--- old/src/share/vm/gc/shared/workerManager.hpp	2016-07-20 13:16:02.072290534 -0700
+++ new/src/share/vm/gc/shared/workerManager.hpp	2016-07-20 13:16:01.960290538 -0700
@@ -47,11 +47,11 @@
   // threads and a failure would not be optimal but should not be fatal.
   template <class WorkerType>
   static uint add_workers (WorkerType* holder,
-                   uint active_workers,
-                   uint total_workers,
-                   uint created_workers,
-                   os::ThreadType worker_type,
-                   bool initializing) {
+                           uint active_workers,
+                           uint total_workers,
+                           uint created_workers,
+                           os::ThreadType worker_type,
+                           bool initializing) {
     uint start = created_workers;
     uint end = MIN2(active_workers, total_workers);
     for (uint worker_id = start; worker_id < end; worker_id += 1) {
@@ -61,8 +61,8 @@
       }
       if (new_worker == NULL || !os::create_thread(new_worker, worker_type)) {
         log_trace(gc, task)("WorkerManager::add_workers() : "
-           "creation failed due to failed allocation of native %s",
-           new_worker == NULL ?  "memory" : "thread");
+                            "creation failed due to failed allocation of native %s",
+                            new_worker == NULL ?  "memory" : "thread");
         if (new_worker != NULL) {
            delete new_worker;
         }
@@ -76,7 +76,7 @@
     }
 
     log_trace(gc, task)("WorkerManager::add_workers() : "
-       "created_workers: %u", created_workers);
+                        "created_workers: %u", created_workers);
 
     return created_workers;
   }
--- old/src/share/vm/gc/shared/workgroup.cpp	2016-07-20 13:16:02.708290512 -0700
+++ new/src/share/vm/gc/shared/workgroup.cpp	2016-07-20 13:16:02.580290516 -0700
@@ -271,11 +271,13 @@
             "Trying to execute task %s with %u workers which is more than the amount of total workers %u.",
             task->name(), num_workers, total_workers());
   guarantee(num_workers > 0, "Trying to execute task %s with zero workers", task->name());
-  // num_workers may have been calculated based on different criteria
-  // than _active_workers so use num_workers limited by the number of
-  // created workers.
-  uint active_workers = MIN2(_created_workers, num_workers);
-  _dispatcher->coordinator_execute_on_workers(task, active_workers);
+  uint old_num_workers = _active_workers;
+  log_debug(gc)("run_task: updating active workers for %s from %u to %u", task->name(), old_num_workers, num_workers);
+  update_active_workers(num_workers);
+  guarantee(_active_workers == num_workers, "active workers %u num_workers %u", _active_workers, num_workers);
+  _dispatcher->coordinator_execute_on_workers(task, num_workers);
+  log_debug(gc)("run_task: restoring active workers from %u to %u", num_workers, old_num_workers);
+  update_active_workers(old_num_workers);
 }
 
 AbstractGangWorker::AbstractGangWorker(AbstractWorkGang* gang, uint id) {
--- old/src/share/vm/gc/shared/workgroup.hpp	2016-07-20 13:16:03.176290495 -0700
+++ new/src/share/vm/gc/shared/workgroup.hpp	2016-07-20 13:16:03.068290499 -0700
@@ -162,8 +162,6 @@
     _active_workers = MIN2(v, _total_workers);
     add_workers(false /* exit_on_failure */);
     assert(v != 0, "Trying to set active workers to 0");
-    assert(UseDynamicNumberOfGCThreads || _active_workers == _total_workers,
-           "Unless dynamic should use total workers");
     log_info(gc, task)("GC Workers: using %d out of %d", _active_workers, _total_workers);
     return _active_workers;
   }