Added a special stack guard to deopt marked allocation sites.

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index c17794f99b394456583b5bf9d9241777f1bc0d63..cd202e390e5a9aa1bd3d52b15c8637b4520fddfe 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -545,7 +545,9 @@ void Heap::ProcessPretenuringFeedback() {
       }
     }
 
-    if (trigger_deoptimization) isolate_->stack_guard()->DeoptMarkedCode();
+    if (trigger_deoptimization) {
+      isolate_->stack_guard()->DeoptMarkedAllocationSites();
+    }
 
     FlushAllocationSitesScratchpad();
 
@@ -567,6 +569,25 @@ void Heap::ProcessPretenuringFeedback() {
 }
 
 
+void Heap::DeoptMarkedAllocationSites() {
+  // TODO(hpayer): If iterating over the allocation sites list becomes a
+  // performance issue, use a cache heap data structure instead (similar to the
+  // allocation sites scratchpad).
+  Object* list_element = allocation_sites_list();
+  while (list_element->IsAllocationSite()) {
+    AllocationSite* site = AllocationSite::cast(list_element);
+    if (site->deopt_dependent_code()) {
+      site->dependent_code()->MarkCodeForDeoptimization(
+          isolate_,
+          DependentCode::kAllocationSiteTenuringChangedGroup);
+      site->set_deopt_dependent_code(false);
+    }
+    list_element = site->weak_next();
+  }
+  Deoptimizer::DeoptimizeMarkedCode(isolate_);
+}
+
+
 void Heap::GarbageCollectionEpilogue() {
   store_buffer()->GCEpilogue();
 
@@ -2000,14 +2021,12 @@ void Heap::ResetAllAllocationSitesDependentCode(PretenureFlag flag) {
     AllocationSite* casted = AllocationSite::cast(cur);
     if (casted->GetPretenureMode() == flag) {
       casted->ResetPretenureDecision();
-      bool got_marked = casted->dependent_code()->MarkCodeForDeoptimization(
-          isolate_,
-          DependentCode::kAllocationSiteTenuringChangedGroup);
-      if (got_marked) marked = true;
+      casted->set_deopt_dependent_code(true);
+      marked = true;
     }
     cur = casted->weak_next();
   }
-  if (marked) isolate_->stack_guard()->DeoptMarkedCode();
+  if (marked) isolate_->stack_guard()->DeoptMarkedAllocationSites();
 }