next = rb_first(&session->hists_tree);
        while (next) {
                struct hists *hists;
-               u64 nr_hists;
 
                hists = rb_entry(next, struct hists, rb_node);
                hists__collapse_resort(hists);
-               nr_hists = hists__output_resort(hists);
+               hists__output_resort(hists);
                if (use_browser)
-                       perf_session__browse_hists(&hists->entries, nr_hists,
+                       perf_session__browse_hists(&hists->entries,
+                                                  hists->nr_entries,
                                                   hists->stats.total, help,
                                                   input_name);
                else {
 
        return self;
 }
 
+static void hists__inc_nr_entries(struct hists *self, struct hist_entry *entry)
+{
+       if (entry->ms.sym && self->max_sym_namelen < entry->ms.sym->namelen)
+               self->max_sym_namelen = entry->ms.sym->namelen;
+       ++self->nr_entries;
+}
+
 struct hist_entry *__hists__add_entry(struct hists *self,
                                      struct addr_location *al,
                                      struct symbol *sym_parent, u64 count)
                return NULL;
        rb_link_node(&he->rb_node, parent, p);
        rb_insert_color(&he->rb_node, &self->entries);
+       hists__inc_nr_entries(self, he);
 out:
        hist_entry__add_cpumode_count(he, al->cpumode, count);
        return he;
  * collapse the histogram
  */
 
-static void collapse__insert_entry(struct rb_root *root, struct hist_entry *he)
+static bool collapse__insert_entry(struct rb_root *root, struct hist_entry *he)
 {
        struct rb_node **p = &root->rb_node;
        struct rb_node *parent = NULL;
                if (!cmp) {
                        iter->count += he->count;
                        hist_entry__free(he);
-                       return;
+                       return false;
                }
 
                if (cmp < 0)
 
        rb_link_node(&he->rb_node, parent, p);
        rb_insert_color(&he->rb_node, root);
+       return true;
 }
 
 void hists__collapse_resort(struct hists *self)
 
        tmp = RB_ROOT;
        next = rb_first(&self->entries);
+       self->nr_entries = 0;
+       self->max_sym_namelen = 0;
 
        while (next) {
                n = rb_entry(next, struct hist_entry, rb_node);
                next = rb_next(&n->rb_node);
 
                rb_erase(&n->rb_node, &self->entries);
-               collapse__insert_entry(&tmp, n);
+               if (collapse__insert_entry(&tmp, n))
+                       hists__inc_nr_entries(self, n);
        }
 
        self->entries = tmp;
        rb_insert_color(&he->rb_node, entries);
 }
 
-u64 hists__output_resort(struct hists *self)
+void hists__output_resort(struct hists *self)
 {
        struct rb_root tmp;
        struct rb_node *next;
        struct hist_entry *n;
        u64 min_callchain_hits;
-       u64 nr_hists = 0;
 
        min_callchain_hits = self->stats.total * (callchain_param.min_percent / 100);
 
        tmp = RB_ROOT;
        next = rb_first(&self->entries);
 
+       self->nr_entries = 0;
+       self->max_sym_namelen = 0;
+
        while (next) {
                n = rb_entry(next, struct hist_entry, rb_node);
                next = rb_next(&n->rb_node);
 
                rb_erase(&n->rb_node, &self->entries);
                __hists__insert_output_entry(&tmp, n, min_callchain_hits);
-               ++nr_hists;
+               hists__inc_nr_entries(self, n);
        }
 
        self->entries = tmp;
-       return nr_hists;
 }
 
 static size_t callchain__fprintf_left_margin(FILE *fp, int left_margin)
 
 struct hists {
        struct rb_node          rb_node;
        struct rb_root          entries;
+       u64                     nr_entries;
        struct events_stats     stats;
        u64                     config;
        u64                     event_stream;
        u32                     type;
+       u32                     max_sym_namelen;
 };
 
 struct hist_entry *__hists__add_entry(struct hists *self,
                         long displacement, bool color, u64 total);
 void hist_entry__free(struct hist_entry *);
 
-u64 hists__output_resort(struct hists *self);
+void hists__output_resort(struct hists *self);
 void hists__collapse_resort(struct hists *self);
 size_t hists__fprintf(struct hists *self, struct hists *pair,
                      bool show_displacement, FILE *fp);