diff --git a/Makefile.in b/Makefile.in
index 38ffbf4c..67c4d5d8 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -107,15 +107,27 @@ C_TESTLIB_SRCS := $(srcroot)test/src/math.c $(srcroot)test/src/mtx.c \
 	$(srcroot)test/src/SFMT.c $(srcroot)test/src/test.c \
 	$(srcroot)test/src/thd.c
 C_UTIL_INTEGRATION_SRCS := $(srcroot)src/util.c
-TESTS_UNIT := $(srcroot)test/unit/bitmap.c $(srcroot)test/unit/ckh.c \
-	$(srcroot)test/unit/hash.c $(srcroot)test/unit/junk.c \
-	$(srcroot)test/unit/mallctl.c $(srcroot)test/unit/math.c \
-	$(srcroot)test/unit/mq.c $(srcroot)test/unit/mtx.c \
-	$(srcroot)test/unit/ql.c $(srcroot)test/unit/qr.c \
-	$(srcroot)test/unit/quarantine.c $(srcroot)test/unit/rb.c \
-	$(srcroot)test/unit/rtree.c $(srcroot)test/unit/SFMT.c \
-	$(srcroot)test/unit/stats.c $(srcroot)test/unit/tsd.c \
-	$(srcroot)test/unit/util.c $(srcroot)test/unit/zero.c
+TESTS_UNIT := $(srcroot)test/unit/bitmap.c \
+	$(srcroot)test/unit/ckh.c \
+	$(srcroot)test/unit/hash.c \
+	$(srcroot)test/unit/junk.c \
+	$(srcroot)test/unit/mallctl.c \
+	$(srcroot)test/unit/math.c \
+	$(srcroot)test/unit/mq.c \
+	$(srcroot)test/unit/mtx.c \
+	$(srcroot)test/unit/prof_accum.c \
+	$(srcroot)test/unit/prof_gdump.c \
+	$(srcroot)test/unit/prof_idump.c \
+	$(srcroot)test/unit/ql.c \
+	$(srcroot)test/unit/qr.c \
+	$(srcroot)test/unit/quarantine.c \
+	$(srcroot)test/unit/rb.c \
+	$(srcroot)test/unit/rtree.c \
+	$(srcroot)test/unit/SFMT.c \
+	$(srcroot)test/unit/stats.c \
+	$(srcroot)test/unit/tsd.c \
+	$(srcroot)test/unit/util.c \
+	$(srcroot)test/unit/zero.c
 TESTS_INTEGRATION := $(srcroot)test/integration/aligned_alloc.c \
 	$(srcroot)test/integration/allocated.c \
 	$(srcroot)test/integration/mallocx.c \
diff --git a/include/jemalloc/internal/private_symbols.txt b/include/jemalloc/internal/private_symbols.txt
index 6cc811dd..1e64ed57 100644
--- a/include/jemalloc/internal/private_symbols.txt
+++ b/include/jemalloc/internal/private_symbols.txt
@@ -288,8 +288,10 @@ prof_backtrace
 prof_boot0
 prof_boot1
 prof_boot2
+prof_bt_count
 prof_ctx_get
 prof_ctx_set
+prof_dump_open
 prof_free
 prof_gdump
 prof_idump
diff --git a/include/jemalloc/internal/prof.h b/include/jemalloc/internal/prof.h
index 566739bb..db056fc4 100644
--- a/include/jemalloc/internal/prof.h
+++ b/include/jemalloc/internal/prof.h
@@ -225,6 +225,11 @@ extern bool	prof_promote;
 void	bt_init(prof_bt_t *bt, void **vec);
 void	prof_backtrace(prof_bt_t *bt, unsigned nignore);
 prof_thr_cnt_t	*prof_lookup(prof_bt_t *bt);
+#ifdef JEMALLOC_JET
+size_t	prof_bt_count(void);
+typedef int (prof_dump_open_t)(bool, const char *);
+extern prof_dump_open_t *prof_dump_open;
+#endif
 void	prof_idump(void);
 bool	prof_mdump(const char *filename);
 void	prof_gdump(void);
diff --git a/src/prof.c b/src/prof.c
index 0d652124..1d8ccbd6 100644
--- a/src/prof.c
+++ b/src/prof.c
@@ -646,24 +646,49 @@ prof_lookup(prof_bt_t *bt)
 	return (ret.p);
 }
 
-static bool
+#ifdef JEMALLOC_JET
+size_t
+prof_bt_count(void)
+{
+	size_t bt_count;
+	prof_tdata_t *prof_tdata;
+
+	prof_tdata = prof_tdata_get(false);
+	if ((uintptr_t)prof_tdata <= (uintptr_t)PROF_TDATA_STATE_MAX)
+		return (0);
+
+	prof_enter(prof_tdata);
+	bt_count = ckh_count(&bt2ctx);
+	prof_leave(prof_tdata);
+
+	return (bt_count);
+}
+#endif
+
+#ifdef JEMALLOC_JET
+#undef prof_dump_open
+#define	prof_dump_open JEMALLOC_N(prof_dump_open_impl)
+#endif
+static int
 prof_dump_open(bool propagate_err, const char *filename)
 {
+	int fd;
 
