Revert "[heap] Release dead young generation large objects in the Scavenger."

This reverts commit 40b448ea.

Reason for revert: https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8%20Win64/27711

Original change's description:
> [heap] Release dead young generation large objects in the Scavenger.
> 
> Bug: chromium:852420
> Change-Id: Ieefbee7bfd625d62e9104950bdfa8e46d5f4270a
> Reviewed-on: https://chromium-review.googlesource.com/c/1348081
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Commit-Queue: Hannes Payer <hpayer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#57761}

TBR=ulan@chromium.org,hpayer@chromium.org

Change-Id: I6b57dd8ed92d85b5ce012da754611278ceaefe20
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:852420
Reviewed-on: https://chromium-review.googlesource.com/c/1349270Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57763}

src/heap/scavenger.cc

@@ -269,11 +269,6 @@ void ScavengerCollector::CollectGarbage() {
   }
   heap_->array_buffer_collector()->FreeAllocations();
 
-  // Since we promote all surviving large objects immediatelly, all remaining
-  // large objects must be dead.
-  // TODO(hpayer): Don't free all as soon as we have an intermediate generation.
-  heap_->new_lo_space()->FreeAllObjects();
-
   RememberedSet<OLD_TO_NEW>::IterateMemoryChunks(heap_, [](MemoryChunk* chunk) {
     if (chunk->SweepingDone()) {
       RememberedSet<OLD_TO_NEW>::FreeEmptyBuckets(chunk);
@@ -301,6 +296,7 @@ void ScavengerCollector::HandleSurvivingNewLargeObjects() {
     LargePage* page = LargePage::FromHeapObject(object);
     heap_->lo_space()->PromoteNewLargeObject(page);
   }
+  DCHECK(heap_->new_lo_space()->IsEmpty());
 }
 
 void ScavengerCollector::MergeSurvivingNewLargeObjects(

src/heap/spaces.cc

@@ -3749,19 +3749,6 @@ void NewLargeObjectSpace::Flip() {
   }
 }
 
-void NewLargeObjectSpace::FreeAllObjects() {
-  LargePage* current = first_page();
-  objects_size_ = 0;
-  while (current) {
-    LargePage* next_current = current->next_page();
-    Unregister(current, static_cast<size_t>(current->GetObject()->Size()));
-    heap()->memory_allocator()->Free<MemoryAllocator::kPreFreeAndQueue>(
-        current);
-    current = next_current;
-  }
-  DCHECK_EQ(objects_size_, 0);
-}
-
 CodeLargeObjectSpace::CodeLargeObjectSpace(Heap* heap)
     : LargeObjectSpace(heap, CODE_LO_SPACE) {}
 

src/heap/spaces.h

@@ -3038,11 +3038,11 @@ class LargeObjectSpace : public Space {
   V8_WARN_UNUSED_RESULT AllocationResult AllocateRaw(int object_size,
                                                      Executability executable);
 
+ private:
   size_t size_;          // allocated bytes
   int page_count_;       // number of chunks
   size_t objects_size_;  // size of objects
 
- private:
   // The chunk_map_mutex_ has to be used when the chunk map is accessed
   // concurrently.
   base::Mutex chunk_map_mutex_;
@@ -3063,8 +3063,6 @@ class NewLargeObjectSpace : public LargeObjectSpace {
   size_t Available() override;
 
   void Flip();
-
-  void FreeAllObjects();
 };
 
 class CodeLargeObjectSpace : public LargeObjectSpace {

test/cctest/heap/test-heap.cc

@@ -5791,34 +5791,6 @@ TEST(YoungGenerationLargeObjectAllocationMarkCompact) {
   CcTest::CollectAllAvailableGarbage();
 }
 
-TEST(YoungGenerationLargeObjectAllocationReleaseScavenger) {
-  if (FLAG_minor_mc) return;
-  FLAG_young_generation_large_objects = true;
-  CcTest::InitializeVM();
-  v8::HandleScope scope(CcTest::isolate());
-  Heap* heap = CcTest::heap();
-  Isolate* isolate = heap->isolate();
-  if (!isolate->serializer_enabled()) return;
-
-  {
-    HandleScope scope(isolate);
-    for (int i = 0; i < 10; i++) {
-      Handle<FixedArray> array_small = isolate->factory()->NewFixedArray(20000);
-      MemoryChunk* chunk = MemoryChunk::FromAddress(array_small->address());
-      CHECK_EQ(NEW_LO_SPACE, chunk->owner()->identity());
-      CHECK(chunk->IsFlagSet(MemoryChunk::IN_TO_SPACE));
-    }
-  }
-
-  CcTest::CollectGarbage(NEW_SPACE);
-  CHECK(isolate->heap()->new_lo_space()->IsEmpty());
-  CHECK_EQ(0, isolate->heap()->new_lo_space()->Size());
-  CHECK_EQ(0, isolate->heap()->new_lo_space()->SizeOfObjects());
-  CHECK(isolate->heap()->lo_space()->IsEmpty());
-  CHECK_EQ(0, isolate->heap()->lo_space()->Size());
-  CHECK_EQ(0, isolate->heap()->lo_space()->SizeOfObjects());
-}
-
 TEST(UncommitUnusedLargeObjectMemory) {
   CcTest::InitializeVM();
   v8::HandleScope scope(CcTest::isolate());