Never uncommit the whole marking deque in case we can't get it back

src/heap/heap.cc

 // Copyright 2012 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/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 1215 matching lines @@
 
   // This should be updated before PostGarbageCollectionProcessing, which can
   // cause another GC.
   old_generation_size_at_last_gc_ = PromotedSpaceSizeOfObjects();
 
   UpdateSurvivalStatistics(start_new_space_size);
   ConfigureInitialOldGenerationSize();
 
   isolate_->counters()->objs_since_last_young()->Set(0);
 
-  // Callbacks that fire after this point might trigger nested GCs and
-  // restart incremental marking, the assertion can't be moved down.
-  DCHECK(collector == SCAVENGER || incremental_marking()->IsStopped());
+  if (collector != SCAVENGER) {
+    // Callbacks that fire after this point might trigger nested GCs and
+    // restart incremental marking, the assertion can't be moved down.
+    DCHECK(incremental_marking()->IsStopped());
+
+    // We finished a marking cycle. We can uncommit the marking deque until
+    // we start marking again.
+    mark_compact_collector_.marking_deque()->Uninitialize();
+    mark_compact_collector_.EnsureMarkingDequeIsCommitted(
+        MarkCompactCollector::kMinMarkingDequeSize);
+  }
 
   gc_post_processing_depth_++;
   {
     AllowHeapAllocation allow_allocation;
     GCTracer::Scope scope(tracer(), GCTracer::Scope::EXTERNAL);
     freed_global_handles =
         isolate_->global_handles()->PostGarbageCollectionProcessing(collector);
   }
   gc_post_processing_depth_--;
 
   isolate_->eternal_handles()->PostGarbageCollectionProcessing(this);
 
   // Update relocatables.
   Relocatable::PostGarbageCollectionProcessing(isolate_);
 
   if (collector == MARK_COMPACTOR) {
     // Register the amount of external allocated memory.
     amount_of_external_allocated_memory_at_last_global_gc_ =
         amount_of_external_allocated_memory_;
     SetOldGenerationAllocationLimit(
         PromotedSpaceSizeOfObjects(),
         tracer()->CurrentAllocationThroughputInBytesPerMillisecond());
-    // We finished a marking cycle. We can uncommit the marking deque until
-    // we start marking again.
-    mark_compact_collector_.UncommitMarkingDeque();
   }
 
   {
     GCCallbacksScope scope(this);
     if (scope.CheckReenter()) {
       AllowHeapAllocation allow_allocation;
       GCTracer::Scope scope(tracer(), GCTracer::Scope::EXTERNAL);
       VMState<EXTERNAL> state(isolate_);
       HandleScope handle_scope(isolate_);
       CallGCEpilogueCallbacks(gc_type, gc_callback_flags);
@@ skipping 5294 matching lines @@
     *object_type = "CODE_TYPE";                                                \
     *object_sub_type = "CODE_AGE/" #name;                                      \
     return true;
     CODE_AGE_LIST_COMPLETE(COMPARE_AND_RETURN_NAME)
 #undef COMPARE_AND_RETURN_NAME
   }
   return false;
 }
 }  // namespace internal
 }  // namespace v8