A64: Synchronize with r18581.

src/heap.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 488 matching lines @@
   PagedSpaces spaces(this);
   for (PagedSpace* space = spaces.next();
        space != NULL;
        space = spaces.next()) {
     space->RepairFreeListsAfterBoot();
   }
 }
 
 
 void Heap::ProcessPretenuringFeedback() {
-  if (FLAG_allocation_site_pretenuring) {
+  if (FLAG_allocation_site_pretenuring &&
+      new_space_high_promotion_mode_active_) {
     int tenure_decisions = 0;
     int dont_tenure_decisions = 0;
     int allocation_mementos_found = 0;
     int allocation_sites = 0;
     int active_allocation_sites = 0;
 
     // If the scratchpad overflowed, we have to iterate over the allocation
-    // stites list.
+    // sites list.
     bool use_scratchpad =
         allocation_sites_scratchpad_length < kAllocationSiteScratchpadSize;
 
     int i = 0;
     Object* list_element = allocation_sites_list();
     while (use_scratchpad ?
               i < allocation_sites_scratchpad_length :
               list_element->IsAllocationSite()) {
       AllocationSite* site = use_scratchpad ?
         allocation_sites_scratchpad[i] : AllocationSite::cast(list_element);
-      allocation_mementos_found += site->memento_found_count()->value();
-      if (site->memento_found_count()->value() > 0) {
+      allocation_mementos_found += site->memento_found_count();
+      if (site->memento_found_count() > 0) {
         active_allocation_sites++;
       }
       if (site->DigestPretenuringFeedback()) {
         if (site->GetPretenureMode() == TENURED) {
           tenure_decisions++;
         } else {
           dont_tenure_decisions++;
         }
       }
       allocation_sites++;
@@ skipping 154 matching lines @@
 
 #if defined(DEBUG)
   ReportStatisticsAfterGC();
 #endif  // DEBUG
 #ifdef ENABLE_DEBUGGER_SUPPORT
   isolate_->debug()->AfterGarbageCollection();
 #endif  // ENABLE_DEBUGGER_SUPPORT
 }
 
 
-void Heap::CollectAllGarbage(int flags, const char* gc_reason) {
+void Heap::CollectAllGarbage(int flags,
+                             const char* gc_reason,
+                             const v8::GCCallbackFlags gc_callback_flags) {
   // Since we are ignoring the return value, the exact choice of space does
   // not matter, so long as we do not specify NEW_SPACE, which would not
   // cause a full GC.
   mark_compact_collector_.SetFlags(flags);
-  CollectGarbage(OLD_POINTER_SPACE, gc_reason);
+  CollectGarbage(OLD_POINTER_SPACE, gc_reason, gc_callback_flags);
   mark_compact_collector_.SetFlags(kNoGCFlags);
 }
 
 
 void Heap::CollectAllAvailableGarbage(const char* gc_reason) {
   // Since we are ignoring the return value, the exact choice of space does
   // not matter, so long as we do not specify NEW_SPACE, which would not
   // cause a full GC.
   // Major GC would invoke weak handle callbacks on weakly reachable
   // handles, but won't collect weakly reachable objects until next
@@ skipping 22 matching lines @@
   mark_compact_collector()->SetFlags(kNoGCFlags);
   new_space_.Shrink();
   UncommitFromSpace();
   incremental_marking()->UncommitMarkingDeque();
 }
 
 
 bool Heap::CollectGarbage(AllocationSpace space,
                           GarbageCollector collector,
                           const char* gc_reason,
-                          const char* collector_reason) {
+                          const char* collector_reason,
+                          const v8::GCCallbackFlags gc_callback_flags) {
   // The VM is in the GC state until exiting this function.
   VMState<GC> state(isolate_);
 
 #ifdef DEBUG
   // Reset the allocation timeout to the GC interval, but make sure to
   // allow at least a few allocations after a collection. The reason
   // for this is that we have a lot of allocation sequences and we
   // assume that a garbage collection will allow the subsequent
   // allocation attempts to go through.
   allocation_timeout_ = Max(6, FLAG_gc_interval);
@@ skipping 34 matching lines @@
     tracer.set_gc_count(gc_count_);
 
     // Tell the tracer which collector we've selected.
     tracer.set_collector(collector);
 
     {
       HistogramTimerScope histogram_timer_scope(
           (collector == SCAVENGER) ? isolate_->counters()->gc_scavenger()
                                    : isolate_->counters()->gc_compactor());
       next_gc_likely_to_collect_more =
-          PerformGarbageCollection(collector, &tracer);
+          PerformGarbageCollection(collector, &tracer, gc_callback_flags);
     }
 
