Revert "[heap] Attempt to incorporate backing store counters into heap sizing...

Revert "[heap] Attempt to incorporate backing store counters into heap sizing and GC trigger stragery."

This reverts commit ba735dde.

Reason for revert: https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8%20Linux64%20TSAN/21991

Original change's description:
> [heap] Attempt to incorporate backing store counters into heap sizing and GC trigger stragery.
> 
> Bug: chromium:845409
> Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
> Change-Id: Ic62a4339110e3dd2a6b1961a246e2bee0c07c03b
> Reviewed-on: https://chromium-review.googlesource.com/1160162
> Commit-Queue: Rodrigo Bruno <rfbpb@google.com>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#55128}

TBR=ulan@chromium.org,mlippautz@chromium.org,rfbpb@google.com

Change-Id: Iaf65227c65c11effa11662ac7d7bd7736f4d7846
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:845409
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/1174858Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55129}

include/v8.h

@@ -9486,7 +9486,7 @@ class Internals {
       kExternalMemoryLimitOffset + kApiInt64Size;
   static const int kIsolateRootsOffset = kExternalMemoryLimitOffset +
                                          kApiInt64Size + kApiInt64Size +
-                                         kApiInt64Size + kApiPointerSize;
+                                         kApiPointerSize + kApiPointerSize;
   static const int kUndefinedValueRootIndex = 4;
   static const int kTheHoleValueRootIndex = 5;
   static const int kNullValueRootIndex = 6;

src/api.cc

@@ -8693,8 +8693,7 @@ void Isolate::GetHeapStatistics(HeapStatistics* heap_statistics) {
   heap_statistics->malloced_memory_ =
       isolate->allocator()->GetCurrentMemoryUsage() +
       isolate->wasm_engine()->allocator()->GetCurrentMemoryUsage();
-  heap_statistics->external_memory_ = isolate->heap()->external_memory() +
-                                      isolate->heap()->backing_story_bytes();
+  heap_statistics->external_memory_ = isolate->heap()->external_memory();
   heap_statistics->peak_malloced_memory_ =
       isolate->allocator()->GetMaxMemoryUsage() +
       isolate->wasm_engine()->allocator()->GetMaxMemoryUsage();

src/heap/array-buffer-collector.cc

@@ -47,6 +47,8 @@ class ArrayBufferCollector::FreeingTask final : public CancelableTask {
 };
 
 void ArrayBufferCollector::FreeAllocationsOnBackgroundThread() {
+  // TODO(wez): Remove backing-store from external memory accounting.
+  heap_->account_external_memory_concurrently_freed();
   if (!heap_->IsTearingDown() && FLAG_concurrent_array_buffer_freeing) {
     V8::GetCurrentPlatform()->CallOnWorkerThread(
         base::make_unique<FreeingTask>(heap_));

src/heap/array-buffer-tracker-inl.h

@@ -30,6 +30,12 @@ void ArrayBufferTracker::RegisterNew(Heap* heap, JSArrayBuffer* buffer) {
     DCHECK_NOT_NULL(tracker);
     tracker->Add(buffer, length);
   }
+
+  // TODO(wez): Remove backing-store from external memory accounting.
+  // We may go over the limit of externally allocated memory here. We call the
+  // api function to trigger a GC in this case.
+  reinterpret_cast<v8::Isolate*>(heap->isolate())
+      ->AdjustAmountOfExternalAllocatedMemory(length);
 }
 
 void ArrayBufferTracker::Unregister(Heap* heap, JSArrayBuffer* buffer) {
@@ -43,6 +49,9 @@ void ArrayBufferTracker::Unregister(Heap* heap, JSArrayBuffer* buffer) {
     DCHECK_NOT_NULL(tracker);
     tracker->Remove(buffer, length);
   }
+
+  // TODO(wez): Remove backing-store from external memory accounting.
+  heap->update_external_memory(-static_cast<intptr_t>(length));
 }
 
 Space* LocalArrayBufferTracker::space() { return page_->owner(); }
@@ -67,6 +76,10 @@ void LocalArrayBufferTracker::Free(Callback should_free) {
   if (freed_memory > 0) {
     page_->DecrementExternalBackingStoreBytes(
         ExternalBackingStoreType::kArrayBuffer, freed_memory);
+
+    // TODO(wez): Remove backing-store from external memory accounting.
+    page_->heap()->update_external_memory_concurrently_freed(
+        static_cast<intptr_t>(freed_memory));
   }
 }
 