-	prof_dump_fd = creat(filename, 0644);
-	if (prof_dump_fd == -1) {
-		if (propagate_err == false) {
-			malloc_printf(
-			    "<jemalloc>: creat(\"%s\"), 0644) failed\n",
-			    filename);
-			if (opt_abort)
-				abort();
-		}
-		return (true);
+	fd = creat(filename, 0644);
+	if (fd == -1 && propagate_err == false) {
+		malloc_printf("<jemalloc>: creat(\"%s\"), 0644) failed\n",
+		    filename);
+		if (opt_abort)
+			abort();
 	}
 
-	return (false);
+	return (fd);
 }
+#ifdef JEMALLOC_JET
+#undef prof_dump_open
+#define	prof_dump_open JEMALLOC_N(prof_dump_open)
+prof_dump_open_t *prof_dump_open = JEMALLOC_N(prof_dump_open_impl);
+#endif
 
 static bool
 prof_dump_flush(bool propagate_err)
@@ -895,6 +920,7 @@ prof_dump_ctx(bool propagate_err, prof_ctx_t *ctx, const prof_bt_t *bt,
 		goto label_return;
 	}
 
+	ret = false;
 label_return:
 	prof_dump_ctx_cleanup_locked(ctx, ctx_ql);
 	malloc_mutex_unlock(ctx->lock);
@@ -995,7 +1021,7 @@ prof_dump(bool propagate_err, const char *filename, bool leakcheck)
 	prof_leave(prof_tdata);
 
 	/* Create dump file. */
-	if (prof_dump_open(propagate_err, filename))
+	if ((prof_dump_fd = prof_dump_open(propagate_err, filename)) == -1)
 		goto label_open_close_error;
 
