--- old/src/share/vm/gc_implementation/parNew/parCardTableModRefBS.cpp	2015-05-13 14:05:32.157074678 +0200
+++ new/src/share/vm/gc_implementation/parNew/parCardTableModRefBS.cpp	2015-05-13 14:05:32.049071087 +0200
@@ -39,16 +39,10 @@
 void CardTableModRefBS::non_clean_card_iterate_parallel_work(Space* sp, MemRegion mr,
                                                              OopsInGenClosure* cl,
                                                              CardTableRS* ct,
-                                                             int n_threads) {
+                                                             uint n_threads) {
   assert(n_threads > 0, "Error: expected n_threads > 0");
-  assert((n_threads == 1 && ParallelGCThreads == 0) ||
-         n_threads <= (int)ParallelGCThreads,
-         "# worker threads != # requested!");
-  assert(!Thread::current()->is_VM_thread() || (n_threads == 1), "There is only 1 VM thread");
-  assert(UseDynamicNumberOfGCThreads ||
-         !FLAG_IS_DEFAULT(ParallelGCThreads) ||
-         n_threads == (int)ParallelGCThreads,
-         "# worker threads != # requested!");
+  assert(n_threads <= (uint)ParallelGCThreads, "# worker threads != # requested!");
+
   // Make sure the LNC array is valid for the space.
   jbyte**   lowest_non_clean;
   uintptr_t lowest_non_clean_base_chunk_index;
@@ -64,9 +58,13 @@
   pst->set_n_threads(n_threads);
   pst->set_n_tasks(n_strides);
 
+  bool parallel = n_threads > 0;
+
   uint stride = 0;
   while (!pst->is_task_claimed(/* reference */ stride)) {
-    process_stride(sp, mr, stride, n_strides, cl, ct,
+    process_stride(sp, mr, stride, n_strides,
+	               parallel,
+                   cl, ct,
                    lowest_non_clean,
                    lowest_non_clean_base_chunk_index,
                    lowest_non_clean_chunk_size);
@@ -89,6 +87,7 @@
 process_stride(Space* sp,
                MemRegion used,
                jint stride, int n_strides,
+               bool parallel,
                OopsInGenClosure* cl,
                CardTableRS* ct,
                jbyte** lowest_non_clean,
@@ -133,8 +132,9 @@
     assert(used.contains(chunk_mr), "chunk_mr should be subset of used");
 
     DirtyCardToOopClosure* dcto_cl = sp->new_dcto_cl(cl, precision(),
-                                                     cl->gen_boundary());
-    ClearNoncleanCardWrapper clear_cl(dcto_cl, ct);
+                                                     cl->gen_boundary(),
+                                                     parallel);
+    ClearNoncleanCardWrapper clear_cl(dcto_cl, ct, parallel);
 
 
     // Process the chunk.