Added TCMalloc and JEMalloc projects

BeefRT/JEMalloc/src/pac.c

@@ -0,0 +1,587 @@
+#include "jemalloc/internal/jemalloc_preamble.h"
+#include "jemalloc/internal/jemalloc_internal_includes.h"
+
+#include "jemalloc/internal/pac.h"
+#include "jemalloc/internal/san.h"
+
+static edata_t *pac_alloc_impl(tsdn_t *tsdn, pai_t *self, size_t size,
+    size_t alignment, bool zero, bool guarded, bool frequent_reuse,
+    bool *deferred_work_generated);
+static bool pac_expand_impl(tsdn_t *tsdn, pai_t *self, edata_t *edata,
+    size_t old_size, size_t new_size, bool zero, bool *deferred_work_generated);
+static bool pac_shrink_impl(tsdn_t *tsdn, pai_t *self, edata_t *edata,
+    size_t old_size, size_t new_size, bool *deferred_work_generated);
+static void pac_dalloc_impl(tsdn_t *tsdn, pai_t *self, edata_t *edata,
+    bool *deferred_work_generated);
+static uint64_t pac_time_until_deferred_work(tsdn_t *tsdn, pai_t *self);
+
+static inline void
+pac_decay_data_get(pac_t *pac, extent_state_t state,
+    decay_t **r_decay, pac_decay_stats_t **r_decay_stats, ecache_t **r_ecache) {
+	switch(state) {
+	case extent_state_dirty:
+		*r_decay = &pac->decay_dirty;
+		*r_decay_stats = &pac->stats->decay_dirty;
+		*r_ecache = &pac->ecache_dirty;
+		return;
+	case extent_state_muzzy:
+		*r_decay = &pac->decay_muzzy;
+		*r_decay_stats = &pac->stats->decay_muzzy;
+		*r_ecache = &pac->ecache_muzzy;
+		return;
+	default:
+		unreachable();
+	}
+}
+
+bool
+pac_init(tsdn_t *tsdn, pac_t *pac, base_t *base, emap_t *emap,
+    edata_cache_t *edata_cache, nstime_t *cur_time,
+    size_t pac_oversize_threshold, ssize_t dirty_decay_ms,
+    ssize_t muzzy_decay_ms, pac_stats_t *pac_stats, malloc_mutex_t *stats_mtx) {
+	unsigned ind = base_ind_get(base);
+	/*
+	 * Delay coalescing for dirty extents despite the disruptive effect on
+	 * memory layout for best-fit extent allocation, since cached extents
+	 * are likely to be reused soon after deallocation, and the cost of
+	 * merging/splitting extents is non-trivial.
+	 */
+	if (ecache_init(tsdn, &pac->ecache_dirty, extent_state_dirty, ind,
+	    /* delay_coalesce */ true)) {
+		return true;
+	}
+	/*
+	 * Coalesce muzzy extents immediately, because operations on them are in
+	 * the critical path much less often than for dirty extents.
+	 */
+	if (ecache_init(tsdn, &pac->ecache_muzzy, extent_state_muzzy, ind,
+	    /* delay_coalesce */ false)) {
+		return true;
+	}
+	/*
+	 * Coalesce retained extents immediately, in part because they will
+	 * never be evicted (and therefore there's no opportunity for delayed
+	 * coalescing), but also because operations on retained extents are not
+	 * in the critical path.