 	/* Dump profile header. */
diff --git a/test/unit/prof_accum.c b/test/unit/prof_accum.c
new file mode 100644
index 00000000..b5f1c8d6
--- /dev/null
+++ b/test/unit/prof_accum.c
@@ -0,0 +1,116 @@
+#include "test/jemalloc_test.h"
+
+#define	NTHREADS		4
+#define	NALLOCS_PER_THREAD	50
+#define	DUMP_INTERVAL		1
+#define	BT_COUNT_CHECK_INTERVAL	5
+
+#ifdef JEMALLOC_PROF
+const char *malloc_conf =
+    "prof:true,prof_accum:true,prof_active:false,lg_prof_sample:0";
+#endif
+
+static int
+prof_dump_open_intercept(bool propagate_err, const char *filename)
+{
+	int fd;
+
+	fd = open("/dev/null", O_WRONLY);
+	assert_d_ne(fd, -1, "Unexpected open() failure");
+
+	return (fd);
+}
+
+#define	alloc_n_proto(n)						\
+static void	*alloc_##n(unsigned bits);
+
+#define	alloc_n_gen(n)							\
+static void *								\
+alloc_##n(unsigned bits)						\
+{									\
+									\
+	if (bits == 0) {						\
+		void *p = mallocx(1, 0);				\
+		assert_ptr_not_null(p, "Unexpected mallocx() failure");	\
+		return (p);						\
+	}								\
+									\
+	switch (bits & 0x1U) {						\
+	case 0: return (alloc_0(bits >> 1));				\
+	case 1: return (alloc_1(bits >> 1));				\
+	default: not_reached();						\
+	}								\
+}
+alloc_n_proto(0)
+alloc_n_proto(1)
+alloc_n_gen(0)
+alloc_n_gen(1)
+
+static void *
+alloc_from_permuted_backtrace(unsigned thd_ind, unsigned iteration)
+{
+
+	return (alloc_0(thd_ind*NALLOCS_PER_THREAD + iteration));
+}
+
+static void *
+thd_start(void *varg)
+{
+	unsigned thd_ind = *(unsigned *)varg;
+	size_t bt_count_prev, bt_count;
+	unsigned i_prev, i;
+
+	i_prev = 0;
+	bt_count_prev = 0;
+	for (i = 0; i < NALLOCS_PER_THREAD; i++) {
+		void *p = alloc_from_permuted_backtrace(thd_ind, i);
+		dallocx(p, 0);
+		if (i % DUMP_INTERVAL == 0) {
+			assert_d_eq(mallctl("prof.dump", NULL, NULL, NULL, 0),
+			    0, "Unexpected error while dumping heap profile");
+		}
+
+		if (i % BT_COUNT_CHECK_INTERVAL == 0 ||
+		    i+1 == NALLOCS_PER_THREAD) {
+			bt_count = prof_bt_count();
+			assert_zu_le(bt_count_prev+(i-i_prev), bt_count,
+			    "Expected larger bactrace count increase");
+			i_prev = i;
+			bt_count_prev = bt_count;
+		}
+	}
+
+	return (NULL);
+}
+
+TEST_BEGIN(test_idump)
+{
+	bool active;
+	thd_t thds[NTHREADS];
+	unsigned thd_args[NTHREADS];
+	unsigned i;
+
+	test_skip_if(!config_prof);
+
+	active = true;
+	assert_d_eq(mallctl("prof.active", NULL, NULL, &active, sizeof(active)),
+	    0, "Unexpected mallctl failure while activating profiling");
+
+	prof_dump_open = prof_dump_open_intercept;
+
+	for (i = 0; i < NTHREADS; i++) {
+		thd_args[i] = i;
+		thd_create(&thds[i], thd_start, (void *)&thd_args[i]);
+	}
+	for (i = 0; i < NTHREADS; i++)
+		thd_join(thds[i], NULL);
+}
+TEST_END
+
+int
+main(void)
+{
+
+	return (test(
+	    test_idump));
+}
diff --git a/test/unit/prof_gdump.c b/test/unit/prof_gdump.c
new file mode 100644
index 00000000..a00b1054
--- /dev/null
+++ b/test/unit/prof_gdump.c
@@ -0,0 +1,56 @@
+#include "test/jemalloc_test.h"
+
+#ifdef JEMALLOC_PROF
+const char *malloc_conf = "prof:true,prof_active:false,prof_gdump:true";
+#endif
+
+static bool did_prof_dump_open;
+
+static int
+prof_dump_open_intercept(bool propagate_err, const char *filename)
+{
+	int fd;
+
+	did_prof_dump_open = true;
+
+	fd = open("/dev/null", O_WRONLY);
+	assert_d_ne(fd, -1, "Unexpected open() failure");
+
+	return (fd);
+}
+
+TEST_BEGIN(test_gdump)
+{
+	bool active;
+	void *p, *q;
+
+	test_skip_if(!config_prof);
+
+	active = true;
+	assert_d_eq(mallctl("prof.active", NULL, NULL, &active, sizeof(active)),
+	    0, "Unexpected mallctl failure while activating profiling");
+
+	prof_dump_open = prof_dump_open_intercept;
+
+	did_prof_dump_open = false;
+	p = mallocx(chunksize, 0);
+	assert_ptr_not_null(p, "Unexpected mallocx() failure");
+	assert_true(did_prof_dump_open, "Expected a profile dump");
+
+	did_prof_dump_open = false;
+	q = mallocx(chunksize, 0);
+	assert_ptr_not_null(q, "Unexpected mallocx() failure");
+	assert_true(did_prof_dump_open, "Expected a profile dump");
+
+	dallocx(p, 0);
+	dallocx(q, 0);
+}
+TEST_END
+
+int
+main(void)
+{
+
+	return (test(
+	    test_gdump));
+}
diff --git a/test/unit/prof_idump.c b/test/unit/prof_idump.c
new file mode 100644
index 00000000..bdea53ec
--- /dev/null
+++ b/test/unit/prof_idump.c
@@ -0,0 +1,51 @@
+#include "test/jemalloc_test.h"
+
+#ifdef JEMALLOC_PROF
+const char *malloc_conf =
+    "prof:true,prof_accum:true,prof_active:false,lg_prof_sample:0,"
+    "lg_prof_interval:0";
+#endif
+
+static bool did_prof_dump_open;
+
+static int
+prof_dump_open_intercept(bool propagate_err, const char *filename)
+{
+	int fd;
+
+	did_prof_dump_open = true;
+
+	fd = open("/dev/null", O_WRONLY);
+	assert_d_ne(fd, -1, "Unexpected open() failure");
+
+	return (fd);
+}
+
+TEST_BEGIN(test_idump)
+{
+	bool active;
+	void *p;
+
+	test_skip_if(!config_prof);
+
+	active = true;
+	assert_d_eq(mallctl("prof.active", NULL, NULL, &active, sizeof(active)),
+	    0, "Unexpected mallctl failure while activating profiling");
+
+	prof_dump_open = prof_dump_open_intercept;
+
+	did_prof_dump_open = false;
+	p = mallocx(1, 0);
+	assert_ptr_not_null(p, "Unexpected mallocx() failure");
+	dallocx(p, 0);
+	assert_true(did_prof_dump_open, "Expected a profile dump");
+}
+TEST_END
+
+int
+main(void)
+{
+
+	return (test(
+	    test_idump));
+}