[heap] Tenure large objects based on size (currently 32K).

Bug: chromium:852420
Change-Id: Ibb8cd735036368c5bda83fe60b12b427e8e7ce7f
Reviewed-on: https://chromium-review.googlesource.com/1127887Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Hannes Payer <hpayer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54296}

src/globals.h

@@ -251,6 +251,10 @@ constexpr int kExternalAllocationSoftLimit = 64 * MB;
 // Current value: Page::kAllocatableMemory (on 32-bit arch) - 512 (slack).
 constexpr int kMaxRegularHeapObjectSize = 507136;
 
+// Objects smaller or equal kMaxNewSpaceHeapObjectSize are allocated in the
+// new large object space.
+constexpr int kMaxNewSpaceHeapObjectSize = 32 * KB;
+
 STATIC_ASSERT(kPointerSize == (1 << kPointerSizeLog2));
 
 constexpr int kBitsPerByte = 8;

src/heap/heap-inl.h

@@ -154,13 +154,19 @@ AllocationResult Heap::AllocateRaw(int size_in_bytes, AllocationSpace space,
 #endif
 
   bool large_object = size_in_bytes > kMaxRegularHeapObjectSize;
+  bool new_large_object = FLAG_young_generation_large_objects &&
+                          size_in_bytes > kMaxNewSpaceHeapObjectSize;
   HeapObject* object = nullptr;
   AllocationResult allocation;
   if (NEW_SPACE == space) {
     if (large_object) {
       space = LO_SPACE;
     } else {
-      allocation = new_space_->AllocateRaw(size_in_bytes, alignment);
+      if (new_large_object) {
+        allocation = new_lo_space_->AllocateRaw(size_in_bytes);
+      } else {
+        allocation = new_space_->AllocateRaw(size_in_bytes, alignment);
+      }
       if (allocation.To(&object)) {
         OnAllocationEvent(object, size_in_bytes);
       }
@@ -183,11 +189,7 @@ AllocationResult Heap::AllocateRaw(int size_in_bytes, AllocationSpace space,
     }
   } else if (LO_SPACE == space) {
     DCHECK(large_object);
-    if (FLAG_young_generation_large_objects) {
-      allocation = new_lo_space_->AllocateRaw(size_in_bytes);
-    } else {
-      allocation = lo_space_->AllocateRaw(size_in_bytes, NOT_EXECUTABLE);
-    }
+    allocation = lo_space_->AllocateRaw(size_in_bytes, NOT_EXECUTABLE);
   } else if (MAP_SPACE == space) {
     allocation = map_space_->AllocateRawUnaligned(size_in_bytes);
   } else if (RO_SPACE == space) {

test/cctest/heap/test-heap.cc

@@ -5670,6 +5670,11 @@ TEST(YoungGenerationLargeObjectAllocation) {
 
   Handle<FixedArray> array = isolate->factory()->NewFixedArray(200000);
   MemoryChunk* chunk = MemoryChunk::FromAddress(array->address());
+  CHECK(chunk->owner()->identity() == LO_SPACE);
+  CHECK(!chunk->IsFlagSet(MemoryChunk::IN_TO_SPACE));
+
+  Handle<FixedArray> array_small = isolate->factory()->NewFixedArray(20000);
+  chunk = MemoryChunk::FromAddress(array_small->address());
   CHECK(chunk->owner()->identity() == NEW_LO_SPACE);
   CHECK(chunk->IsFlagSet(MemoryChunk::IN_TO_SPACE));
 }