perf top: Remove entries from entries_collapsed on decay

We were removing only when using a --sort order that needs collapsing,
while we also use it in the threaded case, causing memory corruption
because we were scribbling freed hist entries, oops.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-k16fb4jsulr7x0ixv43amb6d@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index 9b9d12b..a7193c5 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -108,7 +108,7 @@
 	return he->period == 0;
 }
 
-void hists__decay_entries(struct hists *hists)
+static void __hists__decay_entries(struct hists *hists, bool threaded)
 {
 	struct rb_node *next = rb_first(&hists->entries);
 	struct hist_entry *n;
@@ -124,7 +124,7 @@
 		if (hists__decay_entry(hists, n) && !n->used) {
 			rb_erase(&n->rb_node, &hists->entries);
 
-			if (sort__need_collapse)
+			if (sort__need_collapse || threaded)
 				rb_erase(&n->rb_node_in, &hists->entries_collapsed);
 
 			hist_entry__free(n);
@@ -133,6 +133,16 @@
 	}
 }
 
+void hists__decay_entries(struct hists *hists)
+{
+	return __hists__decay_entries(hists, false);
+}
+
+void hists__decay_entries_threaded(struct hists *hists)
+{
+	return __hists__decay_entries(hists, true);
+}
+
 /*
  * histogram, sorted on item, collects periods
  */