Adding upstream version 5:7.2.4.upstream/5%7.2.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 600 insertions, 0 deletions

diff --git a/deps/jemalloc/src/prof_recent.c b/deps/jemalloc/src/prof_recent.c
new file mode 100644
index 0000000..834a944
--- /dev/null
+++ b/deps/jemalloc/src/prof_recent.c
@@ -0,0 +1,600 @@
+#include "jemalloc/internal/jemalloc_preamble.h"
+#include "jemalloc/internal/jemalloc_internal_includes.h"
+
+#include "jemalloc/internal/assert.h"
+#include "jemalloc/internal/buf_writer.h"
+#include "jemalloc/internal/emitter.h"
+#include "jemalloc/internal/prof_data.h"
+#include "jemalloc/internal/prof_recent.h"
+
+ssize_t opt_prof_recent_alloc_max = PROF_RECENT_ALLOC_MAX_DEFAULT;
+malloc_mutex_t prof_recent_alloc_mtx; /* Protects the fields below */
+static atomic_zd_t prof_recent_alloc_max;
+static ssize_t prof_recent_alloc_count = 0;
+prof_recent_list_t prof_recent_alloc_list;
+
+malloc_mutex_t prof_recent_dump_mtx; /* Protects dumping. */
+
+static void
+prof_recent_alloc_max_init() {
+	atomic_store_zd(&prof_recent_alloc_max, opt_prof_recent_alloc_max,
+	    ATOMIC_RELAXED);
+}
+
+static inline ssize_t
+prof_recent_alloc_max_get_no_lock() {
+	return atomic_load_zd(&prof_recent_alloc_max, ATOMIC_RELAXED);
+}
+
+static inline ssize_t
+prof_recent_alloc_max_get(tsd_t *tsd) {
+	malloc_mutex_assert_owner(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	return prof_recent_alloc_max_get_no_lock();
+}
+
+static inline ssize_t
+prof_recent_alloc_max_update(tsd_t *tsd, ssize_t max) {
+	malloc_mutex_assert_owner(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	ssize_t old_max = prof_recent_alloc_max_get(tsd);
+	atomic_store_zd(&prof_recent_alloc_max, max, ATOMIC_RELAXED);
+	return old_max;
+}
+
+static prof_recent_t *
+prof_recent_allocate_node(tsdn_t *tsdn) {
+	return (prof_recent_t *)iallocztm(tsdn, sizeof(prof_recent_t),
+	    sz_size2index(sizeof(prof_recent_t)), false, NULL, true,
+	    arena_get(tsdn, 0, false), true);
+}
+
+static void
+prof_recent_free_node(tsdn_t *tsdn, prof_recent_t *node) {
+	assert(node != NULL);
+	assert(isalloc(tsdn, node) == sz_s2u(sizeof(prof_recent_t)));
+	idalloctm(tsdn, node, NULL, NULL, true, true);
+}
+
+static inline void
+increment_recent_count(tsd_t *tsd, prof_tctx_t *tctx) {
+	malloc_mutex_assert_owner(tsd_tsdn(tsd), tctx->tdata->lock);
+	++tctx->recent_count;
+	assert(tctx->recent_count > 0);
+}
+
+bool
+prof_recent_alloc_prepare(tsd_t *tsd, prof_tctx_t *tctx) {
+	cassert(config_prof);
+	assert(opt_prof && prof_booted);
+	malloc_mutex_assert_owner(tsd_tsdn(tsd), tctx->tdata->lock);
+	malloc_mutex_assert_not_owner(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+
+	/*
+	 * Check whether last-N mode is turned on without trying to acquire the
+	 * lock, so as to optimize for the following two scenarios:
+	 * (1) Last-N mode is switched off;
+	 * (2) Dumping, during which last-N mode is temporarily turned off so
+	 *     as not to block sampled allocations.
+	 */
+	if (prof_recent_alloc_max_get_no_lock() == 0) {
+		return false;
+	}
+
+	/*
+	 * Increment recent_count to hold the tctx so that it won't be gone
+	 * even after tctx->tdata->lock is released.  This acts as a
+	 * "placeholder"; the real recording of the allocation requires a lock
+	 * on prof_recent_alloc_mtx and is done in prof_recent_alloc (when
+	 * tctx->tdata->lock has been released).
