Objects can no longer be migrated or evacuated into large object space

src/mark-compact.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2704 matching lines @@
 // to encounter pointers to dead new space objects during traversal of pointers
 // to new space.  We should clear them to avoid encountering them during next
 // pointer iteration.  This is an issue if the store buffer overflows and we
 // have to scan the entire old space, including dead objects, looking for
 // pointers to new space.
 void MarkCompactCollector::MigrateObject(Address dst,
                                          Address src,
                                          int size,
                                          AllocationSpace dest) {
   HEAP_PROFILE(heap(), ObjectMoveEvent(src, dst));
-  if (dest == OLD_POINTER_SPACE || dest == LO_SPACE) {
+  // TODO(hpayer): Replace that check with an assert.
+  CHECK(dest != LO_SPACE && size <= Page::kMaxNonCodeHeapObjectSize);
+  if (dest == OLD_POINTER_SPACE) {
     Address src_slot = src;
     Address dst_slot = dst;
     ASSERT(IsAligned(size, kPointerSize));
 
     for (int remaining = size / kPointerSize; remaining > 0; remaining--) {
       Object* value = Memory::Object_at(src_slot);
 
       Memory::Object_at(dst_slot) = value;
 
       if (heap_->InNewSpace(value)) {
@@ skipping 151 matching lines @@
   if (map_word.IsForwardingAddress()) {
     return String::cast(map_word.ToForwardingAddress());
   }
 
   return String::cast(*p);
 }
 
 
 bool MarkCompactCollector::TryPromoteObject(HeapObject* object,
                                             int object_size) {
+  // TODO(hpayer): Replace that check with an assert.
+  CHECK(object_size <= Page::kMaxNonCodeHeapObjectSize);
+
+  OldSpace* target_space = heap()->TargetSpace(object);
+
+  ASSERT(target_space == heap()->old_pointer_space() ||
+         target_space == heap()->old_data_space());
   Object* result;
-
-  if (object_size > Page::kMaxNonCodeHeapObjectSize) {
-    MaybeObject* maybe_result =
-        heap()->lo_space()->AllocateRaw(object_size, NOT_EXECUTABLE);
-    if (maybe_result->ToObject(&result)) {
-      HeapObject* target = HeapObject::cast(result);
-      MigrateObject(target->address(),
-                    object->address(),
-                    object_size,
-                    LO_SPACE);
-      heap()->mark_compact_collector()->tracer()->
-          increment_promoted_objects_size(object_size);
-      return true;
-    }
-  } else {
-    OldSpace* target_space = heap()->TargetSpace(object);
-
-    ASSERT(target_space == heap()->old_pointer_space() ||
-           target_space == heap()->old_data_space());
-    MaybeObject* maybe_result = target_space->AllocateRaw(object_size);
-    if (maybe_result->ToObject(&result)) {
-      HeapObject* target = HeapObject::cast(result);
-      MigrateObject(target->address(),
-                    object->address(),
-                    object_size,
-                    target_space->identity());
-      heap()->mark_compact_collector()->tracer()->
-          increment_promoted_objects_size(object_size);
-      return true;
-    }
+  MaybeObject* maybe_result = target_space->AllocateRaw(object_size);
+  if (maybe_result->ToObject(&result)) {
+    HeapObject* target = HeapObject::cast(result);
+    MigrateObject(target->address(),
+                  object->address(),
+                  object_size,
+                  target_space->identity());
+    heap()->mark_compact_collector()->tracer()->
+        increment_promoted_objects_size(object_size);
+    return true;
   }
 
   return false;
 }
 
 
 void MarkCompactCollector::EvacuateNewSpace() {
   // There are soft limits in the allocation code, designed trigger a mark
   // sweep collection by failing allocations.  But since we are already in
   // a mark-sweep allocation, there is no sense in trying to trigger one.
@@ skipping 1373 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 
 } }  // namespace v8::internal