HPA: Implement batch allocation.

This commit is contained in:
David Goldblatt 2021-01-20 14:55:42 -08:00 committed by David Goldblatt
parent cdae6706a6
commit ce9386370a
2 changed files with 168 additions and 97 deletions

189
src/hpa.c
View File

@ -10,6 +10,8 @@
static edata_t *hpa_alloc(tsdn_t *tsdn, pai_t *self, size_t size,
size_t alignment, bool zero);
static size_t hpa_alloc_batch(tsdn_t *tsdn, pai_t *self, size_t size,
size_t nallocs, edata_list_active_t *results);
static bool hpa_expand(tsdn_t *tsdn, pai_t *self, edata_t *edata,
size_t old_size, size_t new_size, bool zero);
static bool hpa_shrink(tsdn_t *tsdn, pai_t *self, edata_t *edata,
@ -425,13 +427,11 @@ hpa_do_deferred_work(tsdn_t *tsdn, hpa_shard_t *shard) {
}
static edata_t *
hpa_try_alloc_no_grow(tsdn_t *tsdn, hpa_shard_t *shard, size_t size, bool *oom) {
hpa_try_alloc_one_no_grow(tsdn_t *tsdn, hpa_shard_t *shard, size_t size,
bool *oom) {
bool err;
malloc_mutex_lock(tsdn, &shard->mtx);
edata_t *edata = edata_cache_small_get(tsdn, &shard->ecs);
*oom = false;
if (edata == NULL) {
malloc_mutex_unlock(tsdn, &shard->mtx);
*oom = true;
return NULL;
}
@ -440,7 +440,6 @@ hpa_try_alloc_no_grow(tsdn_t *tsdn, hpa_shard_t *shard, size_t size, bool *oom)
hpdata_t *ps = psset_pick_alloc(&shard->psset, size);
if (ps == NULL) {
edata_cache_small_put(tsdn, &shard->ecs, edata);
malloc_mutex_unlock(tsdn, &shard->mtx);
return NULL;
}
@ -487,42 +486,61 @@ hpa_try_alloc_no_grow(tsdn_t *tsdn, hpa_shard_t *shard, size_t size, bool *oom)
*/
psset_update_end(&shard->psset, ps);
edata_cache_small_put(tsdn, &shard->ecs, edata);
malloc_mutex_unlock(tsdn, &shard->mtx);
*oom = true;
return NULL;
}
hpa_update_purge_hugify_eligibility(shard, ps);
psset_update_end(&shard->psset, ps);
hpa_do_deferred_work(tsdn, shard);
malloc_mutex_unlock(tsdn, &shard->mtx);
return edata;
}
static edata_t *
hpa_alloc_psset(tsdn_t *tsdn, hpa_shard_t *shard, size_t size) {
assert(size <= shard->opts.slab_max_alloc);
bool err;
bool oom;
edata_t *edata;
edata = hpa_try_alloc_no_grow(tsdn, shard, size, &oom);
if (edata != NULL) {
return edata;
static size_t
hpa_try_alloc_batch_no_grow(tsdn_t *tsdn, hpa_shard_t *shard, size_t size,
bool *oom, size_t nallocs, edata_list_active_t *results) {
malloc_mutex_lock(tsdn, &shard->mtx);
size_t nsuccess = 0;
for (; nsuccess < nallocs; nsuccess++) {
edata_t *edata = hpa_try_alloc_one_no_grow(tsdn, shard, size,
oom);
if (edata == NULL) {
break;
}
edata_list_active_append(results, edata);
}
/* Nothing in the psset works; we have to grow it. */
hpa_do_deferred_work(tsdn, shard);
malloc_mutex_unlock(tsdn, &shard->mtx);
return nsuccess;
}
static size_t
hpa_alloc_batch_psset(tsdn_t *tsdn, hpa_shard_t *shard, size_t size,
size_t nallocs, edata_list_active_t *results) {
assert(size <= shard->opts.slab_max_alloc);
bool oom = false;
size_t nsuccess = hpa_try_alloc_batch_no_grow(tsdn, shard, size, &oom,
nallocs, results);
if (nsuccess == nallocs || oom) {
return nsuccess;
}
/*
* We didn't OOM, but weren't able to fill everything requested of us;
* try to grow.
*/
malloc_mutex_lock(tsdn, &shard->grow_mtx);
/*
* Check for grow races; maybe some earlier thread expanded the psset
* in between when we dropped the main mutex and grabbed the grow mutex.
*/
edata = hpa_try_alloc_no_grow(tsdn, shard, size, &oom);
if (edata != NULL || oom) {
nsuccess += hpa_try_alloc_batch_no_grow(tsdn, shard, size, &oom,
nallocs - nsuccess, results);
if (nsuccess == nallocs || oom) {
malloc_mutex_unlock(tsdn, &shard->grow_mtx);
return edata;
return nsuccess;
}
/*
@ -533,78 +551,28 @@ hpa_alloc_psset(tsdn_t *tsdn, hpa_shard_t *shard, size_t size) {
hpdata_t *ps = hpa_grow(tsdn, shard);
if (ps == NULL) {
malloc_mutex_unlock(tsdn, &shard->grow_mtx);
return NULL;
}
/* We got the pageslab; allocate from it. */
malloc_mutex_lock(tsdn, &shard->mtx);
psset_insert(&shard->psset, ps);
edata = edata_cache_small_get(tsdn, &shard->ecs);
if (edata == NULL) {
malloc_mutex_unlock(tsdn, &shard->mtx);
malloc_mutex_unlock(tsdn, &shard->grow_mtx);
return NULL;
return nsuccess;
}
/*
* TODO: the tail of this function is quite similar to the tail of
* hpa_try_alloc_no_grow (both, broadly, do the metadata management of
* initializing an edata_t from an hpdata_t once both have been
* allocated). The only differences are in error case handling and lock
* management (we hold grow_mtx, but should drop it before doing any
* deferred work). With a little refactoring, we could unify the paths.
* We got the pageslab; allocate from it. This does an unlock followed