+	 */
+	increment_recent_count(tsd, tctx);
+	return true;
+}
+
+static void
+decrement_recent_count(tsd_t *tsd, prof_tctx_t *tctx) {
+	malloc_mutex_assert_not_owner(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	assert(tctx != NULL);
+	malloc_mutex_lock(tsd_tsdn(tsd), tctx->tdata->lock);
+	assert(tctx->recent_count > 0);
+	--tctx->recent_count;
+	prof_tctx_try_destroy(tsd, tctx);
+}
+
+static inline edata_t *
+prof_recent_alloc_edata_get_no_lock(const prof_recent_t *n) {
+	return (edata_t *)atomic_load_p(&n->alloc_edata, ATOMIC_ACQUIRE);
+}
+
+edata_t *
+prof_recent_alloc_edata_get_no_lock_test(const prof_recent_t *n) {
+	cassert(config_prof);
+	return prof_recent_alloc_edata_get_no_lock(n);
+}
+
+static inline edata_t *
+prof_recent_alloc_edata_get(tsd_t *tsd, const prof_recent_t *n) {
+	malloc_mutex_assert_owner(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	return prof_recent_alloc_edata_get_no_lock(n);
+}
+
+static void
+prof_recent_alloc_edata_set(tsd_t *tsd, prof_recent_t *n, edata_t *edata) {
+	malloc_mutex_assert_owner(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	atomic_store_p(&n->alloc_edata, edata, ATOMIC_RELEASE);
+}
+
+void
+edata_prof_recent_alloc_init(edata_t *edata) {
+	cassert(config_prof);
+	edata_prof_recent_alloc_set_dont_call_directly(edata, NULL);
+}
+
+static inline prof_recent_t *
+edata_prof_recent_alloc_get_no_lock(const edata_t *edata) {
+	cassert(config_prof);
+	return edata_prof_recent_alloc_get_dont_call_directly(edata);
+}
+
+prof_recent_t *
+edata_prof_recent_alloc_get_no_lock_test(const edata_t *edata) {
+	cassert(config_prof);
+	return edata_prof_recent_alloc_get_no_lock(edata);
+}
+
+static inline prof_recent_t *
+edata_prof_recent_alloc_get(tsd_t *tsd, const edata_t *edata) {
+	malloc_mutex_assert_owner(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	prof_recent_t *recent_alloc =
+	    edata_prof_recent_alloc_get_no_lock(edata);
+	assert(recent_alloc == NULL ||
+	    prof_recent_alloc_edata_get(tsd, recent_alloc) == edata);
+	return recent_alloc;
+}
+
+static prof_recent_t *
+edata_prof_recent_alloc_update_internal(tsd_t *tsd, edata_t *edata,
+    prof_recent_t *recent_alloc) {
+	malloc_mutex_assert_owner(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	prof_recent_t *old_recent_alloc =
+	    edata_prof_recent_alloc_get(tsd, edata);
+	edata_prof_recent_alloc_set_dont_call_directly(edata, recent_alloc);
+	return old_recent_alloc;
+}
+
+static void
+edata_prof_recent_alloc_set(tsd_t *tsd, edata_t *edata,
+    prof_recent_t *recent_alloc) {
+	malloc_mutex_assert_owner(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	assert(recent_alloc != NULL);
+	prof_recent_t *old_recent_alloc =
+	    edata_prof_recent_alloc_update_internal(tsd, edata, recent_alloc);
+	assert(old_recent_alloc == NULL);
+	prof_recent_alloc_edata_set(tsd, recent_alloc, edata);
+}
+
+static void
+edata_prof_recent_alloc_reset(tsd_t *tsd, edata_t *edata,
+    prof_recent_t *recent_alloc) {
+	malloc_mutex_assert_owner(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	assert(recent_alloc != NULL);
+	prof_recent_t *old_recent_alloc =
+	    edata_prof_recent_alloc_update_internal(tsd, edata, NULL);
+	assert(old_recent_alloc == recent_alloc);
+	assert(edata == prof_recent_alloc_edata_get(tsd, recent_alloc));
+	prof_recent_alloc_edata_set(tsd, recent_alloc, NULL);
+}
+
+/*
+ * This function should be called right before an allocation is released, so
+ * that the associated recent allocation record can contain the following
+ * information:
+ * (1) The allocation is released;
+ * (2) The time of the deallocation; and
+ * (3) The prof_tctx associated with the deallocation.
+ */
+void
+prof_recent_alloc_reset(tsd_t *tsd, edata_t *edata) {
+	cassert(config_prof);
+	/*
+	 * Check whether the recent allocation record still exists without
+	 * trying to acquire the lock.
