--- a/hotspot/src/share/vm/gc/g1/g1PageBasedVirtualSpace.cpp	Thu Sep 15 12:10:43 2016 -0400
+++ b/hotspot/src/share/vm/gc/g1/g1PageBasedVirtualSpace.cpp	Fri Sep 16 11:33:47 2016 +0200
@@ -24,8 +24,10 @@
 
 #include "precompiled.hpp"
 #include "gc/g1/g1PageBasedVirtualSpace.hpp"
+#include "gc/shared/workgroup.hpp"
 #include "oops/markOop.hpp"
 #include "oops/oop.inline.hpp"
+#include "runtime/atomic.hpp"
 #include "runtime/os.inline.hpp"
 #include "services/memTracker.hpp"
 #include "utilities/bitMap.inline.hpp"
@@ -177,7 +179,7 @@
   guarantee(start_page < end_page,
             "Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page);
 
-  os::pretouch_memory(page_start(start_page), bounded_end_addr(end_page));
+  os::pretouch_memory(page_start(start_page), bounded_end_addr(end_page), _page_size);
 }
 
 bool G1PageBasedVirtualSpace::commit(size_t start_page, size_t size_in_pages) {
@@ -198,9 +200,6 @@
   }
   _committed.set_range(start_page, end_page);
 
-  if (AlwaysPreTouch) {
-    pretouch_internal(start_page, end_page);
-  }
   return zero_filled;
 }
 
@@ -227,6 +226,53 @@
   _committed.clear_range(start_page, end_page);
 }
 
+class G1PretouchTask : public AbstractGangTask {
+private:
+  char* volatile _cur_addr;
+  char* const _start_addr;
+  char* const _end_addr;
+  size_t const _page_size;
+public:
+  G1PretouchTask(char* start_address, char* end_address, size_t page_size) :
+    AbstractGangTask("G1 PreTouch",
+                     Universe::is_fully_initialized() ? GCId::current_raw() :
+                                                        // During VM initialization there is
+                                                        // no GC cycle that this task can be
+                                                        // associated with.
+                                                        GCId::undefined()),
+    _cur_addr(start_address),
+    _start_addr(start_address),
+    _end_addr(end_address),
+    _page_size(page_size) {
+  }
+
+  virtual void work(uint worker_id) {
+    size_t const actual_chunk_size = MAX2(chunk_size(), _page_size);
+    while (true) {
+      char* touch_addr = (char*)Atomic::add_ptr((intptr_t)actual_chunk_size, (volatile void*) &_cur_addr) - actual_chunk_size;
+      if (touch_addr < _start_addr || touch_addr >= _end_addr) {
+        break;
+      }
+      char* end_addr = touch_addr + MIN2(actual_chunk_size, pointer_delta(_end_addr, touch_addr, sizeof(char)));
+      os::pretouch_memory(touch_addr, end_addr, _page_size);
+    }
+  }
+
+  static size_t chunk_size() { return PreTouchParallelChunkSize; }
+};
+
+void G1PageBasedVirtualSpace::pretouch(size_t start_page, size_t size_in_pages, WorkGang* pretouch_gang) {
+  guarantee(pretouch_gang != NULL, "No pretouch gang specified.");
+
+  size_t num_chunks = MAX2((size_t)1, size_in_pages * _page_size / MAX2(G1PretouchTask::chunk_size(), _page_size));
+
+  uint num_workers = MIN2((uint)num_chunks, pretouch_gang->active_workers());
+  G1PretouchTask cl(page_start(start_page), bounded_end_addr(start_page + size_in_pages), _page_size);
+  log_debug(gc, heap)("Running %s with %u workers for " SIZE_FORMAT " work units pre-touching " SIZE_FORMAT "B.",
+                      cl.name(), num_workers, num_chunks, size_in_pages * _page_size);
+  pretouch_gang->run_task(&cl, num_workers);
+}
+
 bool G1PageBasedVirtualSpace::contains(const void* p) const {
   return _low_boundary <= (const char*) p && (const char*) p < _high_boundary;
 }