Bookkeeping for allocation site pretenuring

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index b5fe18454e31005d64bb7e611a25dd60449eea67..4eaed4119fc8bbb2b6ec1311c8cc5cee52aa8ed5 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -87,7 +87,6 @@ Heap::Heap()
       contexts_disposed_(0),
       global_ic_age_(0),
       flush_monomorphic_ics_(false),
-      allocation_mementos_found_(0),
       scan_on_scavenge_pages_(0),
       new_space_(this),
       old_pointer_space_(NULL),
@@ -506,6 +505,42 @@ void Heap::RepairFreeListsAfterBoot() {
 
 
 void Heap::GarbageCollectionEpilogue() {
+  if (FLAG_allocation_site_pretenuring) {
+    int tenure_decisions = 0;
+    int dont_tenure_decisions = 0;
+    int allocation_mementos_found = 0;
+
+    Object* cur = allocation_sites_list();
+    if (cur->IsAllocationSite()) {

[Hannes Payer (out of office), 2013/11/25 11:45:52]

I guess the if is not needed.

[mvstanton, 2013/11/25 13:49:18]

Done.

+      while (cur->IsAllocationSite()) {
+        AllocationSite* casted = AllocationSite::cast(cur);
+        allocation_mementos_found += casted->memento_found_count()->value();
+        if (casted->DigestPretenuringFeedback()) {
+          if (casted->GetPretenureMode() == TENURED) {
+            tenure_decisions++;
+          } else {
+            dont_tenure_decisions++;
+          }
+        }
+        cur = casted->weak_next();
+      }
+    }
+
+    // TODO(mvstanton): Pretenure decisions are only made once for an allocation
+    // site. Find a sane way to decide about revisiting the decision later.
+
+    if (FLAG_trace_track_allocation_sites &&
+        (allocation_mementos_found > 0 ||
+         tenure_decisions > 0 ||
+         dont_tenure_decisions > 0)) {
+      PrintF("GC: (#mementos, #tenure decisions, #donttenure decisions) "
+             "(%d, %d, %d)\n",
+             allocation_mementos_found,
+             tenure_decisions,
+             dont_tenure_decisions);
+    }
+  }
+
   store_buffer()->GCEpilogue();
 
   // In release mode, we only zap the from space under heap verification.
@@ -1393,8 +1428,6 @@ class ScavengeWeakObjectRetainer : public WeakObjectRetainer {
 void Heap::Scavenge() {
   RelocationLock relocation_lock(this);
 
-  allocation_mementos_found_ = 0;
-
 #ifdef VERIFY_HEAP
   if (FLAG_verify_heap) VerifyNonPointerSpacePointers(this);
 #endif
@@ -1542,11 +1575,6 @@ void Heap::Scavenge() {
   gc_state_ = NOT_IN_GC;
 
   scavenges_since_last_idle_round_++;
-
-  if (FLAG_trace_track_allocation_sites && allocation_mementos_found_ > 0) {
-    PrintF("AllocationMementos found during scavenge = %d\n",
-           allocation_mementos_found_);
-  }
 }
 
 
@@ -4376,6 +4404,9 @@ MaybeObject* Heap::AllocateWithAllocationSite(Map* map, AllocationSpace space,
   alloc_memento->set_map_no_write_barrier(allocation_memento_map());
   ASSERT(allocation_site->map() == allocation_site_map());
   alloc_memento->set_allocation_site(*allocation_site, SKIP_WRITE_BARRIER);
+  if (FLAG_allocation_site_pretenuring) {
+    allocation_site->IncrementMementoCreateCount();
+  }
   return result;
 }
 
@@ -4808,8 +4839,7 @@ MaybeObject* Heap::CopyJSObject(JSObject* source, AllocationSite* site) {
   int object_size = map->instance_size();
   Object* clone;
 
-  ASSERT(site == NULL || (AllocationSite::CanTrack(map->instance_type()) &&
-                          map->instance_type() == JS_ARRAY_TYPE));
+  ASSERT(site == NULL || AllocationSite::CanTrack(map->instance_type()));
 
   WriteBarrierMode wb_mode = UPDATE_WRITE_BARRIER;
 
@@ -4851,6 +4881,9 @@ MaybeObject* Heap::CopyJSObject(JSObject* source, AllocationSite* site) {
       alloc_memento->set_map_no_write_barrier(allocation_memento_map());
       ASSERT(site->map() == allocation_site_map());
       alloc_memento->set_allocation_site(site, SKIP_WRITE_BARRIER);
+      if (FLAG_allocation_site_pretenuring) {
+        site->IncrementMementoCreateCount();
+      }
       HeapProfiler* profiler = isolate()->heap_profiler();
       if (profiler->is_tracking_allocations()) {
         profiler->UpdateObjectSizeEvent(HeapObject::cast(clone)->address(),