+	 */
+	if (edata_prof_recent_alloc_get_no_lock(edata) == NULL) {
+		return;
+	}
+
+	prof_tctx_t *dalloc_tctx = prof_tctx_create(tsd);
+	/*
+	 * In case dalloc_tctx is NULL, e.g. due to OOM, we will not record the
+	 * deallocation time / tctx, which is handled later, after we check
+	 * again when holding the lock.
+	 */
+
+	if (dalloc_tctx != NULL) {
+		malloc_mutex_lock(tsd_tsdn(tsd), dalloc_tctx->tdata->lock);
+		increment_recent_count(tsd, dalloc_tctx);
+		dalloc_tctx->prepared = false;
+		malloc_mutex_unlock(tsd_tsdn(tsd), dalloc_tctx->tdata->lock);
+	}
+
+	malloc_mutex_lock(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	/* Check again after acquiring the lock.  */
+	prof_recent_t *recent = edata_prof_recent_alloc_get(tsd, edata);
+	if (recent != NULL) {
+		assert(nstime_equals_zero(&recent->dalloc_time));
+		assert(recent->dalloc_tctx == NULL);
+		if (dalloc_tctx != NULL) {
+			nstime_prof_update(&recent->dalloc_time);
+			recent->dalloc_tctx = dalloc_tctx;
+			dalloc_tctx = NULL;
+		}
+		edata_prof_recent_alloc_reset(tsd, edata, recent);
+	}
+	malloc_mutex_unlock(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+
+	if (dalloc_tctx != NULL) {
+		/* We lost the rase - the allocation record was just gone. */
+		decrement_recent_count(tsd, dalloc_tctx);
+	}
+}
+
+static void
+prof_recent_alloc_evict_edata(tsd_t *tsd, prof_recent_t *recent_alloc) {
+	malloc_mutex_assert_owner(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	edata_t *edata = prof_recent_alloc_edata_get(tsd, recent_alloc);
+	if (edata != NULL) {
+		edata_prof_recent_alloc_reset(tsd, edata, recent_alloc);
+	}
+}
+
+static bool
+prof_recent_alloc_is_empty(tsd_t *tsd) {
+	malloc_mutex_assert_owner(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	if (ql_empty(&prof_recent_alloc_list)) {
+		assert(prof_recent_alloc_count == 0);
+		return true;
+	} else {
+		assert(prof_recent_alloc_count > 0);
+		return false;
+	}
+}
+
+static void
+prof_recent_alloc_assert_count(tsd_t *tsd) {
+	malloc_mutex_assert_owner(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	if (!config_debug) {
+		return;
+	}
+	ssize_t count = 0;
+	prof_recent_t *n;
+	ql_foreach(n, &prof_recent_alloc_list, link) {
+		++count;
+	}
+	assert(count == prof_recent_alloc_count);
+	assert(prof_recent_alloc_max_get(tsd) == -1 ||
+	    count <= prof_recent_alloc_max_get(tsd));
+}
+
+void
+prof_recent_alloc(tsd_t *tsd, edata_t *edata, size_t size, size_t usize) {
+	cassert(config_prof);
+	assert(edata != NULL);
+	prof_tctx_t *tctx = edata_prof_tctx_get(edata);
+
+	malloc_mutex_assert_not_owner(tsd_tsdn(tsd), tctx->tdata->lock);
+	malloc_mutex_lock(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	prof_recent_alloc_assert_count(tsd);
+
+	/*
+	 * Reserve a new prof_recent_t node if needed.  If needed, we release
+	 * the prof_recent_alloc_mtx lock and allocate.  Then, rather than
+	 * immediately checking for OOM, we regain the lock and try to make use
+	 * of the reserve node if needed.  There are six scenarios:
+	 *
+	 *          \ now | no need | need but OOMed | need and allocated
+	 *     later \    |         |                |
+	 *    ------------------------------------------------------------
+	 *     no need    |   (1)   |      (2)       |         (3)
+	 *    ------------------------------------------------------------
+	 *     need       |   (4)   |      (5)       |         (6)
+	 *
+	 * First, "(4)" never happens, because we don't release the lock in the
+	 * middle if there's no need for a new node; in such cases "(1)" always
+	 * takes place, which is trivial.
+	 *
+	 * Out of the remaining four scenarios, "(6)" is the common case and is
+	 * trivial.  "(5)" is also trivial, in which case we'll rollback the
+	 * effect of prof_recent_alloc_prepare() as expected.
