--- old/src/hotspot/share/gc/shared/collectedHeap.hpp	2020-08-14 20:19:31.217817276 +0200
+++ new/src/hotspot/share/gc/shared/collectedHeap.hpp	2020-08-14 20:19:31.073814688 +0200
@@ -467,11 +467,6 @@
   // Iterator for all GC threads (other than VM thread)
   virtual void gc_threads_do(ThreadClosure* tc) const = 0;
 
-  // Runs the given task with (up to) the requested number of workers.
-  // Some GCs don't support parallel worker threads and will run the
-  // task in one thread, with worker id 0.
-  void run_task_at_safepoint(AbstractGangTask* task, uint num_workers);
-
   // Print any relevant tracing info that flags imply.
   // Default implementation does nothing.
   virtual void print_tracing_info() const = 0;