--- old/src/share/vm/utilities/bitMap.cpp	2016-03-18 13:05:58.790388903 +0100
+++ new/src/share/vm/utilities/bitMap.cpp	2016-03-18 13:05:58.693386007 +0100
@@ -68,6 +68,10 @@
   }
 }
 
+void BitMap::pretouch() {
+  os::pretouch_memory((char*)word_addr(0), (char*)word_addr(size()));
+}
+
 void BitMap::set_range_within_word(idx_t beg, idx_t end) {
   // With a valid range (beg <= end), this test ensures that end != 0, as
   // required by inverted_bit_mask_for_range.  Also avoids an unnecessary write.