diff --git a/examples/nvme/perf/perf.c b/examples/nvme/perf/perf.c
index e3645e0b7..71de1db5e 100644
--- a/examples/nvme/perf/perf.c
+++ b/examples/nvme/perf/perf.c
@@ -128,7 +128,7 @@ struct ns_worker_ctx {
 
 	struct ns_worker_ctx	*next;
 
-	struct spdk_histogram_data	histogram;
+	struct spdk_histogram_data	*histogram;
 };
 
 struct perf_task {
@@ -626,7 +626,7 @@ task_complete(struct perf_task *task)
 		ns_ctx->max_tsc = tsc_diff;
 	}
 	if (g_latency_sw_tracking_level > 0) {
-		spdk_histogram_data_tally(&ns_ctx->histogram, tsc_diff);
+		spdk_histogram_data_tally(ns_ctx->histogram, tsc_diff);
 	}
 
 	/*
@@ -950,7 +950,7 @@ print_performance(void)
 			printf("Summary latency data for %-43.43s from core %u:\n", ns_ctx->entry->name, worker->lcore);
 			printf("=================================================================================\n");
 
-			spdk_histogram_data_iterate(&ns_ctx->histogram, check_cutoff, &cutoff);
+			spdk_histogram_data_iterate(ns_ctx->histogram, check_cutoff, &cutoff);
 
 			printf("\n");
 			ns_ctx = ns_ctx->next;
@@ -970,7 +970,7 @@ print_performance(void)
 			printf("==============================================================================\n");
 			printf("       Range in us     Cumulative    IO count\n");
 
-			spdk_histogram_data_iterate(&ns_ctx->histogram, print_bucket, NULL);
+			spdk_histogram_data_iterate(ns_ctx->histogram, print_bucket, NULL);
 			printf("\n");
 			ns_ctx = ns_ctx->next;
 		}
@@ -1325,6 +1325,7 @@ unregister_workers(void)
 
 		while (ns_ctx) {
 			struct ns_worker_ctx *next_ns_ctx = ns_ctx->next;
+			spdk_histogram_data_free(ns_ctx->histogram);
 			free(ns_ctx);
 			ns_ctx = next_ns_ctx;
 		}
@@ -1487,7 +1488,7 @@ associate_workers_with_ns(void)
 		ns_ctx->min_tsc = UINT64_MAX;
 		ns_ctx->entry = entry;
 		ns_ctx->next = worker->ns_ctx;
-		spdk_histogram_data_reset(&ns_ctx->histogram);
+		ns_ctx->histogram = spdk_histogram_data_alloc();
 		worker->ns_ctx = ns_ctx;
 
 		worker = worker->next;
diff --git a/include/spdk/histogram_data.h b/include/spdk/histogram_data.h
index de9d8dda0..25649397a 100644
--- a/include/spdk/histogram_data.h
+++ b/include/spdk/histogram_data.h
@@ -45,11 +45,14 @@
 extern "C" {
 #endif
 
-#define SPDK_HISTOGRAM_BUCKET_SHIFT(h)		7
+#define SPDK_HISTOGRAM_BUCKET_SHIFT_DEFAULT	7
+#define SPDK_HISTOGRAM_BUCKET_SHIFT(h)		h->bucket_shift
 #define SPDK_HISTOGRAM_BUCKET_LSB(h)		(64 - SPDK_HISTOGRAM_BUCKET_SHIFT(h))
 #define SPDK_HISTOGRAM_NUM_BUCKETS_PER_RANGE(h)	(1ULL << SPDK_HISTOGRAM_BUCKET_SHIFT(h))
 #define SPDK_HISTOGRAM_BUCKET_MASK(h)		(SPDK_HISTOGRAM_NUM_BUCKETS_PER_RANGE(h) - 1)
 #define SPDK_HISTOGRAM_NUM_BUCKET_RANGES(h)	(SPDK_HISTOGRAM_BUCKET_LSB(h) + 1)
+#define SPDK_HISTOGRAM_NUM_BUCKETS(h)		(SPDK_HISTOGRAM_NUM_BUCKETS_PER_RANGE(h) * \
+						 SPDK_HISTOGRAM_NUM_BUCKET_RANGES(h))
 