+	 */
+	if (ecache_init(tsdn, &pac->ecache_retained, extent_state_retained,
+	    ind, /* delay_coalesce */ false)) {
+		return true;
+	}
+	exp_grow_init(&pac->exp_grow);
+	if (malloc_mutex_init(&pac->grow_mtx, "extent_grow",
+	    WITNESS_RANK_EXTENT_GROW, malloc_mutex_rank_exclusive)) {
+		return true;
+	}
+	atomic_store_zu(&pac->oversize_threshold, pac_oversize_threshold,
+	    ATOMIC_RELAXED);
+	if (decay_init(&pac->decay_dirty, cur_time, dirty_decay_ms)) {
+		return true;
+	}
+	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;
+	pac->edata_cache = edata_cache;
+	pac->stats = pac_stats;
+	pac->stats_mtx = stats_mtx;
+	atomic_store_zu(&pac->extent_sn_next, 0, ATOMIC_RELAXED);
+
+	pac->pai.alloc = &pac_alloc_impl;
+	pac->pai.alloc_batch = &pai_alloc_batch_default;
+	pac->pai.expand = &pac_expand_impl;
+	pac->pai.shrink = &pac_shrink_impl;
+	pac->pai.dalloc = &pac_dalloc_impl;
+	pac->pai.dalloc_batch = &pai_dalloc_batch_default;
+	pac->pai.time_until_deferred_work = &pac_time_until_deferred_work;
+
+	return false;
+}
+
+static inline bool
+pac_may_have_muzzy(pac_t *pac) {
+	return pac_decay_ms_get(pac, extent_state_muzzy) != 0;
+}
+
+static edata_t *
+pac_alloc_real(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks, size_t size,
+    size_t alignment, bool zero, bool guarded) {
+	assert(!guarded || alignment <= PAGE);
+
+	edata_t *edata = ecache_alloc(tsdn, pac, ehooks, &pac->ecache_dirty,
+	    NULL, size, alignment, zero, guarded);
+
+	if (edata == NULL && pac_may_have_muzzy(pac)) {
+		edata = ecache_alloc(tsdn, pac, ehooks, &pac->ecache_muzzy,
+		    NULL, size, alignment, zero, guarded);
+	}
+	if (edata == NULL) {
+		edata = ecache_alloc_grow(tsdn, pac, ehooks,
+		    &pac->ecache_retained, NULL, size, alignment, zero,
+		    guarded);
+		if (config_stats && edata != NULL) {
+			atomic_fetch_add_zu(&pac->stats->pac_mapped, size,
+			    ATOMIC_RELAXED);
+		}
+	}
+
+	return edata;
+}
+
+static edata_t *
+pac_alloc_new_guarded(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks, size_t size,
+    size_t alignment, bool zero, bool frequent_reuse) {
+	assert(alignment <= PAGE);
+
+	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));
+
+	return edata;
+}
+
+static edata_t *
+pac_alloc_impl(tsdn_t *tsdn, pai_t *self, size_t size, size_t alignment,
+    bool zero, bool guarded, bool frequent_reuse,
+    bool *deferred_work_generated) {
+	pac_t *pac = (pac_t *)self;
+	ehooks_t *ehooks = pac_ehooks_get(pac);
+
+	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, frequent_reuse);
+	}
+
+	return edata;
+}
+
+static bool
+pac_expand_impl(tsdn_t *tsdn, pai_t *self, edata_t *edata, size_t old_size,
+    size_t new_size, bool zero, bool *deferred_work_generated) {
+	pac_t *pac = (pac_t *)self;
+	ehooks_t *ehooks = pac_ehooks_get(pac);
+
+	size_t mapped_add = 0;
+	size_t expand_amount = new_size - old_size;
+
+	if (ehooks_merge_will_fail(ehooks)) {
+		return true;
+	}
+	edata_t *trail = ecache_alloc(tsdn, pac, ehooks, &pac->ecache_dirty,
+	    edata, expand_amount, PAGE, zero, /* guarded*/ false);
+	if (trail == NULL) {
+		trail = ecache_alloc(tsdn, pac, ehooks, &pac->ecache_muzzy,
+		    edata, expand_amount, PAGE, zero, /* guarded*/ false);
+	}
+	if (trail == NULL) {
+		trail = ecache_alloc_grow(tsdn, pac, ehooks,