+	 *
+	 * "(2)" / "(3)" occurs when the need for a new node is gone after we
+	 * regain the lock.  If the new node is successfully allocated, i.e. in
+	 * the case of "(3)", we'll release it in the end; otherwise, i.e. in
+	 * the case of "(2)", we do nothing - we're lucky that the OOM ends up
+	 * doing no harm at all.
+	 *
+	 * Therefore, the only performance cost of the "release lock" ->
+	 * "allocate" -> "regain lock" design is the "(3)" case, but it happens
+	 * very rarely, so the cost is relatively small compared to the gain of
+	 * not having to have the lock order of prof_recent_alloc_mtx above all
+	 * the allocation locks.
+	 */
+	prof_recent_t *reserve = NULL;
+	if (prof_recent_alloc_max_get(tsd) == -1 ||
+	    prof_recent_alloc_count < prof_recent_alloc_max_get(tsd)) {
+		assert(prof_recent_alloc_max_get(tsd) != 0);
+		malloc_mutex_unlock(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+		reserve = prof_recent_allocate_node(tsd_tsdn(tsd));
+		malloc_mutex_lock(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+		prof_recent_alloc_assert_count(tsd);
+	}
+
+	if (prof_recent_alloc_max_get(tsd) == 0) {
+		assert(prof_recent_alloc_is_empty(tsd));
+		goto label_rollback;
+	}
+
+	prof_tctx_t *old_alloc_tctx, *old_dalloc_tctx;
+	if (prof_recent_alloc_count == prof_recent_alloc_max_get(tsd)) {
+		/* If upper limit is reached, rotate the head. */
+		assert(prof_recent_alloc_max_get(tsd) != -1);
+		assert(!prof_recent_alloc_is_empty(tsd));
+		prof_recent_t *head = ql_first(&prof_recent_alloc_list);
+		old_alloc_tctx = head->alloc_tctx;
+		assert(old_alloc_tctx != NULL);
+		old_dalloc_tctx = head->dalloc_tctx;
+		prof_recent_alloc_evict_edata(tsd, head);
+		ql_rotate(&prof_recent_alloc_list, link);
+	} else {
+		/* Otherwise make use of the new node. */
+		assert(prof_recent_alloc_max_get(tsd) == -1 ||
+		    prof_recent_alloc_count < prof_recent_alloc_max_get(tsd));
+		if (reserve == NULL) {
+			goto label_rollback;
+		}
+		ql_elm_new(reserve, link);
+		ql_tail_insert(&prof_recent_alloc_list, reserve, link);
+		reserve = NULL;
+		old_alloc_tctx = NULL;
+		old_dalloc_tctx = NULL;
+		++prof_recent_alloc_count;
+	}
+
+	/* Fill content into the tail node. */
+	prof_recent_t *tail = ql_last(&prof_recent_alloc_list, link);
+	assert(tail != NULL);
+	tail->size = size;
+	tail->usize = usize;
+	nstime_copy(&tail->alloc_time, edata_prof_alloc_time_get(edata));
+	tail->alloc_tctx = tctx;
+	nstime_init_zero(&tail->dalloc_time);
+	tail->dalloc_tctx = NULL;
+	edata_prof_recent_alloc_set(tsd, edata, tail);
+
+	assert(!prof_recent_alloc_is_empty(tsd));
+	prof_recent_alloc_assert_count(tsd);
+	malloc_mutex_unlock(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+
+	if (reserve != NULL) {
+		prof_recent_free_node(tsd_tsdn(tsd), reserve);
+	}
+
+	/*
+	 * Asynchronously handle the tctx of the old node, so that there's no
+	 * simultaneous holdings of prof_recent_alloc_mtx and tdata->lock.
+	 * In the worst case this may delay the tctx release but it's better
+	 * than holding prof_recent_alloc_mtx for longer.
