On-the-fly bookkeeping of PagedSpace memory kept in free-lists.

src/mark-compact.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 654 matching lines @@
   if (!p->WasSwept()) {
     if (FLAG_trace_fragmentation) {
       PrintF("%p [%s]: %d bytes live (unswept)\n",
              reinterpret_cast<void*>(p),
              AllocationSpaceName(space->identity()),
              p->LiveBytes());
     }
     return 0;
   }
 
-  FreeList::SizeStats sizes;
-  space->CountFreeListItems(p, &sizes);
+  PagedSpace::SizeStats sizes;
+  space->ObtainFreeListStatistics(p, &sizes);
 
   intptr_t ratio;
   intptr_t ratio_threshold;
   intptr_t area_size = space->AreaSize();
   if (space->identity() == CODE_SPACE) {
     ratio = (sizes.medium_size_ * 10 + sizes.large_size_ * 2) * 100 /
         area_size;
     ratio_threshold = 10;
   } else {
     ratio = (sizes.small_size_ * 5 + sizes.medium_size_) * 100 /
@@ skipping 118 matching lines @@
       // Don't try to release too many pages.
       if (estimated_release >= ((over_reserved * 3) / 4)) {
         continue;
       }
 
       intptr_t free_bytes = 0;
 
       if (!p->WasSwept()) {
         free_bytes = (p->area_size() - p->LiveBytes());
       } else {
-        FreeList::SizeStats sizes;
-        space->CountFreeListItems(p, &sizes);
+        PagedSpace::SizeStats sizes;
+        space->ObtainFreeListStatistics(p, &sizes);
         free_bytes = sizes.Total();
       }
 
       int free_pct = static_cast<int>(free_bytes * 100) / p->area_size();
 
       if (free_pct >= kFreenessThreshold) {
         estimated_release += 2 * p->area_size() - free_bytes;
         fragmentation = free_pct;
       } else {
         fragmentation = 0;
@@ skipping 3306 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 
 } }  // namespace v8::internal