diff --git a/src/hotspot/share/gc/parallel/psCompactionManager.hpp b/src/hotspot/share/gc/parallel/psCompactionManager.hpp
index 613361c7039..0a404579da8 100644
--- a/src/hotspot/share/gc/parallel/psCompactionManager.hpp
+++ b/src/hotspot/share/gc/parallel/psCompactionManager.hpp
@@ -188,7 +188,6 @@ public:
   ParMarkBitMap* mark_bitmap() { return _mark_bitmap; }
 
   // Save for later processing.  Must not fail.
-  inline void push(oop obj);
   inline void push_region(size_t index);
 
   // Check mark and maybe push on marking stack.
diff --git a/src/hotspot/share/gc/parallel/psCompactionManager.inline.hpp b/src/hotspot/share/gc/parallel/psCompactionManager.inline.hpp
index 75f54caf89e..663cd83be9c 100644
--- a/src/hotspot/share/gc/parallel/psCompactionManager.inline.hpp
+++ b/src/hotspot/share/gc/parallel/psCompactionManager.inline.hpp
@@ -56,10 +56,6 @@ inline bool ParCompactionManager::steal(int queue_num, size_t& region) {
   return region_task_queues()->steal(queue_num, region);
 }
 
-inline void ParCompactionManager::push(oop obj) {
-  marking_stack()->push(ScannerTask(obj));
-}
-
 void ParCompactionManager::push_region(size_t index)
 {
 #ifdef ASSERT
@@ -74,24 +70,26 @@ void ParCompactionManager::push_region(size_t index)
 template <typename T>
 inline void ParCompactionManager::mark_and_push(T* p) {
   T heap_oop = RawAccess<>::oop_load(p);
-  if (!CompressedOops::is_null(heap_oop)) {
-    oop obj = CompressedOops::decode_not_null(heap_oop);
-    assert(ParallelScavengeHeap::heap()->is_in(obj), "should be in heap");
-
-    if (mark_bitmap()->mark_obj(obj)) {
-      if (StringDedup::is_enabled() &&
-          java_lang_String::is_instance(obj) &&
-          psStringDedup::is_candidate_from_mark(obj)) {
-        _string_dedup_requests.add(obj);
-      }
-
-      ContinuationGCSupport::transform_stack_chunk(obj);
-
-      assert(_marking_stats_cache != nullptr, "inv");
-      _marking_stats_cache->push(obj, obj->size());
-      push(obj);
-    }
+  if (CompressedOops::is_null(heap_oop)) {
+    return;
   }
+
+  oop obj = CompressedOops::decode_not_null(heap_oop);
+  if (!mark_bitmap()->mark_obj(obj)) {
+    // Marked by another worker.
+    return;
+  }
+
+  if (StringDedup::is_enabled() &&
+      java_lang_String::is_instance(obj) &&
+      psStringDedup::is_candidate_from_mark(obj)) {
+    _string_dedup_requests.add(obj);
+  }
+
+  ContinuationGCSupport::transform_stack_chunk(obj);
+
+  _marking_stats_cache->push(obj, obj->size());
+  marking_stack()->push(ScannerTask(obj));
 }
 
 inline void ParCompactionManager::FollowStackClosure::do_void() {