Added histogram to track distribution of requested idle notifications.

BUG=397026
LOG=n
R=rmcilroy@chromium.org

Review URL: https://codereview.chromium.org/420753002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22632 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/counters.cc

@@ -55,6 +55,11 @@ void HistogramTimer::Stop() {
 
 
 Counters::Counters(Isolate* isolate) {
+#define HR(name, caption, min, max, num_buckets) \
+  name##_ = Histogram(#caption, min, max, num_buckets, isolate);
+  HISTOGRAM_RANGE_LIST(HR)
+#undef HR
+
 #define HT(name, caption) \
     name##_ = HistogramTimer(#caption, 0, 10000, 50, isolate);
     HISTOGRAM_TIMER_LIST(HT)
@@ -142,6 +147,10 @@ void Counters::ResetCounters() {
 
 
 void Counters::ResetHistograms() {
+#define HR(name, caption, min, max, num_buckets) name##_.Reset();
+  HISTOGRAM_RANGE_LIST(HR)
+#undef HR
+
 #define HT(name, caption) name##_.Reset();
     HISTOGRAM_TIMER_LIST(HT)
 #undef HT

src/counters.h

@@ -291,6 +291,9 @@ class HistogramTimerScope BASE_EMBEDDED {
 #endif
 };
 
+#define HISTOGRAM_RANGE_LIST(HR) \
+  /* Generic range histograms */ \
+  HR(gc_idle_time_allotted_in_ms, V8.GCIdleTimeAllottedInMS, 0, 10000, 101)
 
 #define HISTOGRAM_TIMER_LIST(HT)                             \
   /* Garbage collection timers. */                           \
@@ -552,6 +555,11 @@ class HistogramTimerScope BASE_EMBEDDED {
 // This file contains all the v8 counters that are in use.
 class Counters {
  public:
+#define HR(name, caption, min, max, num_buckets) \
+  Histogram* name() { return &name##_; }
+  HISTOGRAM_RANGE_LIST(HR)
+#undef HR
+
 #define HT(name, caption) \
   HistogramTimer* name() { return &name##_; }
   HISTOGRAM_TIMER_LIST(HT)
@@ -639,6 +647,10 @@ class Counters {
   void ResetHistograms();
 
  private:
+#define HR(name, caption, min, max, num_buckets) Histogram name##_;
+  HISTOGRAM_RANGE_LIST(HR)
+#undef HR
+
 #define HT(name, caption) \
   HistogramTimer name##_;
   HISTOGRAM_TIMER_LIST(HT)

src/heap.cc

@@ -54,8 +54,7 @@ Heap::Heap()
       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.
+      // be a multiple of Page::kPageSize.
       reserved_semispace_size_(8 * (kPointerSize / 4) * MB),
       max_semi_space_size_(8 * (kPointerSize / 4) * MB),
       initial_semispace_size_(Page::kPageSize),
@@ -4268,6 +4267,7 @@ bool Heap::IdleNotification(int hint) {
   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());