+		    &pac->ecache_retained, edata, expand_amount, PAGE, zero,
+		    /* guarded */ false);
+		mapped_add = expand_amount;
+	}
+	if (trail == NULL) {
+		return true;
+	}
+	if (extent_merge_wrapper(tsdn, pac, ehooks, edata, trail)) {
+		extent_dalloc_wrapper(tsdn, pac, ehooks, trail);
+		return true;
+	}
+	if (config_stats && mapped_add > 0) {
+		atomic_fetch_add_zu(&pac->stats->pac_mapped, mapped_add,
+		    ATOMIC_RELAXED);
+	}
+	return false;
+}
+
+static bool
+pac_shrink_impl(tsdn_t *tsdn, pai_t *self, edata_t *edata, size_t old_size,
+    size_t new_size, bool *deferred_work_generated) {
+	pac_t *pac = (pac_t *)self;
+	ehooks_t *ehooks = pac_ehooks_get(pac);
+
+	size_t shrink_amount = old_size - new_size;
+
+	if (ehooks_split_will_fail(ehooks)) {
+		return true;
+	}
+
+	edata_t *trail = extent_split_wrapper(tsdn, pac, ehooks, edata,
+	    new_size, shrink_amount, /* holding_core_locks */ false);
+	if (trail == NULL) {
+		return true;
+	}
+	ecache_dalloc(tsdn, pac, ehooks, &pac->ecache_dirty, trail);
+	*deferred_work_generated = true;
+	return false;
+}
+
+static void
+pac_dalloc_impl(tsdn_t *tsdn, pai_t *self, edata_t *edata,
+    bool *deferred_work_generated) {
+	pac_t *pac = (pac_t *)self;
+	ehooks_t *ehooks = pac_ehooks_get(pac);
+
+	if (edata_guarded_get(edata)) {
+		/*
+		 * Because cached guarded extents do exact fit only, large
+		 * guarded extents are restored on dalloc eagerly (otherwise
+		 * they will not be reused efficiently).  Slab sizes have a
+		 * limited number of size classes, and tend to cycle faster.
+		 *
+		 * In the case where coalesce is restrained (VirtualFree on
+		 * Windows), guarded extents are also not cached -- otherwise
+		 * during arena destroy / reset, the retained extents would not
+		 * be whole regions (i.e. they are split between regular and
+		 * guarded).
+		 */
+		if (!edata_slab_get(edata) || !maps_coalesce) {
+			assert(edata_size_get(edata) >= SC_LARGE_MINCLASS ||
+			    !maps_coalesce);
+			san_unguard_pages_two_sided(tsdn, ehooks, edata,
+			    pac->emap);
+		}
+	}
+
+	ecache_dalloc(tsdn, pac, ehooks, &pac->ecache_dirty, edata);
+	/* Purging of deallocated pages is deferred */
+	*deferred_work_generated = true;
+}
+
+static inline uint64_t
+pac_ns_until_purge(tsdn_t *tsdn, decay_t *decay, size_t npages) {
+	if (malloc_mutex_trylock(tsdn, &decay->mtx)) {
+		/* Use minimal interval if decay is contended. */
+		return BACKGROUND_THREAD_DEFERRED_MIN;
+	}
+	uint64_t result = decay_ns_until_purge(decay, npages,
+	    ARENA_DEFERRED_PURGE_NPAGES_THRESHOLD);
+
+	malloc_mutex_unlock(tsdn, &decay->mtx);
+	return result;
+}
+
+static uint64_t
+pac_time_until_deferred_work(tsdn_t *tsdn, pai_t *self) {
+	uint64_t time;
+	pac_t *pac = (pac_t *)self;
+
+	time = pac_ns_until_purge(tsdn,
+	    &pac->decay_dirty,
+	    ecache_npages_get(&pac->ecache_dirty));
+	if (time == BACKGROUND_THREAD_DEFERRED_MIN) {
+		return time;
+	}
+
+	uint64_t muzzy = pac_ns_until_purge(tsdn,
+	    &pac->decay_muzzy,
+	    ecache_npages_get(&pac->ecache_muzzy));
+	if (muzzy < time) {
+		time = muzzy;
+	}
+	return time;
+}
+
+bool
+pac_retain_grow_limit_get_set(tsdn_t *tsdn, pac_t *pac, size_t *old_limit,
+    size_t *new_limit) {
+	pszind_t new_ind JEMALLOC_CC_SILENCE_INIT(0);
