diff -r e943ff4a475a src/hotspot/share/gc/shared/taskqueue.hpp
--- a/src/hotspot/share/gc/shared/taskqueue.hpp Tue Aug 06 08:47:32 2019 +0800
+++ b/src/hotspot/share/gc/shared/taskqueue.hpp Tue Aug 06 11:55:25 2019 +0800
@@ -268,7 +268,7 @@
 private:
   // Slow paths for push, pop_local.  (pop_global has no fast path.)
   bool push_slow(E t, uint dirty_n_elems);
-  bool pop_local_slow(uint localBot, Age oldAge);
+  bool pop_local_slow(uint localBot, Age oldAge, idx_t tp);

 public:
   typedef E element_type;
diff -r e943ff4a475a src/hotspot/share/gc/shared/taskqueue.inline.hpp
--- a/src/hotspot/share/gc/shared/taskqueue.inline.hpp  Tue Aug 06 08:47:32 2019 +0800
+++ b/src/hotspot/share/gc/shared/taskqueue.inline.hpp  Tue Aug 06 11:55:25 2019 +0800
@@ -119,7 +119,7 @@
 // gets the last task or in pop_global() if the queue wraps (top == 0
 // and pop_global() succeeds, see pop_global()).
 template<class E, MEMFLAGS F, unsigned int N>
-bool GenericTaskQueue<E, F, N>::pop_local_slow(uint localBot, Age oldAge) {
+bool GenericTaskQueue<E, F, N>::pop_local_slow(uint localBot, Age oldAge, idx_t tp) {
   // This queue was observed to contain exactly one element; either this
   // thread will claim it, or a competing "pop_global".  In either case,
   // the queue will be logically empty afterwards.  Create a new Age value
@@ -129,6 +129,9 @@
   // then have the owner thread do a pop followed by another push.  Without
   // the incrementing of "tag", the pop_global's CAS could succeed,
   // allowing it to believe it has claimed the stale element.)
+  if (oldAge.top() < tp) {
+    tty->print_cr("unreasonable oldAge: oldAge.top = %d, tp = %d, localBot = %d, N = %d", oldAge.top(), tp, localBot, N);
+  }
   Age newAge((idx_t)localBot, oldAge.tag() + 1);
   // Perhaps a competing pop_global has already incremented "top", in which
   // case it wins the element.
@@ -184,7 +187,7 @@
   } else {
     // Otherwise, the queue contained exactly one element; we take the slow
     // path.
-    return pop_local_slow(localBot, _age.get());
+    return pop_local_slow(localBot, _age.get(), tp);
   }
 }