--- libmalloc/libmalloc-409.60.6/tests/perf_realloc.c
+++ libmalloc/libmalloc-283.40.1/tests/perf_realloc.c
@@ -38,6 +38,9 @@
 	dt_stat_time_t s = dt_stat_time_create(name);
 	dt_stat_set_variable((dt_stat_t)s, "size (bytes)", (unsigned int)size);
 	dt_stat_set_variable((dt_stat_t)s, "amount (bytes)", (int)amount);
+	// rdar://problem/40417821: disable thresholds for now.
+	//dt_stat_set_variable((dt_stat_t)s, kPCFailureThresholdPctVar,
+	//		PERFCHECK_THRESHOLD_PCT);
 	dt_stat_token now = dt_stat_time_begin(s);
 
 	for (;;) {
@@ -149,6 +152,16 @@
 	realloc_tests("NoNano", false);
 }
 
+T_DECL(realloc_perf_nanov1, "realloc with nanoV1",
+	   T_META_TAG_PERF, T_META_ENVVAR("MallocNanoZone=V1"))
+{
+#if CONFIG_NANOZONE
+	realloc_tests("Nanov1", true);
+#else // CONFIG_NANOZONE
+	T_SKIP("Nano allocator not configured");
+#endif // CONFIG_NANOZONE
+}
+
 T_DECL(realloc_perf_nanov2, "realloc with nanoV2",
 	   T_META_TAG_PERF, T_META_ENVVAR("MallocNanoZone=V2"))
 {