Reland of "[heap] Divide available memory upon compaction tasks"

src/heap/mark-compact.cc

Index: src/heap/mark-compact.cc
diff --git a/src/heap/mark-compact.cc b/src/heap/mark-compact.cc
index 69cf62124570538157e38e7529c349666b89c57d..f64ed35be1b37b0938c2e6dc74f10aff2f755a08 100644
--- a/src/heap/mark-compact.cc
+++ b/src/heap/mark-compact.cc
@@ -566,9 +566,9 @@ void MarkCompactCollector::EnsureSweepingCompleted() {
 
   ParallelSweepSpacesComplete();
   sweeping_in_progress_ = false;
-  RefillFreeList(heap()->paged_space(OLD_SPACE));
-  RefillFreeList(heap()->paged_space(CODE_SPACE));
-  RefillFreeList(heap()->paged_space(MAP_SPACE));
+  heap()->old_space()->RefillFreeList();
+  heap()->code_space()->RefillFreeList();
+  heap()->map_space()->RefillFreeList();
 
 #ifdef VERIFY_HEAP
   if (FLAG_verify_heap && !evacuation()) {
@@ -588,26 +588,6 @@ bool MarkCompactCollector::IsSweepingCompleted() {
 }
 
 
-void MarkCompactCollector::RefillFreeList(PagedSpace* space) {
-  FreeList* free_list;
-
-  if (space == heap()->old_space()) {
-    free_list = free_list_old_space_.get();
-  } else if (space == heap()->code_space()) {
-    free_list = free_list_code_space_.get();
-  } else if (space == heap()->map_space()) {
-    free_list = free_list_map_space_.get();
-  } else {
-    // Any PagedSpace might invoke RefillFreeLists, so we need to make sure
-    // to only refill them for the old space.
-    return;
-  }
-
-  intptr_t added = space->free_list()->Concatenate(free_list);
-  space->accounting_stats_.IncreaseCapacity(added);
-}
-
-
 void Marking::TransferMark(Heap* heap, Address old_start, Address new_start) {
   // This is only used when resizing an object.
   DCHECK(MemoryChunk::FromAddress(old_start) ==
@@ -3435,11 +3415,10 @@ void MarkCompactCollector::EvacuatePagesInParallel() {
     compaction_spaces_for_tasks[i] = new CompactionSpaceCollection(heap());
   }
 
-  compaction_spaces_for_tasks[0]->Get(OLD_SPACE)->MoveOverFreeMemory(
-      heap()->old_space());
-  compaction_spaces_for_tasks[0]
-      ->Get(CODE_SPACE)
-      ->MoveOverFreeMemory(heap()->code_space());
+  heap()->old_space()->DivideUponCompactionSpaces(compaction_spaces_for_tasks,
+                                                  num_tasks);
+  heap()->code_space()->DivideUponCompactionSpaces(compaction_spaces_for_tasks,
+                                                   num_tasks);
 
   compaction_in_progress_ = true;
   // Kick off parallel tasks.
@@ -3451,9 +3430,7 @@ void MarkCompactCollector::EvacuatePagesInParallel() {
   }
 
   // Contribute in main thread. Counter and signal are in principal not needed.
-  concurrent_compaction_tasks_active_++;
   EvacuatePages(compaction_spaces_for_tasks[0], &migration_slots_buffer_);
-  pending_compaction_tasks_semaphore_.Signal();
 
   WaitUntilCompactionCompleted();