 /*
  * SPDK histograms are implemented using ranges of bucket arrays.  The most common usage
@@ -83,30 +86,30 @@ extern "C" {
 
 struct spdk_histogram_data {
 
-	/*
-	 * "x" is just a filler here for now - a future patch will make this a dynamic array of
-	 *  uint64_t's and this will go away.
-	 */
-	uint64_t	bucket[SPDK_HISTOGRAM_NUM_BUCKET_RANGES(x)][SPDK_HISTOGRAM_NUM_BUCKETS_PER_RANGE(x)];
+	uint32_t	bucket_shift;
+	uint64_t	*bucket;
 
 };
 
 static inline void
 __spdk_histogram_increment(struct spdk_histogram_data *h, uint32_t range, uint32_t index)
 {
-	h->bucket[range][index]++;
+	uint64_t *count;
+
+	count = &h->bucket[(range << SPDK_HISTOGRAM_BUCKET_SHIFT(h)) + index];
+	(*count)++;
 }
 
 static inline uint64_t
 __spdk_histogram_get_count(const struct spdk_histogram_data *h, uint32_t range, uint32_t index)
 {
-	return h->bucket[range][index];
+	return h->bucket[(range << SPDK_HISTOGRAM_BUCKET_SHIFT(h)) + index];
 }
 
 static inline void
 spdk_histogram_data_reset(struct spdk_histogram_data *histogram)
 {
-	memset(histogram, 0, sizeof(*histogram));
+	memset(histogram->bucket, 0, SPDK_HISTOGRAM_NUM_BUCKETS(histogram) * sizeof(uint64_t));
 }
 
 static inline uint32_t
@@ -200,6 +203,43 @@ spdk_histogram_data_iterate(const struct spdk_histogram_data *histogram,
 	}
 }
 
+static inline struct spdk_histogram_data *
+spdk_histogram_data_alloc_sized(uint32_t bucket_shift)
+{
+	struct spdk_histogram_data *h;
+
+	h = (struct spdk_histogram_data *)calloc(1, sizeof(*h));
+	if (h == NULL) {
+		return NULL;
+	}
+
+	h->bucket_shift = bucket_shift;
+	h->bucket = (uint64_t *)calloc(SPDK_HISTOGRAM_NUM_BUCKETS(h), sizeof(uint64_t));
+	if (h->bucket == NULL) {
+		free(h);
+		return NULL;
+	}
+
+	return h;
+}
+
+static inline struct spdk_histogram_data *
+spdk_histogram_data_alloc(void)
+{
+	return spdk_histogram_data_alloc_sized(SPDK_HISTOGRAM_BUCKET_SHIFT_DEFAULT);
+}
+
+static inline void
+spdk_histogram_data_free(struct spdk_histogram_data *h)
+{
+	if (h == NULL) {
+		return;
+	}
+
+	free(h->bucket);
+	free(h);
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/test/lib/nvme/overhead/overhead.c b/test/lib/nvme/overhead/overhead.c
index d6b91686b..36c3c4ef1 100644
--- a/test/lib/nvme/overhead/overhead.c
+++ b/test/lib/nvme/overhead/overhead.c
@@ -80,8 +80,8 @@ struct ns_entry {
 	uint32_t		current_queue_depth;
 	char			name[1024];
 
