--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp	Fri Jun 20 11:47:53 2008 -0700
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp	Fri Jun 20 13:59:55 2008 -0700
@@ -1004,6 +1004,9 @@
 
   DEBUG_ONLY(mark_bitmap()->verify_clear();)
   DEBUG_ONLY(summary_data().verify_clear();)
+
+  // Have worker threads release resources the next time they run a task.
+  gc_task_manager()->release_all_resources();
 }
 
 void PSParallelCompact::post_compact()
@@ -1949,12 +1952,6 @@
   TimeStamp compaction_start;
   TimeStamp collection_exit;
 
-  // "serial_CM" is needed until the parallel implementation
-  // of the move and update is done.
-  ParCompactionManager* serial_CM = new ParCompactionManager();
-  // Don't initialize more than once.
-  // serial_CM->initialize(&summary_data(), mark_bitmap());
-
   ParallelScavengeHeap* heap = gc_heap();
   GCCause::Cause gc_cause = heap->gc_cause();
   PSYoungGen* young_gen = heap->young_gen();
@@ -1969,6 +1966,10 @@
   PreGCValues pre_gc_values;
   pre_compact(&pre_gc_values);
 
+  // Get the compaction manager reserved for the VM thread.
+  ParCompactionManager* const vmthread_cm =
+    ParCompactionManager::manager_array(gc_task_manager()->workers());
+
   // Place after pre_compact() where the number of invocations is incremented.
   AdaptiveSizePolicyOutput(size_policy, heap->total_collections());
 
@@ -2008,7 +2009,7 @@
     bool marked_for_unloading = false;
 
     marking_start.update();
-    marking_phase(serial_CM, maximum_heap_compaction);
+    marking_phase(vmthread_cm, maximum_heap_compaction);
 
 #ifndef PRODUCT
     if (TraceParallelOldGCMarkingPhase) {
@@ -2039,7 +2040,7 @@
 #endif
 
     bool max_on_system_gc = UseMaximumCompactionOnSystemGC && is_system_gc;
-    summary_phase(serial_CM, maximum_heap_compaction || max_on_system_gc);
+    summary_phase(vmthread_cm, maximum_heap_compaction || max_on_system_gc);
 
 #ifdef ASSERT
     if (VerifyParallelOldWithMarkSweep &&
@@ -2067,13 +2068,13 @@
       // code can use the the forwarding pointers to
       // check the new pointer calculation.  The restore_marks()
       // has to be done before the real compact.
-      serial_CM->set_action(ParCompactionManager::VerifyUpdate);
-      compact_perm(serial_CM);
-      compact_serial(serial_CM);
-      serial_CM->set_action(ParCompactionManager::ResetObjects);
-      compact_perm(serial_CM);
-      compact_serial(serial_CM);
-      serial_CM->set_action(ParCompactionManager::UpdateAndCopy);
+      vmthread_cm->set_action(ParCompactionManager::VerifyUpdate);
+      compact_perm(vmthread_cm);
+      compact_serial(vmthread_cm);
+      vmthread_cm->set_action(ParCompactionManager::ResetObjects);
+      compact_perm(vmthread_cm);
+      compact_serial(vmthread_cm);
+      vmthread_cm->set_action(ParCompactionManager::UpdateAndCopy);
 
       // For debugging only
       PSMarkSweep::restore_marks();
@@ -2084,16 +2085,14 @@
     compaction_start.update();
     // Does the perm gen always have to be done serially because
     // klasses are used in the update of an object?
-    compact_perm(serial_CM);
+    compact_perm(vmthread_cm);
 
     if (UseParallelOldGCCompacting) {
       compact();
     } else {
-      compact_serial(serial_CM);
+      compact_serial(vmthread_cm);
     }
 
-    delete serial_CM;
-
     // Reset the mark bitmap, summary data, and do other bookkeeping.  Must be
     // done before resizing.
     post_compact();

