diff a/src/hotspot/share/gc/g1/heapRegion.inline.hpp b/src/hotspot/share/gc/g1/heapRegion.inline.hpp
--- a/src/hotspot/share/gc/g1/heapRegion.inline.hpp
+++ b/src/hotspot/share/gc/g1/heapRegion.inline.hpp
@@ -164,11 +164,13 @@
 
 inline bool HeapRegion::is_obj_dead(const oop obj, const G1CMBitMap* const prev_bitmap) const {
   assert(is_in_reserved(obj), "Object " PTR_FORMAT " must be in region", p2i(obj));
   return !obj_allocated_since_prev_marking(obj) &&
          !prev_bitmap->is_marked(obj) &&
-         !is_open_archive();
+         !is_closed_archive();
+
+//  return !(obj_allocated_since_prev_marking(obj) || prev_bitmap->is_marked(obj) || is_closed_archive());
 }
 
 inline size_t HeapRegion::block_size(const HeapWord *addr) const {
   if (addr == top()) {
     return pointer_delta(end(), addr);
@@ -348,10 +350,14 @@
 
     size_t size;
     bool is_dead = is_obj_dead_with_size(obj, bitmap, &size);
     bool is_precise = false;
 
+    if (is_open_archive()) {
+      log_debug(gc)("seq_iter " PTR_FORMAT " dead %d", p2i(obj), is_dead);
+    }
+
     cur += size;
     if (!is_dead) {
       // Process live object's references.
 
       // Non-objArrays are usually marked imprecise at the object