--- old/src/share/vm/gc/g1/g1CardCounts.cpp	2016-04-06 17:17:18.194383594 +0200
+++ new/src/share/vm/gc/g1/g1CardCounts.cpp	2016-04-06 17:17:18.098383592 +0200
@@ -83,7 +83,7 @@
   }
 }
 
-uint G1CardCounts::add_card_count(jbyte* card_ptr) {
+uint G1CardCounts::add_card_count(volatile jbyte* card_ptr) {
   // Returns the number of times the card has been refined.
   // If we failed to reserve/commit the counts table, return 0.
   // If card_ptr is beyond the committed end of the counts table,
@@ -118,11 +118,11 @@
 
 void G1CardCounts::clear_range(MemRegion mr) {
   if (has_count_table()) {
-    const jbyte* from_card_ptr = _ct_bs->byte_for_const(mr.start());
+    const volatile jbyte* from_card_ptr = _ct_bs->byte_for_const(mr.start());
     // We use the last address in the range as the range could represent the
     // last region in the heap. In which case trying to find the card will be an
     // OOB access to the card table.
-    const jbyte* last_card_ptr = _ct_bs->byte_for_const(mr.last());
+    const volatile jbyte* last_card_ptr = _ct_bs->byte_for_const(mr.last());
 
 #ifdef ASSERT
     HeapWord* start_addr = _ct_bs->addr_for(from_card_ptr);