@@ -86,6 +99,7 @@ void ArrayBufferTracker::FreeDead(Page* page, MarkingState* marking_state) {
 void LocalArrayBufferTracker::Add(JSArrayBuffer* buffer, size_t length) {
   page_->IncrementExternalBackingStoreBytes(
       ExternalBackingStoreType::kArrayBuffer, length);
+
   auto ret = array_buffers_.insert(
       {buffer,
        {buffer->backing_store(), length, buffer->backing_store(),
@@ -99,6 +113,7 @@ void LocalArrayBufferTracker::Add(JSArrayBuffer* buffer, size_t length) {
 void LocalArrayBufferTracker::Remove(JSArrayBuffer* buffer, size_t length) {
   page_->DecrementExternalBackingStoreBytes(
       ExternalBackingStoreType::kArrayBuffer, length);
+
   TrackingData::iterator it = array_buffers_.find(buffer);
   // Check that we indeed find a key to remove.
   DCHECK(it != array_buffers_.end());

src/heap/array-buffer-tracker.cc

@@ -54,6 +54,7 @@ void LocalArrayBufferTracker::Process(Callback callback) {
         tracker->Add(new_buffer, size);
       }
       moved_memory += it->second.length;
+
     } else if (result == kRemoveEntry) {
       freed_memory += it->second.length;
       // We pass backing_store() and stored length to the collector for freeing
@@ -66,6 +67,11 @@ void LocalArrayBufferTracker::Process(Callback callback) {
       UNREACHABLE();
     }
   }
+  if (moved_memory || freed_memory) {
+    // TODO(wez): Remove backing-store from external memory accounting.
+    page_->heap()->update_external_memory_concurrently_freed(
+        static_cast<intptr_t>(freed_memory));
+  }
 
   array_buffers_.swap(kept_array_buffers);
 

src/heap/heap-controller.cc

@@ -66,10 +66,35 @@ double MemoryController::GrowingFactor(double gc_speed, double mutator_speed,
   return factor;
 }
 
+double MemoryController::MaxGrowingFactor(size_t curr_max_size) {
+  const double min_small_factor = 1.3;
+  const double max_small_factor = 2.0;
+  const double high_factor = 4.0;
+
+  size_t max_size_in_mb = curr_max_size / MB;
+  max_size_in_mb = Max(max_size_in_mb, kMinSize);
+
+  // If we are on a device with lots of memory, we allow a high heap
+  // growing factor.
+  if (max_size_in_mb >= kMaxSize) {
+    return high_factor;
+  }
+
+  DCHECK_GE(max_size_in_mb, kMinSize);
+  DCHECK_LT(max_size_in_mb, kMaxSize);
+
+  // On smaller devices we linearly scale the factor: (X-A)/(B-A)*(D-C)+C
+  double factor = (max_size_in_mb - kMinSize) *
+                      (max_small_factor - min_small_factor) /
+                      (kMaxSize - kMinSize) +
+                  min_small_factor;
+  return factor;
+}
+
 size_t MemoryController::CalculateAllocationLimit(
-    size_t curr_size, size_t max_size, double max_factor, double gc_speed,
-    double mutator_speed, size_t new_space_capacity,
-    Heap::HeapGrowingMode growing_mode) {
+    size_t curr_size, size_t max_size, double gc_speed, double mutator_speed,
+    size_t new_space_capacity, Heap::HeapGrowingMode growing_mode) {
+  double max_factor = MaxGrowingFactor(max_size);
   double factor = GrowingFactor(gc_speed, mutator_speed, max_factor);
 
   if (FLAG_trace_gc_verbose) {
@@ -100,7 +125,7 @@ size_t MemoryController::CalculateAllocationLimit(
                          MinimumAllocationLimitGrowingStep(growing_mode));
   limit += new_space_capacity;
   uint64_t halfway_to_the_max =
-      (static_cast<uint64_t>(curr_size) + static_cast<uint64_t>(max_size)) / 2;
+      (static_cast<uint64_t>(curr_size) + max_size) / 2;
   size_t result = static_cast<size_t>(Min(limit, halfway_to_the_max));
 
   if (FLAG_trace_gc_verbose) {
@@ -122,30 +147,5 @@ size_t MemoryController::MinimumAllocationLimitGrowingStep(
                       : kRegularAllocationLimitGrowingStep);
 }
 