+	if (new_limit != NULL) {
+		size_t limit = *new_limit;
+		/* Grow no more than the new limit. */
+		if ((new_ind = sz_psz2ind(limit + 1) - 1) >= SC_NPSIZES) {
+			return true;
+		}
+	}
+
+	malloc_mutex_lock(tsdn, &pac->grow_mtx);
+	if (old_limit != NULL) {
+		*old_limit = sz_pind2sz(pac->exp_grow.limit);
+	}
+	if (new_limit != NULL) {
+		pac->exp_grow.limit = new_ind;
+	}
+	malloc_mutex_unlock(tsdn, &pac->grow_mtx);
+
+	return false;
+}
+
+static size_t
+pac_stash_decayed(tsdn_t *tsdn, pac_t *pac, ecache_t *ecache,
+    size_t npages_limit, size_t npages_decay_max,
+    edata_list_inactive_t *result) {
+	witness_assert_depth_to_rank(tsdn_witness_tsdp_get(tsdn),
+	    WITNESS_RANK_CORE, 0);
+	ehooks_t *ehooks = pac_ehooks_get(pac);
+
+	/* Stash extents according to npages_limit. */
+	size_t nstashed = 0;
+	while (nstashed < npages_decay_max) {
+		edata_t *edata = ecache_evict(tsdn, pac, ehooks, ecache,
+		    npages_limit);
+		if (edata == NULL) {
+			break;
+		}
+		edata_list_inactive_append(result, edata);
+		nstashed += edata_size_get(edata) >> LG_PAGE;
+	}
+	return nstashed;
+}
+
+static size_t
+pac_decay_stashed(tsdn_t *tsdn, pac_t *pac, decay_t *decay,
+    pac_decay_stats_t *decay_stats, ecache_t *ecache, bool fully_decay,
+    edata_list_inactive_t *decay_extents) {
+	bool err;
+
+	size_t nmadvise = 0;
+	size_t nunmapped = 0;
+	size_t npurged = 0;
+
+	ehooks_t *ehooks = pac_ehooks_get(pac);
+
+	bool try_muzzy = !fully_decay
+	    && pac_decay_ms_get(pac, extent_state_muzzy) != 0;
+
+	for (edata_t *edata = edata_list_inactive_first(decay_extents); edata !=
+	    NULL; edata = edata_list_inactive_first(decay_extents)) {
+		edata_list_inactive_remove(decay_extents, edata);
+
+		size_t size = edata_size_get(edata);
+		size_t npages = size >> LG_PAGE;
+
+		nmadvise++;
+		npurged += npages;
+
+		switch (ecache->state) {
+		case extent_state_active:
+			not_reached();
+		case extent_state_dirty:
+			if (try_muzzy) {
+				err = extent_purge_lazy_wrapper(tsdn, ehooks,
+				    edata, /* offset */ 0, size);
+				if (!err) {
+					ecache_dalloc(tsdn, pac, ehooks,
+					    &pac->ecache_muzzy, edata);
+					break;
+				}
+			}
+			JEMALLOC_FALLTHROUGH;
+		case extent_state_muzzy:
+			extent_dalloc_wrapper(tsdn, pac, ehooks, edata);
+			nunmapped += npages;
+			break;
+		case extent_state_retained:
+		default:
+			not_reached();
+		}
+	}
+
+	if (config_stats) {
+		LOCKEDINT_MTX_LOCK(tsdn, *pac->stats_mtx);
+		locked_inc_u64(tsdn, LOCKEDINT_MTX(*pac->stats_mtx),
+		    &decay_stats->npurge, 1);
+		locked_inc_u64(tsdn, LOCKEDINT_MTX(*pac->stats_mtx),
+		    &decay_stats->nmadvise, nmadvise);
+		locked_inc_u64(tsdn, LOCKEDINT_MTX(*pac->stats_mtx),
+		    &decay_stats->purged, npurged);
+		LOCKEDINT_MTX_UNLOCK(tsdn, *pac->stats_mtx);
+		atomic_fetch_sub_zu(&pac->stats->pac_mapped,
+		    nunmapped << LG_PAGE, ATOMIC_RELAXED);
+	}
+
+	return npurged;
+}
+
+/*
+ * npages_limit: Decay at most npages_decay_max pages without violating the
+ * invariant: (ecache_npages_get(ecache) >= npages_limit).  We need an upper
+ * bound on number of pages in order to prevent unbounded growth (namely in
+ * stashed), otherwise unbounded new pages could be added to extents during the
+ * current decay run, so that the purging thread never finishes.