--- a/hotspot/src/share/vm/memory/cardTableModRefBS.cpp	Fri Jun 20 11:47:53 2008 -0700
+++ b/hotspot/src/share/vm/memory/cardTableModRefBS.cpp	Fri Jun 20 13:59:55 2008 -0700
@@ -196,6 +196,8 @@
   assert(_whole_heap.contains(new_region),
            "attempt to cover area not in reserved area");
   debug_only(verify_guard();)
+  // collided is true if the expansion would push into another committed region
+  debug_only(bool collided = false;)
   int const ind = find_covering_region_by_base(new_region.start());
   MemRegion const old_region = _covered[ind];
   assert(old_region.start() == new_region.start(), "just checking");
@@ -211,12 +213,36 @@
     }
     // Align the end up to a page size (starts are already aligned).
     jbyte* const new_end = byte_after(new_region.last());
-    HeapWord* const new_end_aligned =
+    HeapWord* new_end_aligned =
       (HeapWord*) align_size_up((uintptr_t)new_end, _page_size);
     assert(new_end_aligned >= (HeapWord*) new_end,
            "align up, but less");
+    int ri = 0;
+    for (ri = 0; ri < _cur_covered_regions; ri++) {
+      if (ri != ind) {
+        if (_committed[ri].contains(new_end_aligned)) {
+          assert((new_end_aligned >= _committed[ri].start()) &&
+                 (_committed[ri].start() > _committed[ind].start()),
+                 "New end of committed region is inconsistent");
+          new_end_aligned = _committed[ri].start();
+          assert(new_end_aligned > _committed[ind].start(),
+            "New end of committed region is before start");
+          debug_only(collided = true;)
+          // Should only collide with 1 region
+          break;
+        }
+      }
+    }
+#ifdef ASSERT
+    for (++ri; ri < _cur_covered_regions; ri++) {
+      assert(!_committed[ri].contains(new_end_aligned),
+        "New end of committed region is in a second committed region");
+    }
+#endif
     // The guard page is always committed and should not be committed over.
-    HeapWord* const new_end_for_commit = MIN2(new_end_aligned, _guard_region.start());
+    HeapWord* const new_end_for_commit = MIN2(new_end_aligned,
+                                              _guard_region.start());
+
     if (new_end_for_commit > cur_committed.end()) {
       // Must commit new pages.
       MemRegion const new_committed =
@@ -239,9 +265,11 @@
       if (!uncommit_region.is_empty()) {
         if (!os::uncommit_memory((char*)uncommit_region.start(),
                                  uncommit_region.byte_size())) {
-          // Do better than this for Merlin
-          vm_exit_out_of_memory(uncommit_region.byte_size(),
-            "card table contraction");
+          assert(false, "Card table contraction failed");
+          // The call failed so don't change the end of the
+          // committed region.  This is better than taking the
+          // VM down.
+          new_end_aligned = _committed[ind].end();
         }
       }
     }
@@ -257,8 +285,25 @@
     }
     assert(index_for(new_region.last()) < (int) _guard_index,
       "The guard card will be overwritten");
-    jbyte* const end = byte_after(new_region.last());
+    // This line commented out cleans the newly expanded region and
+    // not the aligned up expanded region.
+    // jbyte* const end = byte_after(new_region.last());
+    jbyte* const end = (jbyte*) new_end_for_commit;
+    assert((end >= byte_after(new_region.last())) || collided,
+      "Expect to be beyond new region unless impacting another region");
     // do nothing if we resized downward.
+#ifdef ASSERT
+    for (int ri = 0; ri < _cur_covered_regions; ri++) {
+      if (ri != ind) {
+        // The end of the new committed region should not
+        // be in any existing region unless it matches
+        // the start of the next region.
+        assert(!_committed[ri].contains(end) ||
+               (_committed[ri].start() == (HeapWord*) end),
+               "Overlapping committed regions");
+      }
+    }
+#endif
     if (entry < end) {
       memset(entry, clean_card, pointer_delta(end, entry, sizeof(jbyte)));
     }