-double HeapController::MaxGrowingFactor(size_t curr_max_size) {
-  const double min_small_factor = 1.3;
-  const double max_small_factor = 2.0;
-  const double high_factor = 4.0;
-
-  size_t max_size_in_mb = curr_max_size / MB;
-  max_size_in_mb = Max(max_size_in_mb, kMinSize);
-
-  // If we are on a device with lots of memory, we allow a high heap
-  // growing factor.
-  if (max_size_in_mb >= kMaxSize) {
-    return high_factor;
-  }
-
-  DCHECK_GE(max_size_in_mb, kMinSize);
-  DCHECK_LT(max_size_in_mb, kMaxSize);
-
-  // On smaller devices we linearly scale the factor: (X-A)/(B-A)*(D-C)+C
-  double factor = (max_size_in_mb - kMinSize) *
-                      (max_small_factor - min_small_factor) /
-                      (kMaxSize - kMinSize) +
-                  min_small_factor;
-  return factor;
-}
-
 }  // namespace internal
 }  // namespace v8

src/heap/heap-controller.h

@@ -18,18 +18,20 @@ class V8_EXPORT_PRIVATE MemoryController {
   MemoryController(Heap* heap, double min_growing_factor,
                    double max_growing_factor,
                    double conservative_growing_factor,
-                   double target_mutator_utilization)
+                   double target_mutator_utilization, size_t min_size,
+                   size_t max_size)
       : heap_(heap),
         kMinGrowingFactor(min_growing_factor),
         kMaxGrowingFactor(max_growing_factor),
         kConservativeGrowingFactor(conservative_growing_factor),
-        kTargetMutatorUtilization(target_mutator_utilization) {}
+        kTargetMutatorUtilization(target_mutator_utilization),
+        kMinSize(min_size),
+        kMaxSize(max_size) {}
   virtual ~MemoryController() {}
 
   // Computes the allocation limit to trigger the next garbage collection.
   size_t CalculateAllocationLimit(size_t curr_size, size_t max_size,
-                                  double max_factor, double gc_speed,
-                                  double mutator_speed,
+                                  double gc_speed, double mutator_speed,
                                   size_t new_space_capacity,
                                   Heap::HeapGrowingMode growing_mode);
 
@@ -39,6 +41,7 @@ class V8_EXPORT_PRIVATE MemoryController {
  protected:
   double GrowingFactor(double gc_speed, double mutator_speed,
                        double max_factor);
+  double MaxGrowingFactor(size_t curr_max_size);
   virtual const char* ControllerName() = 0;
 
   Heap* const heap_;
@@ -47,6 +50,9 @@ class V8_EXPORT_PRIVATE MemoryController {
   const double kMaxGrowingFactor;
   const double kConservativeGrowingFactor;
   const double kTargetMutatorUtilization;
+  // Sizes are in MB.
+  const size_t kMinSize;
+  const size_t kMaxSize;
 
   FRIEND_TEST(HeapControllerTest, HeapGrowingFactor);
   FRIEND_TEST(HeapControllerTest, MaxHeapGrowingFactor);
@@ -57,26 +63,17 @@ class V8_EXPORT_PRIVATE MemoryController {
 class HeapController : public MemoryController {
  public:
   explicit HeapController(Heap* heap)
-      : MemoryController(heap, 1.1, 4.0, 1.3, 0.97) {}
-  V8_EXPORT_PRIVATE double MaxGrowingFactor(size_t curr_max_size);
+      : MemoryController(heap, 1.1, 4.0, 1.3, 0.97, kMinHeapSize,
+                         kMaxHeapSize) {}
 
   // Sizes are in MB.
-  static const size_t kMinSize = 128 * Heap::kPointerMultiplier;
-  static const size_t kMaxSize = 1024 * Heap::kPointerMultiplier;
+  static const size_t kMinHeapSize = 128 * Heap::kPointerMultiplier;
+  static const size_t kMaxHeapSize = 1024 * Heap::kPointerMultiplier;
 
  protected:
   const char* ControllerName() { return "HeapController"; }
 };
 