-	struct spdk_histogram_data	submit_histogram;
-	struct spdk_histogram_data	complete_histogram;
+	struct spdk_histogram_data	*submit_histogram;
+	struct spdk_histogram_data	*complete_histogram;
 };
 
 struct perf_task {
@@ -150,8 +150,8 @@ register_ns(struct spdk_nvme_ctrlr *ctrlr, struct spdk_nvme_ns *ns)
 	entry->size_in_ios = spdk_nvme_ns_get_size(ns) /
 			     g_io_size_bytes;
 	entry->io_size_blocks = g_io_size_bytes / spdk_nvme_ns_get_sector_size(ns);
-	spdk_histogram_data_reset(&entry->submit_histogram);
-	spdk_histogram_data_reset(&entry->complete_histogram);
+	entry->submit_histogram = spdk_histogram_data_alloc();
+	entry->complete_histogram = spdk_histogram_data_alloc();
 
 	snprintf(entry->name, 44, "%-20.20s (%-20.20s)", cdata->mn, cdata->sn);
 
@@ -314,7 +314,7 @@ submit_single_io(void)
 		g_tsc_submit_max = tsc_submit;
 	}
 	if (g_enable_histogram) {
-		spdk_histogram_data_tally(&entry->submit_histogram, tsc_submit);
+		spdk_histogram_data_tally(entry->submit_histogram, tsc_submit);
 	}
 
 	if (rc != 0) {
@@ -369,7 +369,7 @@ check_io(void)
 			g_tsc_complete_max = tsc_complete;
 		}
 		if (g_enable_histogram) {
-			spdk_histogram_data_tally(&g_ns->complete_histogram, tsc_complete);
+			spdk_histogram_data_tally(g_ns->complete_histogram, tsc_complete);
 		}
 		g_io_completed++;
 		if (!g_ns->is_draining) {
@@ -521,13 +521,13 @@ print_stats(void)
 	printf("Submit histogram\n");
 	printf("================\n");
 	printf("       Range in us     Cumulative     Count\n");
-	spdk_histogram_data_iterate(&g_ns->submit_histogram, print_bucket, NULL);
+	spdk_histogram_data_iterate(g_ns->submit_histogram, print_bucket, NULL);
 	printf("\n");
 
 	printf("Complete histogram\n");
 	printf("==================\n");
 	printf("       Range in us     Cumulative     Count\n");
-	spdk_histogram_data_iterate(&g_ns->complete_histogram, print_bucket, NULL);
+	spdk_histogram_data_iterate(g_ns->complete_histogram, print_bucket, NULL);
 	printf("\n");
 
 }
@@ -675,6 +675,8 @@ int main(int argc, char **argv)
 	print_stats();
 
 cleanup:
+	spdk_histogram_data_free(g_ns->submit_histogram);
+	spdk_histogram_data_free(g_ns->complete_histogram);
 	free(g_ns);
 	if (g_ctrlr) {
 		spdk_nvme_detach(g_ctrlr->ctrlr);
diff --git a/test/lib/util/histogram_perf/histogram_perf.c b/test/lib/util/histogram_perf/histogram_perf.c
index fa143e38c..eeff61746 100644
--- a/test/lib/util/histogram_perf/histogram_perf.c
+++ b/test/lib/util/histogram_perf/histogram_perf.c
@@ -57,7 +57,7 @@ usage(const char *prog)
 int
 main(int argc, char **argv)
 {
-	struct spdk_histogram_data h;
+	struct spdk_histogram_data *h;
 	struct spdk_env_opts opts;
 	uint64_t tsc[128], t, end_tsc, count;
 	uint32_t i;
@@ -81,11 +81,11 @@ main(int argc, char **argv)
 
 	end_tsc = spdk_get_ticks() + (10 * spdk_get_ticks_hz());
 	count = 0;
-	spdk_histogram_data_reset(&h);
+	h = spdk_histogram_data_alloc();
 
 	while (true) {
 		t = spdk_get_ticks();
-		spdk_histogram_data_tally(&h, t - tsc[count % 128]);
+		spdk_histogram_data_tally(h, t - tsc[count % 128]);
 		count++;
 		if (t > end_tsc) {
 			break;
@@ -93,5 +93,7 @@ main(int argc, char **argv)
 	}
 
 	printf("count = %ju\n", count);
+	spdk_histogram_data_free(h);
+
 	return rc;
 }