Added histogram to track distribution of requested idle notifications.

src/counters.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/base/platform/platform.h"
 #include "src/counters.h"
 #include "src/isolate.h"
 
@@ skipping 37 matching lines @@
   if (Enabled()) {
     // Compute the delta between start and stop, in milliseconds.
     AddSample(static_cast<int>(timer_.Elapsed().InMilliseconds()));
     timer_.Stop();
   }
   isolate()->event_logger()(name(), Logger::END);
 }
 
 
 Counters::Counters(Isolate* isolate) {
+#define HR(name, caption) name##_ = Histogram(#caption, 0, 1000, 1001, isolate);

[rmcilroy, 2014/07/25 16:09:28]

optional suggestion - if you want this to be generic, maybe you could add
arguments to HR for the range and number of buckets, then they could be
parameterized seperately for each entry in the HISTOGRAM_RANGE_LIST list, wdyt?

[rmcilroy, 2014/07/25 16:09:28]

nit - newline after ")" like those below.

[jochen (gone - plz use gerrit), 2014/07/28 08:44:43]

why cap it at 1000? We might want to allow for larger idle times in the future,
no?

Also, 1001 buckets is a lot, we typically would use 50 or 100 buckets.

[Hannes Payer (out of office), 2014/07/28 09:01:13]

git cl format moved it up :-/ I will try to force it to keep it below

[Hannes Payer (out of office), 2014/07/28 09:01:13]

Good idea, done.

[Hannes Payer (out of office), 2014/07/28 09:02:40]

Yeah, I thought so as well. I increased the max, but I would like to keep at
least a granularity of 10. For the lower numbers it is nice to have a smaller
granularity. For larger numbers I do not care.

+  HISTOGRAM_RANGE_LIST(HR)
+#undef HR
+
 #define HT(name, caption) \
     name##_ = HistogramTimer(#caption, 0, 10000, 50, isolate);
     HISTOGRAM_TIMER_LIST(HT)
 #undef HT
 
 #define HP(name, caption) \
     name##_ = Histogram(#caption, 0, 101, 100, isolate);
     HISTOGRAM_PERCENTAGE_LIST(HP)
 #undef HP
 
@@ skipping 67 matching lines @@
 
 #define SC(name)                       \
   count_of_CODE_AGE_##name##_.Reset(); \
   size_of_CODE_AGE_##name##_.Reset();
   CODE_AGE_LIST_COMPLETE(SC)
 #undef SC
 }
 
 
 void Counters::ResetHistograms() {
+#define HR(name, caption) name##_.Reset();
+  HISTOGRAM_MEMORY_LIST(HR)

[jochen (gone - plz use gerrit), 2014/07/28 08:44:43]

HISTOGRAM_RANGE_LIST?

[Hannes Payer (out of office), 2014/07/28 09:02:40]

Already fixed.

+#undef HR
+
 #define HT(name, caption) name##_.Reset();
     HISTOGRAM_TIMER_LIST(HT)
 #undef HT
 
 #define HP(name, caption) name##_.Reset();
     HISTOGRAM_PERCENTAGE_LIST(HP)
 #undef HP
 
 #define HM(name, caption) name##_.Reset();
     HISTOGRAM_MEMORY_LIST(HM)
 #undef HM
 }
 
 } }  // namespace v8::internal