Tweak compaction candidate selection to avoid keeping page with low occupancy around.

src/log.cc

 // Copyright 2011 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 1503 matching lines @@
 
 
 void Logger::LowLevelLogWriteBytes(const char* bytes, int size) {
   size_t rv = fwrite(bytes, 1, size, log_->ll_output_handle_);
   ASSERT(static_cast<size_t>(size) == rv);
   USE(rv);
 }
 
 
 void Logger::LogCodeObjects() {
-  HEAP->CollectAllGarbage(Heap::kMakeHeapIterableMask);
+  HEAP->CollectAllGarbage(Heap::kMakeHeapIterableMask,
+                          "Logger::LogCodeObjects");
   HeapIterator iterator;
   AssertNoAllocation no_alloc;
   for (HeapObject* obj = iterator.next(); obj != NULL; obj = iterator.next()) {
     if (obj->IsCode()) LogCodeObject(obj);
   }
 }
 
 
 void Logger::LogExistingFunction(Handle<SharedFunctionInfo> shared,
                                  Handle<Code> code) {
@@ skipping 34 matching lines @@
     }
   } else {
     PROFILE(ISOLATE,
             CodeCreateEvent(
                 Logger::LAZY_COMPILE_TAG, *code, *shared, *func_name));
   }
 }
 
 
 void Logger::LogCompiledFunctions() {
-  HEAP->CollectAllGarbage(Heap::kMakeHeapIterableMask);
+  HEAP->CollectAllGarbage(Heap::kMakeHeapIterableMask,
+                          "Logger::LogCompiledFunctions");
   HandleScope scope;
   const int compiled_funcs_count = EnumerateCompiledFunctions(NULL, NULL);
   ScopedVector< Handle<SharedFunctionInfo> > sfis(compiled_funcs_count);
   ScopedVector< Handle<Code> > code_objects(compiled_funcs_count);
   EnumerateCompiledFunctions(sfis.start(), code_objects.start());
 
   // During iteration, there can be heap allocation due to
   // GetScriptLineNumber call.
   for (int i = 0; i < compiled_funcs_count; ++i) {
     if (*code_objects[i] == Isolate::Current()->builtins()->builtin(
         Builtins::kLazyCompile))
       continue;
     LogExistingFunction(sfis[i], code_objects[i]);
   }
 }
 
 
 void Logger::LogAccessorCallbacks() {
-  HEAP->CollectAllGarbage(Heap::kMakeHeapIterableMask);
+  HEAP->CollectAllGarbage(Heap::kMakeHeapIterableMask,
+                          "Logger::LogAccessorCallbacks");
   HeapIterator iterator;
   AssertNoAllocation no_alloc;
   for (HeapObject* obj = iterator.next(); obj != NULL; obj = iterator.next()) {
     if (!obj->IsAccessorInfo()) continue;
     AccessorInfo* ai = AccessorInfo::cast(obj);
     if (!ai->name()->IsString()) continue;
     String* name = String::cast(ai->name());
     Address getter_entry = v8::ToCData<Address>(ai->getter());
     if (getter_entry != 0) {
       PROFILE(ISOLATE, GetterCallbackEvent(name, getter_entry));
@@ skipping 160 matching lines @@
 void SamplerRegistry::RemoveActiveSampler(Sampler* sampler) {
   ASSERT(sampler->IsActive());
   ScopedLock lock(mutex_);
   ASSERT(active_samplers_ != NULL);
   bool removed = active_samplers_->RemoveElement(sampler);
   ASSERT(removed);
   USE(removed);
 }
 
 } }  // namespace v8::internal