-class GlobalMemoryController : public MemoryController {
- public:
-  explicit GlobalMemoryController(Heap* heap)
-      : MemoryController(heap, 1.1, 4.0, 1.3, 0.97) {}
-
- protected:
-  const char* ControllerName() { return "GlobalMemoryController"; }
-};
-
 }  // namespace internal
 }  // namespace v8
 

src/heap/heap.cc

@@ -138,7 +138,7 @@ Heap::Heap()
     : external_memory_(0),
       external_memory_limit_(kExternalAllocationSoftLimit),
       external_memory_at_last_mark_compact_(0),
-      backing_store_bytes_(0),
+      external_memory_concurrently_freed_(0),
       isolate_(nullptr),
       code_range_size_(0),
       // semispace_size_ should be a power of 2 and old_generation_size_ should
@@ -146,9 +146,6 @@ Heap::Heap()
       max_semi_space_size_(8 * (kPointerSize / 4) * MB),
       initial_semispace_size_(kMinSemiSpaceSizeInKB * KB),
       max_old_generation_size_(700ul * (kPointerSize / 4) * MB),
-      max_global_memory_size_(
-          Min(static_cast<uint64_t>(std::numeric_limits<size_t>::max()),
-              static_cast<uint64_t>(16) * GB)),
       initial_max_old_generation_size_(max_old_generation_size_),
       initial_old_generation_size_(max_old_generation_size_ /
                                    kInitalOldGenerationLimitFactor),
@@ -187,7 +184,6 @@ Heap::Heap()
       mmap_region_base_(0),
       remembered_unmapped_pages_index_(0),
       old_generation_allocation_limit_(initial_old_generation_size_),
-      global_memory_allocation_limit_(initial_old_generation_size_),
       inline_allocation_disabled_(false),
       tracer_(nullptr),
       promoted_objects_size_(0),
@@ -263,8 +259,8 @@ size_t Heap::ComputeMaxOldGenerationSize(uint64_t physical_memory) {
   size_t computed_size = static_cast<size_t>(physical_memory / i::MB /
                                              old_space_physical_memory_factor *
                                              kPointerMultiplier);
-  return Max(Min(computed_size, HeapController::kMaxSize),
-             HeapController::kMinSize);
+  return Max(Min(computed_size, HeapController::kMaxHeapSize),
+             HeapController::kMinHeapSize);
 }
 
 size_t Heap::Capacity() {
@@ -481,8 +477,6 @@ void Heap::PrintShortHeapStatistics() {
                CommittedMemoryOfHeapAndUnmapper() / KB);
   PrintIsolate(isolate_, "External memory reported: %6" PRId64 " KB\n",
                external_memory_ / KB);
-  PrintIsolate(isolate_, "Backing store memory reported: %6" PRId64 " KB\n",
-               backing_store_bytes_ / KB);
   PrintIsolate(isolate_, "External memory global %zu KB\n",
                external_memory_callback_() / KB);
   PrintIsolate(isolate_, "Total time spent in GC  : %.1f ms\n",
@@ -1469,11 +1463,8 @@ void Heap::StartIncrementalMarkingIfAllocationLimitIsReached(
     if (reached_limit == IncrementalMarkingLimit::kSoftLimit) {
       incremental_marking()->incremental_marking_job()->ScheduleTask(this);
     } else if (reached_limit == IncrementalMarkingLimit::kHardLimit) {
-      StartIncrementalMarking(
-          gc_flags,
-          OldGenerationSpaceAvailable() <= new_space_->Capacity()
-              ? GarbageCollectionReason::kAllocationLimit
-              : GarbageCollectionReason::kGlobalAllocationLimit,
+      StartIncrementalMarking(gc_flags,
+                              GarbageCollectionReason::kAllocationLimit,
                               gc_callback_flags);
     }
   }
@@ -1755,7 +1746,7 @@ bool Heap::PerformGarbageCollection(
   }
 
   UpdateSurvivalStatistics(static_cast<int>(start_new_space_size));
-  ConfigureInitialAllocationLimits();
+  ConfigureInitialOldGenerationSize();
 
   if (collector != MARK_COMPACTOR) {
     // Objects that died in the new space might have been accounted
@@ -1788,32 +1779,27 @@ bool Heap::PerformGarbageCollection(
   double gc_speed = tracer()->CombinedMarkCompactSpeedInBytesPerMillisecond();
   double mutator_speed =
       tracer()->CurrentOldGenerationAllocationThroughputInBytesPerMillisecond();
-  double max_factor =
-      heap_controller()->MaxGrowingFactor(max_old_generation_size_);
   size_t old_gen_size = OldGenerationSizeOfObjects();
-
-  size_t new_old_limit = heap_controller()->CalculateAllocationLimit(
-      old_gen_size, max_old_generation_size_, max_factor, gc_speed,
-      mutator_speed, new_space()->Capacity(), CurrentHeapGrowingMode());
-  size_t new_global_limit = global_controller()->CalculateAllocationLimit(
-      backing_store_bytes_ + old_gen_size, max_global_memory_size_, max_factor,
-      gc_speed, mutator_speed, new_space()->Capacity(),
-      CurrentHeapGrowingMode());
-
   if (collector == MARK_COMPACTOR) {
     // Register the amount of external allocated memory.
     external_memory_at_last_mark_compact_ = external_memory_;
     external_memory_limit_ = external_memory_ + kExternalAllocationSoftLimit;
 
