[heap] Remove border page

src/heap/mark-compact.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/heap/mark-compact.h"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/base/sys-info.h"
 #include "src/code-stubs.h"
@@ skipping 3170 matching lines @@
         }
         break;
       default:
         UNREACHABLE();
     }
   }
   ReportCompactionProgress(evacuation_time, saved_live_bytes);
   if (FLAG_trace_evacuation) {
     PrintIsolate(heap->isolate(),
                  "evacuation[%p]: page=%p new_space=%d "
-                 "page_evacuation=%d executable=%d contains_age_mark=%d "
-                 "live_bytes=%d time=%f\n",
+                 "page_evacuation=%d executable=%d live_bytes=%d time=%f\n",
                  static_cast<void*>(this), static_cast<void*>(page),
                  page->InNewSpace(),
                  page->IsFlagSet(Page::PAGE_NEW_OLD_PROMOTION) ||
                      page->IsFlagSet(Page::PAGE_NEW_NEW_PROMOTION),
-                 page->IsFlagSet(MemoryChunk::IS_EXECUTABLE),
-                 page->Contains(heap->new_space()->age_mark()),
-                 saved_live_bytes, evacuation_time);
+                 page->IsFlagSet(MemoryChunk::IS_EXECUTABLE), saved_live_bytes,
+                 evacuation_time);
   }
   return success;
 }
 
 void MarkCompactCollector::Evacuator::Finalize() {
   heap()->old_space()->MergeCompactionSpace(compaction_spaces_.Get(OLD_SPACE));
   heap()->code_space()->MergeCompactionSpace(
       compaction_spaces_.Get(CODE_SPACE));
   heap()->tracer()->AddCompactionEvent(duration_, bytes_compacted_);
   heap()->IncrementPromotedObjectsSize(new_space_visitor_.promoted_size() +
@@ skipping 89 matching lines @@
       heap_, heap_->isolate()->cancelable_task_manager(),
       &page_parallel_job_semaphore_);
 
   int abandoned_pages = 0;
   intptr_t live_bytes = 0;
   for (Page* page : evacuation_candidates_) {
     live_bytes += page->LiveBytes();
     job.AddPage(page, &abandoned_pages);
   }
 
-  const Address age_mark = heap()->new_space()->age_mark();
   for (Page* page : newspace_evacuation_candidates_) {
     live_bytes += page->LiveBytes();
     if (!page->NeverEvacuate() &&
-        (page->LiveBytes() > Evacuator::PageEvacuationThreshold()) &&
-        !page->Contains(age_mark)) {
-      if (page->IsFlagSet(MemoryChunk::NEW_SPACE_BELOW_AGE_MARK)) {
+        (page->LiveBytes() > Evacuator::PageEvacuationThreshold())) {
+      if (page->InIntermediateGeneration()) {
         EvacuateNewSpacePageVisitor::MoveToOldSpace(page, heap()->old_space());
       } else {
         EvacuateNewSpacePageVisitor::MoveToToSpace(page);
       }
     }
 
     job.AddPage(page, &abandoned_pages);
   }
   DCHECK_GE(job.NumberOfPages(), 1);
 
@@ skipping 225 matching lines @@
 void MarkCompactCollector::EvacuateNewSpaceAndCandidates() {
   TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_EVACUATE);
   Heap::RelocationLock relocation_lock(heap());
 
   {
     TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_EVACUATE_COPY);
     EvacuationScope evacuation_scope(this);
 
     EvacuateNewSpacePrologue();
     EvacuatePagesInParallel();
-    heap()->new_space()->set_age_mark(heap()->new_space()->top());
+    heap()->new_space()->SealIntermediateGeneration();
   }
 
   UpdatePointersAfterEvacuation();
 
   if (!heap()->new_space()->Rebalance()) {
     FatalProcessOutOfMemory("NewSpace::Rebalance");
   }
 
   // Give pages that are queued to be freed back to the OS. Note that filtering
   // slots only handles old space (for unboxed doubles), and thus map space can
@@ skipping 470 matching lines @@
       // The target is always in old space, we don't have to record the slot in
       // the old-to-new remembered set.
       DCHECK(!heap()->InNewSpace(target));
       RecordRelocSlot(host, &rinfo, target);
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8