diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index 5ec5de9..4b734c7 100644
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -116,7 +116,7 @@
 		return 0;
 	}
 
-	he = __perf_session__add_hist_entry(self, al, NULL, count, &hit);
+	he = __perf_session__add_hist_entry(&self->hists, al, NULL, count, &hit);
 	if (he == NULL)
 		return -ENOMEM;
 
diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 18b3f50..20df735 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -26,7 +26,8 @@
 					struct addr_location *al, u64 count)
 {
 	bool hit;
-	struct hist_entry *he = __perf_session__add_hist_entry(self, al, NULL,
+	struct hist_entry *he = __perf_session__add_hist_entry(&self->hists,
+							       al, NULL,
 							       count, &hit);
 	if (he == NULL)
 		return -ENOMEM;
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index cfc655d..cd16e6a 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -56,7 +56,8 @@
 	if ((sort__has_parent || symbol_conf.use_callchain) && chain)
 		syms = perf_session__resolve_callchain(self, al->thread,
 						       chain, &parent);
-	he = __perf_session__add_hist_entry(self, al, parent, count, &hit);
+	he = __perf_session__add_hist_entry(&self->hists, al, parent,
+					    count, &hit);
 	if (he == NULL)
 		return -ENOMEM;
 
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index e8daf5c..55dd911 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -12,12 +12,12 @@
  * histogram, sorted on item, collects counts
  */
 
-struct hist_entry *__perf_session__add_hist_entry(struct perf_session *self,
+struct hist_entry *__perf_session__add_hist_entry(struct rb_root *hists,
 						  struct addr_location *al,
 						  struct symbol *sym_parent,
 						  u64 count, bool *hit)
 {
-	struct rb_node **p = &self->hists.rb_node;
+	struct rb_node **p = &hists->rb_node;
 	struct rb_node *parent = NULL;
 	struct hist_entry *he;
 	struct hist_entry entry = {
@@ -53,7 +53,7 @@
 		return NULL;
 	*he = entry;
 	rb_link_node(&he->rb_node, parent, p);
-	rb_insert_color(&he->rb_node, &self->hists);
+	rb_insert_color(&he->rb_node, hists);
 	*hit = false;
 	return he;
 }
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index e5f99b2..7b48590 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -10,8 +10,9 @@
 struct hist_entry;
 struct addr_location;
 struct symbol;
+struct rb_root;
 
-struct hist_entry *__perf_session__add_hist_entry(struct perf_session *self,
+struct hist_entry *__perf_session__add_hist_entry(struct rb_root *hists,
 						  struct addr_location *al,
 						  struct symbol *parent,
 						  u64 count, bool *hit);