-    set_allocation_limits(new_old_limit, new_global_limit);
+    size_t new_limit = heap_controller()->CalculateAllocationLimit(
+        old_gen_size, max_old_generation_size_, gc_speed, mutator_speed,
+        new_space()->Capacity(), CurrentHeapGrowingMode());
+    old_generation_allocation_limit_ = new_limit;
 
     CheckIneffectiveMarkCompact(
         old_gen_size, tracer()->AverageMarkCompactMutatorUtilization());
   } else if (HasLowYoungGenerationAllocationRate() &&
              old_generation_size_configured_) {
-    set_allocation_limits(
-        Min(old_generation_allocation_limit_, new_old_limit),
-        Min(global_memory_allocation_limit_, new_global_limit));
+    size_t new_limit = heap_controller()->CalculateAllocationLimit(
+        old_gen_size, max_old_generation_size_, gc_speed, mutator_speed,
+        new_space()->Capacity(), CurrentHeapGrowingMode());
+    if (new_limit < old_generation_allocation_limit_) {
+      old_generation_allocation_limit_ = new_limit;
+    }
   }
 
   {
@@ -2639,20 +2625,14 @@ void Heap::UnregisterArrayBuffer(JSArrayBuffer* buffer) {
   ArrayBufferTracker::Unregister(this, buffer);
 }
 
-size_t Heap::ConfigureInitialControllerSize(MemoryController* controller,
-                                            size_t curr_limit) {
-  return Max(
-      controller->MinimumAllocationLimitGrowingStep(CurrentHeapGrowingMode()),
-      static_cast<size_t>(static_cast<double>(curr_limit) *
-                          (tracer()->AverageSurvivalRatio() / 100)));
-}
-void Heap::ConfigureInitialAllocationLimits() {
+void Heap::ConfigureInitialOldGenerationSize() {
   if (!old_generation_size_configured_ && tracer()->SurvivalEventsRecorded()) {
-    size_t new_old_limit = ConfigureInitialControllerSize(
-        heap_controller_, old_generation_allocation_limit_);
-    size_t new_global_limit = ConfigureInitialControllerSize(
-        global_controller_, global_memory_allocation_limit_);
-    set_allocation_limits(new_old_limit, new_global_limit);
+    old_generation_allocation_limit_ =
+        Max(heap_controller()->MinimumAllocationLimitGrowingStep(
+                CurrentHeapGrowingMode()),
+            static_cast<size_t>(
+                static_cast<double>(old_generation_allocation_limit_) *
+                (tracer()->AverageSurvivalRatio() / 100)));
   }
 }
 
@@ -3602,8 +3582,8 @@ void Heap::CollectGarbageOnMemoryPressure() {
   double end = MonotonicallyIncreasingTimeInMs();
 
   // Estimate how much memory we can free.
-  int64_t potential_garbage = (CommittedMemory() - SizeOfObjects()) +
-                              external_memory_ + backing_store_bytes_;
+  int64_t potential_garbage =
+      (CommittedMemory() - SizeOfObjects()) + external_memory_;
   // If we can potentially free large amount of memory, then start GC right
   // away instead of waiting for memory reducer.
   if (potential_garbage >= kGarbageThresholdInBytes &&
@@ -3762,8 +3742,6 @@ const char* Heap::GarbageCollectionReasonToString(
       return "testing";
     case GarbageCollectionReason::kExternalFinalize:
       return "external finalize";
-    case GarbageCollectionReason::kGlobalAllocationLimit:
-      return "global allocation limit";
     case GarbageCollectionReason::kUnknown:
       return "unknown";
   }
@@ -4560,10 +4538,8 @@ Heap::IncrementalMarkingLimit Heap::IncrementalMarkingLimitReached() {
   }
 
   size_t old_generation_space_available = OldGenerationSpaceAvailable();
-  size_t global_available = GlobalMemorySpaceAvailable();
 
