[heap] Evacuation for young generation

test/cctest/heap/test-page-promotion.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/factory.h"
 #include "src/heap/array-buffer-tracker.h"
 #include "src/heap/spaces-inl.h"
 #include "src/isolate.h"
 // FIXME(mstarzinger, marja): This is weird, but required because of the missing
 // (disallowed) include: src/factory.h -> src/objects-inl.h
 #include "src/objects-inl.h"
 // FIXME(mstarzinger, marja): This is weird, but required because of the missing
 // (disallowed) include: src/feedback-vector.h ->
 // src/feedback-vector-inl.h
 #include "src/feedback-vector-inl.h"
 #include "test/cctest/cctest.h"
 #include "test/cctest/heap/heap-tester.h"
 #include "test/cctest/heap/heap-utils.h"
 
 namespace {
 
 v8::Isolate* NewIsolateForPagePromotion(int min_semi_space_size = 8,
                                         int max_semi_space_size = 8) {
+  // Parallel evacuation messes with fragmentation in a way that objects that
+  // should be copied in semi space are promoted to old space because of
+  // fragmentation.
+  i::FLAG_parallel_compaction = false;
   i::FLAG_page_promotion = true;
   i::FLAG_page_promotion_threshold = 0;  // %
   i::FLAG_min_semi_space_size = min_semi_space_size;
   // We cannot optimize for size as we require a new space with more than one
   // page.
   i::FLAG_optimize_for_size = false;
   // Set max_semi_space_size because it could've been initialized by an
   // implication of optimize_for_size.
   i::FLAG_max_semi_space_size = max_semi_space_size;
   v8::Isolate::CreateParams create_params;
@@ skipping 145 matching lines @@
     heap->CollectGarbage(NEW_SPACE, i::GarbageCollectionReason::kTesting);
     heap->new_space()->Shrink();
     heap->memory_allocator()->unmapper()->WaitUntilCompleted();
     heap->mark_compact_collector()->sweeper().StartSweeperTasks();
     heap->mark_compact_collector()->EnsureSweepingCompleted();
   }
 }
 
 }  // namespace internal
 }  // namespace v8