[heap] Exclude the owner of the linear allocation area from evacuation.

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 272 matching lines @@
     if (FLAG_compact_code_space) {
       CollectEvacuationCandidates(heap()->code_space());
     } else if (FLAG_trace_fragmentation) {
       TraceFragmentation(heap()->code_space());
     }
 
     if (FLAG_trace_fragmentation) {
       TraceFragmentation(heap()->map_space());
     }
 
-    heap()->old_space()->EvictEvacuationCandidatesFromLinearAllocationArea();
-    heap()->code_space()->EvictEvacuationCandidatesFromLinearAllocationArea();
-
     compacting_ = evacuation_candidates_.length() > 0;
   }
 
   return compacting_;
 }
 
 void MarkCompactCollector::CollectGarbage() {
   // Make sure that Prepare() has been called. The individual steps below will
   // update the state as they proceed.
   DCHECK(state_ == PREPARE_GC);
@@ skipping 328 matching lines @@
   size_t area_size = space->AreaSize();
 
   // Pairs of (live_bytes_in_page, page).
   typedef std::pair<size_t, Page*> LiveBytesPagePair;
   std::vector<LiveBytesPagePair> pages;
   pages.reserve(number_of_pages);
 
   DCHECK(!sweeping_in_progress());
   DCHECK(!FLAG_concurrent_sweeping ||
          sweeper().IsSweepingCompleted(space->identity()));
+  Page* owner_of_linear_allocation_area =
+      space->top() == space->limit()
+          ? nullptr
+          : Page::FromAllocationAreaAddress(space->top());
   for (Page* p : *space) {
-    if (p->NeverEvacuate()) continue;
+    if (p->NeverEvacuate() || p == owner_of_linear_allocation_area) continue;
     // Invariant: Evacuation candidates are just created when marking is
     // started. This means that sweeping has finished. Furthermore, at the end
     // of a GC all evacuation candidates are cleared and their slot buffers are
     // released.
     CHECK(!p->IsEvacuationCandidate());
     CHECK_NULL(p->old_to_old_slots());
     CHECK_NULL(p->typed_old_to_old_slots());
     CHECK(p->SweepingDone());
     DCHECK(p->area_size() == area_size);
     pages.push_back(std::make_pair(p->LiveBytesFromFreeList(), p));
@@ skipping 3259 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