-  if (old_generation_space_available > new_space_->Capacity() &&
-      global_available > 0) {
+  if (old_generation_space_available > new_space_->Capacity()) {
     return IncrementalMarkingLimit::kNoLimit;
   }
   if (ShouldOptimizeForMemoryUsage()) {
@@ -4729,7 +4705,6 @@ void Heap::SetUp() {
   store_buffer_ = new StoreBuffer(this);
 
   heap_controller_ = new HeapController(this);
-  global_controller_ = new GlobalMemoryController(this);
 
   mark_compact_collector_ = new MarkCompactCollector(this);
   incremental_marking_ =
@@ -4973,11 +4948,6 @@ void Heap::TearDown() {
     heap_controller_ = nullptr;
   }
 
-  if (global_controller_ != nullptr) {
-    delete global_controller_;
-    global_controller_ = nullptr;
-  }
-
   if (mark_compact_collector_ != nullptr) {
     mark_compact_collector_->TearDown();
     delete mark_compact_collector_;

src/heap/heap.h

@@ -173,7 +173,6 @@ class GCIdleTimeHandler;
 class GCIdleTimeHeapState;
 class GCTracer;
 class HeapController;
-class GlobalMemoryController;
 class HeapObjectAllocationTracker;
 class HeapObjectsFilter;
 class HeapStats;
@@ -181,7 +180,6 @@ class HistogramTimer;
 class Isolate;
 class LocalEmbedderHeapTracer;
 class MemoryAllocator;
-class MemoryController;
 class MemoryReducer;
 class MinorMarkCompactCollector;
 class ObjectIterator;
@@ -237,8 +235,7 @@ enum class GarbageCollectionReason {
   kSamplingProfiler = 19,
   kSnapshotCreator = 20,
   kTesting = 21,
-  kExternalFinalize = 22,
-  kGlobalAllocationLimit = 23
+  kExternalFinalize = 22
   // If you add new items here, then update the incremental_marking_reason,
   // mark_compact_reason, and scavenge_reason counters in counters.h.
   // Also update src/tools/metrics/histograms/histograms.xml in chromium.
@@ -674,10 +671,15 @@ class Heap {
   int64_t external_memory_hard_limit() { return MaxOldGenerationSize() / 2; }
 
   int64_t external_memory() { return external_memory_; }
-  int64_t backing_story_bytes() const { return backing_store_bytes_; }
+  void update_external_memory(int64_t delta) { external_memory_ += delta; }
 
-  void update_backing_store_bytes(int64_t amount) {
-    backing_store_bytes_ += amount;
+  void update_external_memory_concurrently_freed(intptr_t freed) {
+    external_memory_concurrently_freed_ += freed;
+  }
+
+  void account_external_memory_concurrently_freed() {
+    external_memory_ -= external_memory_concurrently_freed_;
+    external_memory_concurrently_freed_ = 0;
   }
 
   void ProcessMovedExternalString(Page* old_page, Page* new_page,
@@ -1689,9 +1691,7 @@ class Heap {
   // Flush the number to string cache.
   void FlushNumberStringCache();
 
-  size_t ConfigureInitialControllerSize(MemoryController* controller,
-                                        size_t curr_limit);
-  void ConfigureInitialAllocationLimits();
+  void ConfigureInitialOldGenerationSize();
 
   bool HasLowYoungGenerationAllocationRate();
   bool HasLowOldGenerationAllocationRate();
@@ -1806,13 +1806,6 @@ class Heap {
                OldGenerationObjectsAndPromotedExternalMemorySize());
   }
 
-  inline size_t GlobalMemorySpaceAvailable() {
-    size_t global_used = OldGenerationSizeOfObjects() + backing_store_bytes_;
-    return global_used > global_memory_allocation_limit_
-               ? 0
-               : global_memory_allocation_limit_ - global_used;
-  }
-
   // We allow incremental marking to overshoot the allocation limit for
   // performace reasons. If the overshoot is too large then we are more
   // eager to finalize incremental marking.
@@ -1847,7 +1840,6 @@ class Heap {
   // ===========================================================================
 
   HeapController* heap_controller() { return heap_controller_; }
-  GlobalMemoryController* global_controller() { return global_controller_; }
   MemoryReducer* memory_reducer() { return memory_reducer_; }
 