+	 */
+	if (old_alloc_tctx != NULL) {
+		decrement_recent_count(tsd, old_alloc_tctx);
+	}
+	if (old_dalloc_tctx != NULL) {
+		decrement_recent_count(tsd, old_dalloc_tctx);
+	}
+	return;
+
+label_rollback:
+	assert(edata_prof_recent_alloc_get(tsd, edata) == NULL);
+	prof_recent_alloc_assert_count(tsd);
+	malloc_mutex_unlock(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	if (reserve != NULL) {
+		prof_recent_free_node(tsd_tsdn(tsd), reserve);
+	}
+	decrement_recent_count(tsd, tctx);
+}
+
+ssize_t
+prof_recent_alloc_max_ctl_read() {
+	cassert(config_prof);
+	/* Don't bother to acquire the lock. */
+	return prof_recent_alloc_max_get_no_lock();
+}
+
+static void
+prof_recent_alloc_restore_locked(tsd_t *tsd, prof_recent_list_t *to_delete) {
+	malloc_mutex_assert_owner(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	ssize_t max = prof_recent_alloc_max_get(tsd);
+	if (max == -1 || prof_recent_alloc_count <= max) {
+		/* Easy case - no need to alter the list. */
+		ql_new(to_delete);
+		prof_recent_alloc_assert_count(tsd);
+		return;
+	}
+
+	prof_recent_t *node;
+	ql_foreach(node, &prof_recent_alloc_list, link) {
+		if (prof_recent_alloc_count == max) {
+			break;
+		}
+		prof_recent_alloc_evict_edata(tsd, node);
+		--prof_recent_alloc_count;
+	}
+	assert(prof_recent_alloc_count == max);
+
+	ql_move(to_delete, &prof_recent_alloc_list);
+	if (max == 0) {
+		assert(node == NULL);
+	} else {
+		assert(node != NULL);
+		ql_split(to_delete, node, &prof_recent_alloc_list, link);
+	}
+	assert(!ql_empty(to_delete));
+	prof_recent_alloc_assert_count(tsd);
+}
+
+static void
+prof_recent_alloc_async_cleanup(tsd_t *tsd, prof_recent_list_t *to_delete) {
+	malloc_mutex_assert_not_owner(tsd_tsdn(tsd), &prof_recent_dump_mtx);
+	malloc_mutex_assert_not_owner(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	while (!ql_empty(to_delete)) {
+		prof_recent_t *node = ql_first(to_delete);
+		ql_remove(to_delete, node, link);
+		decrement_recent_count(tsd, node->alloc_tctx);
+		if (node->dalloc_tctx != NULL) {
+			decrement_recent_count(tsd, node->dalloc_tctx);
+		}
+		prof_recent_free_node(tsd_tsdn(tsd), node);
+	}
+}
+
+ssize_t
+prof_recent_alloc_max_ctl_write(tsd_t *tsd, ssize_t max) {
+	cassert(config_prof);
+	assert(max >= -1);
+	malloc_mutex_lock(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	prof_recent_alloc_assert_count(tsd);
+	const ssize_t old_max = prof_recent_alloc_max_update(tsd, max);
+	prof_recent_list_t to_delete;
+	prof_recent_alloc_restore_locked(tsd, &to_delete);
+	malloc_mutex_unlock(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	prof_recent_alloc_async_cleanup(tsd, &to_delete);
+	return old_max;
+}
+
+static void
+prof_recent_alloc_dump_bt(emitter_t *emitter, prof_tctx_t *tctx) {
+	char bt_buf[2 * sizeof(intptr_t) + 3];
+	char *s = bt_buf;
+	assert(tctx != NULL);
+	prof_bt_t *bt = &tctx->gctx->bt;
+	for (size_t i = 0; i < bt->len; ++i) {
+		malloc_snprintf(bt_buf, sizeof(bt_buf), "%p", bt->vec[i]);
+		emitter_json_value(emitter, emitter_type_string, &s);
+	}
+}
+
+static void
+prof_recent_alloc_dump_node(emitter_t *emitter, prof_recent_t *node) {
+	emitter_json_object_begin(emitter);
+
+	emitter_json_kv(emitter, "size", emitter_type_size, &node->size);
+	emitter_json_kv(emitter, "usize", emitter_type_size, &node->usize);
+	bool released = prof_recent_alloc_edata_get_no_lock(node) == NULL;
+	emitter_json_kv(emitter, "released", emitter_type_bool, &released);
+
+	emitter_json_kv(emitter, "alloc_thread_uid", emitter_type_uint64,
+	    &node->alloc_tctx->thr_uid);
+	prof_tdata_t *alloc_tdata = node->alloc_tctx->tdata;
+	assert(alloc_tdata != NULL);
+	if (alloc_tdata->thread_name != NULL) {