* by a lock on the same mutex, and holds the grow mutex while doing
* deferred work, but this is an uncommon path; the simplicity is worth
* it.
*/
psset_update_begin(&shard->psset, ps);
void *addr = hpdata_reserve_alloc(ps, size);
edata_init(edata, shard->ind, addr, size, /* slab */ false,
SC_NSIZES, /* sn */ 0, extent_state_active, /* zeroed */ false,
/* committed */ true, EXTENT_PAI_HPA, EXTENT_NOT_HEAD);
edata_ps_set(edata, ps);
err = emap_register_boundary(tsdn, shard->emap, edata,
SC_NSIZES, /* slab */ false);
if (err) {
hpdata_unreserve(ps, edata_addr_get(edata),
edata_size_get(edata));
edata_cache_small_put(tsdn, &shard->ecs, edata);
/* We'll do a fake purge; the pages weren't really touched. */
hpdata_purge_state_t purge_state;
void *purge_addr;
size_t purge_size;
hpdata_purge_begin(ps, &purge_state);
bool found_extent = hpdata_purge_next(ps, &purge_state,
&purge_addr, &purge_size);
assert(found_extent);
assert(purge_addr == addr);
assert(purge_size == size);
found_extent = hpdata_purge_next(ps, &purge_state,
&purge_addr, &purge_size);
assert(!found_extent);
hpdata_purge_end(ps, &purge_state);
psset_update_end(&shard->psset, ps);
malloc_mutex_lock(tsdn, &shard->mtx);
psset_insert(&shard->psset, ps);
malloc_mutex_unlock(tsdn, &shard->mtx);
malloc_mutex_unlock(tsdn, &shard->grow_mtx);
return NULL;
}
hpa_update_purge_hugify_eligibility(shard, ps);
psset_update_end(&shard->psset, ps);
nsuccess += hpa_try_alloc_batch_no_grow(tsdn, shard, size, &oom,
nallocs - nsuccess, results);
/*
* Drop grow_mtx before doing deferred work; other threads blocked on it
* should be allowed to proceed while we're working.
*/
malloc_mutex_unlock(tsdn, &shard->grow_mtx);
hpa_do_deferred_work(tsdn, shard);
malloc_mutex_unlock(tsdn, &shard->mtx);
return edata;
return nsuccess;
}
static hpa_shard_t *
@ -616,28 +584,27 @@ hpa_from_pai(pai_t *self) {
return (hpa_shard_t *)self;
}
static edata_t *
hpa_alloc(tsdn_t *tsdn, pai_t *self, size_t size,
size_t alignment, bool zero) {
static size_t
hpa_alloc_batch(tsdn_t *tsdn, pai_t *self, size_t size, size_t nallocs,
edata_list_active_t *results) {
assert(nallocs > 0);
assert((size & PAGE_MASK) == 0);
witness_assert_depth_to_rank(tsdn_witness_tsdp_get(tsdn),
WITNESS_RANK_CORE, 0);
hpa_shard_t *shard = hpa_from_pai(self);
/* We don't handle alignment or zeroing for now. */
if (alignment > PAGE || zero) {
return NULL;
}
if (size > shard->opts.slab_max_alloc) {
return NULL;
return 0;
}
edata_t *edata = hpa_alloc_psset(tsdn, shard, size);
size_t nsuccess = hpa_alloc_batch_psset(tsdn, shard, size, nallocs,
results);
witness_assert_depth_to_rank(tsdn_witness_tsdp_get(tsdn),
WITNESS_RANK_CORE, 0);
if (edata != NULL) {
edata_t *edata;
ql_foreach(edata, &results->head, ql_link_active) {
emap_assert_mapped(tsdn, shard->emap, edata);
assert(edata_pai_get(edata) == EXTENT_PAI_HPA);
assert(edata_state_get(edata) == extent_state_active);
@ -648,6 +615,29 @@ hpa_alloc(tsdn_t *tsdn, pai_t *self, size_t size,
assert(edata_base_get(edata) == edata_addr_get(edata));
assert(edata_base_get(edata) != NULL);
}
return nsuccess;
}
static edata_t *
hpa_alloc(tsdn_t *tsdn, pai_t *self, size_t size, size_t alignment, bool zero) {
assert((size & PAGE_MASK) == 0);
witness_assert_depth_to_rank(tsdn_witness_tsdp_get(tsdn),
WITNESS_RANK_CORE, 0);
/* We don't handle alignment or zeroing for now. */
if (alignment > PAGE || zero) {
return NULL;
}
/*
* An alloc with alignment == PAGE and zero == false is equivalent to a
* batch alloc of 1. Just do that, so we can share code.
*/
edata_list_active_t results;
edata_list_active_init(&results);
size_t nallocs = hpa_alloc_batch(tsdn, self, size, /* nallocs */ 1,
&results);
assert(nallocs == 0 || nallocs == 1);
edata_t *edata = edata_list_active_first(&results);
return edata;
}
@ -677,6 +667,15 @@ hpa_dalloc_prepare_unlocked(tsdn_t *tsdn, hpa_shard_t *shard, edata_t *edata) {
assert(edata_committed_get(edata));
assert(edata_base_get(edata) != NULL);
/*
* Another thread shouldn't be trying to touch the metadata of an
* allocation being freed. The one exception is a merge attempt from a
* lower-addressed PAC extent; in this case we have a nominal race on
* the edata metadata bits, but in practice the fact that the PAI bits
* are different will prevent any further access. The race is bad, but
* benign in practice, and the long term plan is to track enough state
* in the rtree to prevent these merge attempts in the first place.
*/
edata_addr_set(edata, edata_base_get(edata));
edata_zeroed_set(edata, false);
emap_deregister_boundary(tsdn, shard->emap, edata);