   // For some webpages RAIL mode does not switch from PERFORMANCE_LOAD.
@@ -1858,12 +1850,6 @@ class Heap {
 
   bool ShouldOptimizeForLoadTime();
 
-  void set_allocation_limits(size_t old_generation_allocation_limit,
-                             size_t global_memory_allocation_limit) {
-    old_generation_allocation_limit_ = old_generation_allocation_limit;
-    global_memory_allocation_limit_ = global_memory_allocation_limit;
-  }
-
   size_t old_generation_allocation_limit() const {
     return old_generation_allocation_limit_;
   }
@@ -1978,8 +1964,8 @@ class Heap {
   // Caches the amount of external memory registered at the last MC.
   int64_t external_memory_at_last_mark_compact_;
 
-  // Backing store bytes (array buffers and external strings).
-  std::atomic<int64_t> backing_store_bytes_;
+  // The amount of memory that has been freed concurrently.
+  std::atomic<intptr_t> external_memory_concurrently_freed_;
 
   // This can be calculated directly from a pointer to the heap; however, it is
   // more expedient to get at the isolate directly from within Heap methods.
@@ -2012,7 +1998,6 @@ class Heap {
   size_t max_semi_space_size_;
   size_t initial_semispace_size_;
   size_t max_old_generation_size_;
-  size_t max_global_memory_size_;
   size_t initial_max_old_generation_size_;
   size_t initial_old_generation_size_;
   bool old_generation_size_configured_;
@@ -2113,10 +2098,6 @@ class Heap {
   // generation and on every allocation in large object space.
   size_t old_generation_allocation_limit_;
 
-  // The limit when to trigger memory pressure. This limit accounts for JS
-  // memory and external memory (array buffers and external strings).
-  size_t global_memory_allocation_limit_;
-
   // Indicates that inline bump-pointer allocation has been globally disabled
   // for all spaces. This is used to disable allocations in generated code.
   bool inline_allocation_disabled_;
@@ -2170,7 +2151,6 @@ class Heap {
   StoreBuffer* store_buffer_;
 
   HeapController* heap_controller_;
-  GlobalMemoryController* global_controller_;
 
   IncrementalMarking* incremental_marking_;
   ConcurrentMarking* concurrent_marking_;

src/heap/mark-compact.cc

@@ -803,6 +803,7 @@ void MarkCompactCollector::Prepare() {
        space = spaces.next()) {
     space->PrepareForMarkCompact();
   }
+  heap()->account_external_memory_concurrently_freed();
 
 #ifdef VERIFY_HEAP
   if (!was_marked_incrementally_ && FLAG_verify_heap) {
@@ -3848,6 +3849,8 @@ void MinorMarkCompactCollector::CollectGarbage() {
           RememberedSet<OLD_TO_NEW>::PreFreeEmptyBuckets(chunk);
         }
       });
+
+  heap()->account_external_memory_concurrently_freed();
 }
 
 void MinorMarkCompactCollector::MakeIterable(

src/heap/spaces.h

@@ -1003,13 +1003,11 @@ class Space : public Malloced {
   void IncrementExternalBackingStoreBytes(ExternalBackingStoreType type,
                                           size_t amount) {
     external_backing_store_bytes_[type] += amount;
-    heap()->update_backing_store_bytes(static_cast<int64_t>(amount));
   }
   void DecrementExternalBackingStoreBytes(ExternalBackingStoreType type,
                                           size_t amount) {
     DCHECK_GE(external_backing_store_bytes_[type], amount);
     external_backing_store_bytes_[type] -= amount;
-    heap()->update_backing_store_bytes(-static_cast<int64_t>(amount));
   }
 
   V8_EXPORT_PRIVATE void* GetRandomMmapAddr();

test/unittests/heap/heap-controller-unittest.cc

@@ -51,14 +51,15 @@ TEST_F(HeapControllerTest, HeapGrowingFactor) {
 TEST_F(HeapControllerTest, MaxHeapGrowingFactor) {
   HeapController heap_controller(i_isolate()->heap());
   CheckEqualRounded(
-      1.3, heap_controller.MaxGrowingFactor(HeapController::kMinSize * MB));
+      1.3, heap_controller.MaxGrowingFactor(heap_controller.kMinSize * MB));
   CheckEqualRounded(1.600, heap_controller.MaxGrowingFactor(
-                               HeapController::kMaxSize / 2 * MB));
+                               heap_controller.kMaxSize / 2 * MB));
   CheckEqualRounded(
       1.999, heap_controller.MaxGrowingFactor(
-                 (HeapController::kMaxSize - Heap::kPointerMultiplier) * MB));
-  CheckEqualRounded(
-      4.0, heap_controller.MaxGrowingFactor(HeapController::kMaxSize * MB));
+                 (heap_controller.kMaxSize - Heap::kPointerMultiplier) * MB));
+  CheckEqualRounded(4.0,
+                    heap_controller.MaxGrowingFactor(
+                        static_cast<size_t>(heap_controller.kMaxSize) * MB));
 }
 
