Added histogram to track distribution of requested idle notifications.

src/heap.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/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/once.h"
 #include "src/base/utils/random-number-generator.h"
@@ skipping 35 matching lines @@
 
 namespace v8 {
 namespace internal {
 
 
 Heap::Heap()
     : amount_of_external_allocated_memory_(0),
       amount_of_external_allocated_memory_at_last_global_gc_(0),
       isolate_(NULL),
       code_range_size_(0),
-// semispace_size_ should be a power of 2 and old_generation_size_ should be
-// a multiple of Page::kPageSize.
+      // semispace_size_ should be a power of 2 and old_generation_size_ should
+      // be a multiple of Page::kPageSize.
       reserved_semispace_size_(8 * (kPointerSize / 4) * MB),
-      max_semi_space_size_(8 * (kPointerSize / 4)  * MB),
+      max_semi_space_size_(8 * (kPointerSize / 4) * MB),
       initial_semispace_size_(Page::kPageSize),
       max_old_generation_size_(700ul * (kPointerSize / 4) * MB),
       max_executable_size_(256ul * (kPointerSize / 4) * MB),
-// Variables set based on semispace_size_ and old_generation_size_ in
-// ConfigureHeap.
-// Will be 4 * reserved_semispace_size_ to ensure that young
-// generation can be aligned to its size.
+      // Variables set based on semispace_size_ and old_generation_size_ in
+      // ConfigureHeap.
+      // Will be 4 * reserved_semispace_size_ to ensure that young
+      // generation can be aligned to its size.
       maximum_committed_(0),
       survived_since_last_expansion_(0),
       sweep_generation_(0),
       always_allocate_scope_depth_(0),
       contexts_disposed_(0),
       global_ic_age_(0),
       flush_monomorphic_ics_(false),
       scan_on_scavenge_pages_(0),
       new_space_(this),
       old_pointer_space_(NULL),
@@ skipping 4184 matching lines @@
   const int kMinHintForIncrementalMarking = 10;
   // Minimal hint that allows to do full GC.
   const int kMinHintForFullGC = 100;
   intptr_t size_factor = Min(Max(hint, 20), kMaxHint) / 4;
   // The size factor is in range [5..250]. The numbers here are chosen from
   // experiments. If you changes them, make sure to test with
   // chrome/performance_ui_tests --gtest_filter="GeneralMixMemoryTest.*
   intptr_t step_size =
       size_factor * IncrementalMarking::kAllocatedThreshold;
 
+  isolate()->counters()->gc_idle_time_allotted_in_ms()->AddSample(hint);
   HistogramTimerScope idle_notification_scope(
       isolate_->counters()->gc_idle_notification());
 
   if (contexts_disposed_ > 0) {
     contexts_disposed_ = 0;
     int mark_sweep_time = Min(TimeMarkSweepWouldTakeInMs(), 1000);
     if (hint >= mark_sweep_time && !FLAG_expose_gc &&
         incremental_marking()->IsStopped()) {
       HistogramTimerScope scope(isolate_->counters()->gc_context());
       CollectAllGarbage(kReduceMemoryFootprintMask,
@@ skipping 2169 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
 
   MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 
 } }  // namespace v8::internal