+ */
+static void
+pac_decay_to_limit(tsdn_t *tsdn, pac_t *pac, decay_t *decay,
+    pac_decay_stats_t *decay_stats, ecache_t *ecache, bool fully_decay,
+    size_t npages_limit, size_t npages_decay_max) {
+	witness_assert_depth_to_rank(tsdn_witness_tsdp_get(tsdn),
+	    WITNESS_RANK_CORE, 1);
+
+	if (decay->purging || npages_decay_max == 0) {
+		return;
+	}
+	decay->purging = true;
+	malloc_mutex_unlock(tsdn, &decay->mtx);
+
+	edata_list_inactive_t decay_extents;
+	edata_list_inactive_init(&decay_extents);
+	size_t npurge = pac_stash_decayed(tsdn, pac, ecache, npages_limit,
+	    npages_decay_max, &decay_extents);
+	if (npurge != 0) {
+		size_t npurged = pac_decay_stashed(tsdn, pac, decay,
+		    decay_stats, ecache, fully_decay, &decay_extents);
+		assert(npurged == npurge);
+	}
+
+	malloc_mutex_lock(tsdn, &decay->mtx);
+	decay->purging = false;
+}
+
+void
+pac_decay_all(tsdn_t *tsdn, pac_t *pac, decay_t *decay,
+    pac_decay_stats_t *decay_stats, ecache_t *ecache, bool fully_decay) {
+	malloc_mutex_assert_owner(tsdn, &decay->mtx);
+	pac_decay_to_limit(tsdn, pac, decay, decay_stats, ecache, fully_decay,
+	    /* npages_limit */ 0, ecache_npages_get(ecache));
+}
+
+static void
+pac_decay_try_purge(tsdn_t *tsdn, pac_t *pac, decay_t *decay,
+    pac_decay_stats_t *decay_stats, ecache_t *ecache,
+    size_t current_npages, size_t npages_limit) {
+	if (current_npages > npages_limit) {
+		pac_decay_to_limit(tsdn, pac, decay, decay_stats, ecache,
+		    /* fully_decay */ false, npages_limit,
+		    current_npages - npages_limit);
+	}
+}
+
+bool
+pac_maybe_decay_purge(tsdn_t *tsdn, pac_t *pac, decay_t *decay,
+    pac_decay_stats_t *decay_stats, ecache_t *ecache,
+    pac_purge_eagerness_t eagerness) {
+	malloc_mutex_assert_owner(tsdn, &decay->mtx);
+
+	/* Purge all or nothing if the option is disabled. */
+	ssize_t decay_ms = decay_ms_read(decay);
+	if (decay_ms <= 0) {
+		if (decay_ms == 0) {
+			pac_decay_to_limit(tsdn, pac, decay, decay_stats,
+			    ecache, /* fully_decay */ false,
+			    /* npages_limit */ 0, ecache_npages_get(ecache));
+		}
+		return false;
+	}
+
+	/*
+	 * If the deadline has been reached, advance to the current epoch and
+	 * purge to the new limit if necessary.  Note that dirty pages created
+	 * during the current epoch are not subject to purge until a future
+	 * epoch, so as a result purging only happens during epoch advances, or
+	 * being triggered by background threads (scheduled event).