 TEST_F(HeapControllerTest, OldGenerationAllocationLimit) {
@@ -74,43 +75,39 @@ TEST_F(HeapControllerTest, OldGenerationAllocationLimit) {
   double factor =
       heap_controller.GrowingFactor(gc_speed, mutator_speed, max_factor);
 
-  EXPECT_EQ(
-      static_cast<size_t>(old_gen_size * factor + new_space_capacity),
+  EXPECT_EQ(static_cast<size_t>(old_gen_size * factor + new_space_capacity),
             heap->heap_controller()->CalculateAllocationLimit(
-          old_gen_size, max_old_generation_size, max_factor, gc_speed,
-          mutator_speed, new_space_capacity, Heap::HeapGrowingMode::kDefault));
+                old_gen_size, max_old_generation_size, gc_speed, mutator_speed,
+                new_space_capacity, Heap::HeapGrowingMode::kDefault));
 
   factor = Min(factor, heap_controller.kConservativeGrowingFactor);
-  EXPECT_EQ(
-      static_cast<size_t>(old_gen_size * factor + new_space_capacity),
+  EXPECT_EQ(static_cast<size_t>(old_gen_size * factor + new_space_capacity),
             heap->heap_controller()->CalculateAllocationLimit(
-          old_gen_size, max_old_generation_size, max_factor, gc_speed,
-          mutator_speed, new_space_capacity, Heap::HeapGrowingMode::kSlow));
+                old_gen_size, max_old_generation_size, gc_speed, mutator_speed,
+                new_space_capacity, Heap::HeapGrowingMode::kSlow));
 
   factor = Min(factor, heap_controller.kConservativeGrowingFactor);
   EXPECT_EQ(static_cast<size_t>(old_gen_size * factor + new_space_capacity),
             heap->heap_controller()->CalculateAllocationLimit(
-                old_gen_size, max_old_generation_size, max_factor, gc_speed,
-                mutator_speed, new_space_capacity,
-                Heap::HeapGrowingMode::kConservative));
+                old_gen_size, max_old_generation_size, gc_speed, mutator_speed,
+                new_space_capacity, Heap::HeapGrowingMode::kConservative));
 
   factor = heap_controller.kMinGrowingFactor;
-  EXPECT_EQ(
-      static_cast<size_t>(old_gen_size * factor + new_space_capacity),
+  EXPECT_EQ(static_cast<size_t>(old_gen_size * factor + new_space_capacity),
             heap->heap_controller()->CalculateAllocationLimit(
-          old_gen_size, max_old_generation_size, max_factor, gc_speed,
-          mutator_speed, new_space_capacity, Heap::HeapGrowingMode::kMinimal));
+                old_gen_size, max_old_generation_size, gc_speed, mutator_speed,
+                new_space_capacity, Heap::HeapGrowingMode::kMinimal));
 }
 
 TEST_F(HeapControllerTest, MaxOldGenerationSize) {
   HeapController heap_controller(i_isolate()->heap());
   uint64_t configurations[][2] = {
-      {0, HeapController::kMinSize},
-      {512, HeapController::kMinSize},
+      {0, heap_controller.kMinSize},
+      {512, heap_controller.kMinSize},
       {1 * GB, 256 * Heap::kPointerMultiplier},
       {2 * static_cast<uint64_t>(GB), 512 * Heap::kPointerMultiplier},
-      {4 * static_cast<uint64_t>(GB), HeapController::kMaxSize},
-      {8 * static_cast<uint64_t>(GB), HeapController::kMaxSize}};
+      {4 * static_cast<uint64_t>(GB), heap_controller.kMaxSize},
+      {8 * static_cast<uint64_t>(GB), heap_controller.kMaxSize}};
 
   for (auto configuration : configurations) {
     ASSERT_EQ(configuration[1],