+		emitter_json_kv(emitter, "alloc_thread_name",
+		    emitter_type_string, &alloc_tdata->thread_name);
+	}
+	uint64_t alloc_time_ns = nstime_ns(&node->alloc_time);
+	emitter_json_kv(emitter, "alloc_time", emitter_type_uint64,
+	    &alloc_time_ns);
+	emitter_json_array_kv_begin(emitter, "alloc_trace");
+	prof_recent_alloc_dump_bt(emitter, node->alloc_tctx);
+	emitter_json_array_end(emitter);
+
+	if (released && node->dalloc_tctx != NULL) {
+		emitter_json_kv(emitter, "dalloc_thread_uid",
+		    emitter_type_uint64, &node->dalloc_tctx->thr_uid);
+		prof_tdata_t *dalloc_tdata = node->dalloc_tctx->tdata;
+		assert(dalloc_tdata != NULL);
+		if (dalloc_tdata->thread_name != NULL) {
+			emitter_json_kv(emitter, "dalloc_thread_name",
+			    emitter_type_string, &dalloc_tdata->thread_name);
+		}
+		assert(!nstime_equals_zero(&node->dalloc_time));
+		uint64_t dalloc_time_ns = nstime_ns(&node->dalloc_time);
+		emitter_json_kv(emitter, "dalloc_time", emitter_type_uint64,
+		    &dalloc_time_ns);
+		emitter_json_array_kv_begin(emitter, "dalloc_trace");
+		prof_recent_alloc_dump_bt(emitter, node->dalloc_tctx);
+		emitter_json_array_end(emitter);
+	}
+
+	emitter_json_object_end(emitter);
+}
+
+#define PROF_RECENT_PRINT_BUFSIZE 65536
+JEMALLOC_COLD
+void
+prof_recent_alloc_dump(tsd_t *tsd, write_cb_t *write_cb, void *cbopaque) {
+	cassert(config_prof);
+	malloc_mutex_lock(tsd_tsdn(tsd), &prof_recent_dump_mtx);
+	buf_writer_t buf_writer;
+	buf_writer_init(tsd_tsdn(tsd), &buf_writer, write_cb, cbopaque, NULL,
+	    PROF_RECENT_PRINT_BUFSIZE);
+	emitter_t emitter;
+	emitter_init(&emitter, emitter_output_json_compact, buf_writer_cb,
+	    &buf_writer);
+	prof_recent_list_t temp_list;
+
+	malloc_mutex_lock(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	prof_recent_alloc_assert_count(tsd);
+	ssize_t dump_max = prof_recent_alloc_max_get(tsd);
+	ql_move(&temp_list, &prof_recent_alloc_list);
+	ssize_t dump_count = prof_recent_alloc_count;
+	prof_recent_alloc_count = 0;
+	prof_recent_alloc_assert_count(tsd);
+	malloc_mutex_unlock(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+
+	emitter_begin(&emitter);
+	uint64_t sample_interval = (uint64_t)1U << lg_prof_sample;
+	emitter_json_kv(&emitter, "sample_interval", emitter_type_uint64,
+	    &sample_interval);
+	emitter_json_kv(&emitter, "recent_alloc_max", emitter_type_ssize,
+	    &dump_max);
+	emitter_json_array_kv_begin(&emitter, "recent_alloc");
+	prof_recent_t *node;
+	ql_foreach(node, &temp_list, link) {
+		prof_recent_alloc_dump_node(&emitter, node);
+	}
+	emitter_json_array_end(&emitter);
+	emitter_end(&emitter);
+
+	malloc_mutex_lock(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+	prof_recent_alloc_assert_count(tsd);
+	ql_concat(&temp_list, &prof_recent_alloc_list, link);
+	ql_move(&prof_recent_alloc_list, &temp_list);
+	prof_recent_alloc_count += dump_count;
+	prof_recent_alloc_restore_locked(tsd, &temp_list);
+	malloc_mutex_unlock(tsd_tsdn(tsd), &prof_recent_alloc_mtx);
+
+	buf_writer_terminate(tsd_tsdn(tsd), &buf_writer);
+	malloc_mutex_unlock(tsd_tsdn(tsd), &prof_recent_dump_mtx);
+
+	prof_recent_alloc_async_cleanup(tsd, &temp_list);
+}
+#undef PROF_RECENT_PRINT_BUFSIZE
+
+bool
+prof_recent_init() {
+	cassert(config_prof);
+	prof_recent_alloc_max_init();
+
+	if (malloc_mutex_init(&prof_recent_alloc_mtx, "prof_recent_alloc",
+	    WITNESS_RANK_PROF_RECENT_ALLOC, malloc_mutex_rank_exclusive)) {
+		return true;
+	}
+
+	if (malloc_mutex_init(&prof_recent_dump_mtx, "prof_recent_dump",
+	    WITNESS_RANK_PROF_RECENT_DUMP, malloc_mutex_rank_exclusive)) {
+		return true;
+	}
+
+	ql_new(&prof_recent_alloc_list);
+
+	return false;
+}