View File

@ -211,6 +211,77 @@ TEST_BEGIN(test_stress) {
}
TEST_END
static void
expect_contiguous(edata_t **edatas, size_t nedatas) {
for (size_t i = 0; i < nedatas; i++) {
size_t expected = (size_t)edata_base_get(edatas[0])
+ i * PAGE;
expect_zu_eq(expected, (size_t)edata_base_get(edatas[i]),
"Mismatch at index %zu", i);
}
}
TEST_BEGIN(test_alloc_dalloc_batch) {
test_skip_if(!hpa_supported());
hpa_shard_t *shard = create_test_data();
tsdn_t *tsdn = tsd_tsdn(tsd_fetch());
enum {NALLOCS = 8};
edata_t *allocs[NALLOCS];
/*
* Allocate a mix of ways; first half from regular alloc, second half
* from alloc_batch.
*/
for (size_t i = 0; i < NALLOCS / 2; i++) {
allocs[i] = pai_alloc(tsdn, &shard->pai, PAGE, PAGE,
/* zero */ false);
expect_ptr_not_null(allocs[i], "Unexpected alloc failure");
}
edata_list_active_t allocs_list;
edata_list_active_init(&allocs_list);
size_t nsuccess = pai_alloc_batch(tsdn, &shard->pai, PAGE, NALLOCS / 2,
&allocs_list);
expect_zu_eq(NALLOCS / 2, nsuccess, "Unexpected oom");
for (size_t i = NALLOCS / 2; i < NALLOCS; i++) {
allocs[i] = edata_list_active_first(&allocs_list);
edata_list_active_remove(&allocs_list, allocs[i]);
}
/*
* Should have allocated them contiguously, despite the differing
* methods used.
*/
void *orig_base = edata_base_get(allocs[0]);
expect_contiguous(allocs, NALLOCS);
/*
* Batch dalloc the first half, individually deallocate the second half.
*/
for (size_t i = 0; i < NALLOCS / 2; i++) {
edata_list_active_append(&allocs_list, allocs[i]);
}
pai_dalloc_batch(tsdn, &shard->pai, &allocs_list);
for (size_t i = NALLOCS / 2; i < NALLOCS; i++) {
pai_dalloc(tsdn, &shard->pai, allocs[i]);
}
/* Reallocate (individually), and ensure reuse and contiguity. */
for (size_t i = 0; i < NALLOCS; i++) {
allocs[i] = pai_alloc(tsdn, &shard->pai, PAGE, PAGE,
/* zero */ false);
expect_ptr_not_null(allocs[i], "Unexpected alloc failure.");
}
void *new_base = edata_base_get(allocs[0]);
expect_ptr_eq(orig_base, new_base,
"Failed to reuse the allocated memory.");
expect_contiguous(allocs, NALLOCS);
destroy_test_data(shard);
}
TEST_END
int
main(void) {
/*
@ -227,5 +298,6 @@ main(void) {
(void)mem_tree_destroy;
return test_no_reentrancy(
test_alloc_max,
test_stress);
test_stress,
test_alloc_dalloc_batch);
}