3 files changed, 14 insertions, 3 deletions

diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index 50c8fece1681..9b9d12bbdc1d 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -100,6 +100,8 @@ static void hist_entry__decay(struct hist_entry *he)
 
 static bool hists__decay_entry(struct hists *hists, struct hist_entry *he)
 {
+        if (he->period == 0)
+                return true;
         hists->stats.total_period -= he->period;
         hist_entry__decay(he);
         hists->stats.total_period += he->period;
@@ -114,8 +116,12 @@ void hists__decay_entries(struct hists *hists)
         while (next) {
                 n = rb_entry(next, struct hist_entry, rb_node);
                 next = rb_next(&n->rb_node);
-
-                if (hists__decay_entry(hists, n)) {
+                /*
+                 * We may be annotating this, for instance, so keep it here in
+                 * case some it gets new samples, we'll eventually free it when
+                 * the user stops browsing and it agains gets fully decayed.
+                 */
+                if (hists__decay_entry(hists, n) && !n->used) {
                         rb_erase(&n->rb_node, &hists->entries);
 
                         if (sort__need_collapse)
diff --git a/tools/perf/util/sort.h b/tools/perf/util/sort.h
index 03851e301721..3f67ae395752 100644
--- a/tools/perf/util/sort.h
+++ b/tools/perf/util/sort.h
@@ -64,6 +64,7 @@ struct hist_entry {
 
         bool                    init_have_children;
         char                    level;
+        bool                    used;
         u8                      filtered;
         struct symbol           *parent;
         union {
diff --git a/tools/perf/util/ui/browsers/hists.c b/tools/perf/util/ui/browsers/hists.c
index 9ece84353538..fdc3c90696dc 100644
--- a/tools/perf/util/ui/browsers/hists.c
+++ b/tools/perf/util/ui/browsers/hists.c
@@ -976,9 +976,13 @@ do_annotate:
                         he = hist_browser__selected_entry(browser);
                         if (he == NULL)
                                 continue;
-
+                        /*
+                         * Don't let this be freed, say, by hists__decay_entry.
+                         */
+                        he->used = true;
                         hist_entry__tui_annotate(he, evsel->idx, nr_events,
                                                  timer, arg, delay_secs);
+                        he->used = false;
                         ui_browser__update_nr_entries(&browser->b, browser->hists->nr_entries);
                 } else if (choice == browse_map)
                         map__browse(browser->selection->map);