     GarbageCollectionEpilogue();
   }
 
   // Start incremental marking for the next cycle. The heap snapshot
   // generator needs incremental marking to stay off after it aborted.
   if (!mark_compact_collector()->abort_incremental_marking() &&
       incremental_marking()->IsStopped() &&
       incremental_marking()->WorthActivating() &&
@@ skipping 206 matching lines @@
     set_survival_rate_trend(DECREASING);
   } else if (survival_rate_diff < -kYoungSurvivalRateAllowedDeviation) {
     set_survival_rate_trend(INCREASING);
   } else {
     set_survival_rate_trend(STABLE);
   }
 
   survival_rate_ = survival_rate;
 }
 
-bool Heap::PerformGarbageCollection(GarbageCollector collector,
-                                    GCTracer* tracer) {
+bool Heap::PerformGarbageCollection(
+    GarbageCollector collector,
+    GCTracer* tracer,
+    const v8::GCCallbackFlags gc_callback_flags) {
   bool next_gc_likely_to_collect_more = false;
 
   if (collector != SCAVENGER) {
     PROFILE(isolate_, CodeMovingGCEvent());
   }
 
 #ifdef VERIFY_HEAP
   if (FLAG_verify_heap) {
     VerifyStringTable(this);
   }
@@ skipping 47 matching lines @@
       IsHighSurvivalRate()) {
     // Stable high survival rates even though young generation is at
     // maximum capacity indicates that most objects will be promoted.
     // To decrease scavenger pauses and final mark-sweep pauses, we
     // have to limit maximal capacity of the young generation.
     SetNewSpaceHighPromotionModeActive(true);
     if (FLAG_trace_gc) {
       PrintPID("Limited new space size due to high promotion rate: %d MB\n",
                new_space_.InitialCapacity() / MB);
     }
-    // Support for global pre-tenuring uses the high promotion mode as a
-    // heuristic indicator of whether to pretenure or not, we trigger
-    // deoptimization here to take advantage of pre-tenuring as soon as
-    // possible.
+    // The high promotion mode is our indicator to turn on pretenuring. We have
+    // to deoptimize all optimized code in global pretenuring mode and all
+    // code which should be tenured in local pretenuring mode.
     if (FLAG_pretenuring) {
-      isolate_->stack_guard()->FullDeopt();
+      if (FLAG_allocation_site_pretenuring) {
+        ResetAllAllocationSitesDependentCode(NOT_TENURED);
+      } else {
+        isolate_->stack_guard()->FullDeopt();
+      }
     }
   } else if (new_space_high_promotion_mode_active_ &&
       IsStableOrDecreasingSurvivalTrend() &&
       IsLowSurvivalRate()) {
     // Decreasing low survival rates might indicate that the above high
     // promotion mode is over and we should allow the young generation
     // to grow again.
     SetNewSpaceHighPromotionModeActive(false);
     if (FLAG_trace_gc) {
       PrintPID("Unlimited new space size due to low promotion rate: %d MB\n",
                new_space_.MaximumCapacity() / MB);
     }
-    // Trigger deoptimization here to turn off pre-tenuring as soon as
+    // Trigger deoptimization here to turn off global pretenuring as soon as
     // possible.
-    if (FLAG_pretenuring) {
+    if (FLAG_pretenuring && !FLAG_allocation_site_pretenuring) {
       isolate_->stack_guard()->FullDeopt();
     }
   }
 
   if (new_space_high_promotion_mode_active_ &&
       new_space_.Capacity() > new_space_.InitialCapacity()) {
     new_space_.Shrink();
   }
 
   isolate_->counters()->objs_since_last_young()->Set(0);
@@ skipping 19 matching lines @@
   if (collector == MARK_COMPACTOR) {
     // Register the amount of external allocated memory.
     amount_of_external_allocated_memory_at_last_global_gc_ =
         amount_of_external_allocated_memory_;
   }
 
   {
     GCTracer::Scope scope(tracer, GCTracer::Scope::EXTERNAL);
     VMState<EXTERNAL> state(isolate_);
     HandleScope handle_scope(isolate_);
-    CallGCEpilogueCallbacks(gc_type);
+    CallGCEpilogueCallbacks(gc_type, gc_callback_flags);
   }
 
 #ifdef VERIFY_HEAP
   if (FLAG_verify_heap) {
     VerifyStringTable(this);
   }
 #endif
 
   return next_gc_likely_to_collect_more;
 }
 
 
 void Heap::CallGCPrologueCallbacks(GCType gc_type, GCCallbackFlags flags) {
   for (int i = 0; i < gc_prologue_callbacks_.length(); ++i) {
     if (gc_type & gc_prologue_callbacks_[i].gc_type) {
       if (!gc_prologue_callbacks_[i].pass_isolate_) {
         v8::GCPrologueCallback callback =
             reinterpret_cast<v8::GCPrologueCallback>(
                 gc_prologue_callbacks_[i].callback);
         callback(gc_type, flags);
       } else {
         v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(this->isolate());
         gc_prologue_callbacks_[i].callback(isolate, gc_type, flags);
       }
     }
   }
 }
 