+	 */
+	nstime_t time;
+	nstime_init_update(&time);
+	size_t npages_current = ecache_npages_get(ecache);
+	bool epoch_advanced = decay_maybe_advance_epoch(decay, &time,
+	    npages_current);
+	if (eagerness == PAC_PURGE_ALWAYS
+	    || (epoch_advanced && eagerness == PAC_PURGE_ON_EPOCH_ADVANCE)) {
+		size_t npages_limit = decay_npages_limit_get(decay);
+		pac_decay_try_purge(tsdn, pac, decay, decay_stats, ecache,
+		    npages_current, npages_limit);
+	}
+
+	return epoch_advanced;
+}
+
+bool
+pac_decay_ms_set(tsdn_t *tsdn, pac_t *pac, extent_state_t state,
+    ssize_t decay_ms, pac_purge_eagerness_t eagerness) {
+	decay_t *decay;
+	pac_decay_stats_t *decay_stats;
+	ecache_t *ecache;
+	pac_decay_data_get(pac, state, &decay, &decay_stats, &ecache);
+
+	if (!decay_ms_valid(decay_ms)) {
+		return true;
+	}
+
+	malloc_mutex_lock(tsdn, &decay->mtx);
+	/*
+	 * Restart decay backlog from scratch, which may cause many dirty pages
+	 * to be immediately purged.  It would conceptually be possible to map
+	 * the old backlog onto the new backlog, but there is no justification
+	 * for such complexity since decay_ms changes are intended to be
+	 * infrequent, either between the {-1, 0, >0} states, or a one-time
+	 * arbitrary change during initial arena configuration.
+	 */
+	nstime_t cur_time;
+	nstime_init_update(&cur_time);
+	decay_reinit(decay, &cur_time, decay_ms);
+	pac_maybe_decay_purge(tsdn, pac, decay, decay_stats, ecache, eagerness);
+	malloc_mutex_unlock(tsdn, &decay->mtx);
+
+	return false;
+}
+
+ssize_t
+pac_decay_ms_get(pac_t *pac, extent_state_t state) {
+	decay_t *decay;
+	pac_decay_stats_t *decay_stats;
+	ecache_t *ecache;
+	pac_decay_data_get(pac, state, &decay, &decay_stats, &ecache);
+	return decay_ms_read(decay);
+}
+
+void
+pac_reset(tsdn_t *tsdn, pac_t *pac) {
+	/*
+	 * No-op for now; purging is still done at the arena-level.  It should
+	 * get moved in here, though.
+	 */
+	(void)tsdn;
+	(void)pac;
+}
+
+void
+pac_destroy(tsdn_t *tsdn, pac_t *pac) {
+	assert(ecache_npages_get(&pac->ecache_dirty) == 0);
+	assert(ecache_npages_get(&pac->ecache_muzzy) == 0);
+	/*
+	 * Iterate over the retained extents and destroy them.  This gives the
+	 * extent allocator underlying the extent hooks an opportunity to unmap
+	 * all retained memory without having to keep its own metadata
+	 * structures.  In practice, virtual memory for dss-allocated extents is
+	 * leaked here, so best practice is to avoid dss for arenas to be
+	 * destroyed, or provide custom extent hooks that track retained
+	 * dss-based extents for later reuse.
+	 */
+	ehooks_t *ehooks = pac_ehooks_get(pac);
+	edata_t *edata;
+	while ((edata = ecache_evict(tsdn, pac, ehooks,
+	    &pac->ecache_retained, 0)) != NULL) {
+		extent_destroy_wrapper(tsdn, pac, ehooks, edata);
+	}
+}