diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index 7b48590..16f360c 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -20,9 +20,10 @@
 extern int64_t hist_entry__collapse(struct hist_entry *, struct hist_entry *);
 void hist_entry__free(struct hist_entry *);
 
-void perf_session__output_resort(struct perf_session *self, u64 total_samples);
-void perf_session__collapse_resort(struct perf_session *self);
-size_t perf_session__fprintf_hists(struct perf_session *self,
+void perf_session__output_resort(struct rb_root *hists, u64 total_samples);
+void perf_session__collapse_resort(struct rb_root *hists);
+size_t perf_session__fprintf_hists(struct rb_root *hists,
 				   struct perf_session *pair,
-				   bool show_displacement, FILE *fp);
+				   bool show_displacement, FILE *fp,
+				   u64 session_total);
 #endif	/* __PERF_HIST_H */