac->ecache_dirty);
@ -1014,7 +1026,7 @@ extent_dalloc_wrapper(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks,
/* Avoid calling the default extent_dalloc unless have to. */
if (!ehooks_dalloc_will_fail(ehooks)) {
/* Restore guard pages for dalloc / unmap. */
/* Remove guard pages for dalloc / unmap. */
if (edata_guarded_get(edata)) {
assert(ehooks_are_default(ehooks));
san_unguard_pages_two_sided(tsdn, ehooks, edata,