 
-void Heap::CallGCEpilogueCallbacks(GCType gc_type) {
+void Heap::CallGCEpilogueCallbacks(GCType gc_type,
+                                   GCCallbackFlags gc_callback_flags) {
   for (int i = 0; i < gc_epilogue_callbacks_.length(); ++i) {
     if (gc_type & gc_epilogue_callbacks_[i].gc_type) {
       if (!gc_epilogue_callbacks_[i].pass_isolate_) {
         v8::GCPrologueCallback callback =
             reinterpret_cast<v8::GCPrologueCallback>(
                 gc_epilogue_callbacks_[i].callback);
-        callback(gc_type, kNoGCCallbackFlags);
+        callback(gc_type, gc_callback_flags);
       } else {
         v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(this->isolate());
         gc_epilogue_callbacks_[i].callback(
-            isolate, gc_type, kNoGCCallbackFlags);
+            isolate, gc_type, gc_callback_flags);
       }
     }
   }
 }
 
 
 void Heap::MarkCompact(GCTracer* tracer) {
   gc_state_ = MARK_COMPACT;
   LOG(isolate_, ResourceEvent("markcompact", "begin"));
 
+  uint64_t size_of_objects_before_gc = SizeOfObjects();
+
   mark_compact_collector_.Prepare(tracer);
 
   ms_count_++;
   tracer->set_full_gc_count(ms_count_);
 
   MarkCompactPrologue();
 
   mark_compact_collector_.CollectGarbage();
 
   LOG(isolate_, ResourceEvent("markcompact", "end"));
 
   gc_state_ = NOT_IN_GC;
 
   isolate_->counters()->objs_since_last_full()->Set(0);
 
   flush_monomorphic_ics_ = false;
+
+  if (FLAG_allocation_site_pretenuring) {
+    EvaluateOldSpaceLocalPretenuring(size_of_objects_before_gc);
+  }
 }
 
 
 void Heap::MarkCompactPrologue() {
   // At any old GC clear the keyed lookup cache to enable collection of unused
   // maps.
   isolate_->keyed_lookup_cache()->Clear();
   isolate_->context_slot_cache()->Clear();
   isolate_->descriptor_lookup_cache()->Clear();
   RegExpResultsCache::Clear(string_split_cache());
@@ skipping 718 matching lines @@
 void Heap::ProcessAllocationSites(WeakObjectRetainer* retainer,
                                   bool record_slots) {
   Object* allocation_site_obj =
       VisitWeakList<AllocationSite>(this,
                                     allocation_sites_list(),
                                     retainer, record_slots);
   set_allocation_sites_list(allocation_site_obj);
 }
 
 
+void Heap::ResetAllAllocationSitesDependentCode(PretenureFlag flag) {
+  Object* cur = allocation_sites_list();
+  while (cur->IsAllocationSite()) {
+    AllocationSite* casted = AllocationSite::cast(cur);
+    if (casted->GetPretenureMode() == flag) {
+      casted->ResetPretenureDecision();
+    }
+    cur = casted->weak_next();
+  }
+}
+
+
+void Heap::EvaluateOldSpaceLocalPretenuring(
+    uint64_t size_of_objects_before_gc) {
+  uint64_t size_of_objects_after_gc = SizeOfObjects();
+  double old_generation_survival_rate =
+      (static_cast<double>(size_of_objects_after_gc) * 100) /
+          static_cast<double>(size_of_objects_before_gc);
+
+  if (old_generation_survival_rate < kOldSurvivalRateLowThreshold) {
+    // Too many objects died in the old generation, pretenuring of wrong
+    // allocation sites may be the cause for that. We have to deopt all
+    // dependent code registered in the allocation sites to re-evaluate
+    // our pretenuring decisions.
+    ResetAllAllocationSitesDependentCode(TENURED);
+    if (FLAG_trace_pretenuring) {
+      PrintF("Deopt all allocation sites dependent code due to low survival "
+             "rate in the old generation %f\n", old_generation_survival_rate);
+    }
+  }
+}
+
+
 void Heap::VisitExternalResources(v8::ExternalResourceVisitor* visitor) {
   DisallowHeapAllocation no_allocation;
   // All external strings are listed in the external string table.
 
   class ExternalStringTableVisitorAdapter : public ObjectVisitor {
    public:
     explicit ExternalStringTableVisitorAdapter(
         v8::ExternalResourceVisitor* visitor) : visitor_(visitor) {}
     virtual void VisitPointers(Object** start, Object** end) {
       for (Object** p = start; p < end; p++) {
@@ skipping 5761 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   OS::MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   OS::MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 
 } }  // namespace v8::internal