[scheduler] Discard anomalously long tasks and bump metrics version.

third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc

 // Copyright 2014 The Chromium 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 "platform/scheduler/renderer/renderer_scheduler_impl.h"
 
 #include "base/bind.h"
 #include "base/debug/stack_trace.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
@@ skipping 35 matching lines @@
 const double kFastCompositingIdleTimeThreshold = .2;
 constexpr base::TimeDelta kThreadLoadTrackerReportingInterval =
     base::TimeDelta::FromMinutes(1);
 constexpr base::TimeDelta kThreadLoadTrackerWaitingPeriodBeforeReporting =
     base::TimeDelta::FromMinutes(2);
 // We do not throttle anything while audio is played and shortly after that.
 constexpr base::TimeDelta kThrottlingDelayAfterAudioIsPlayed =
     base::TimeDelta::FromSeconds(5);
 constexpr base::TimeDelta kQueueingTimeWindowDuration =
     base::TimeDelta::FromSeconds(1);
-// Maximal bound on task duration for reporting.
-constexpr base::TimeDelta kMaxTaskDurationForReporting =
-    base::TimeDelta::FromMinutes(1);
+// Threshold for discarding ultra-long tasks. It is assumed that ultra-long
+// tasks are reporting glitches (e.g. system falling asleep in the middle
+// of the task).
+constexpr base::TimeDelta kLongTaskDiscardingThreshold =
+    base::TimeDelta::FromSeconds(30);
 
 void ReportForegroundRendererTaskLoad(base::TimeTicks time, double load) {
   if (!blink::RuntimeEnabledFeatures::timerThrottlingForBackgroundTabsEnabled())
     return;
 
   int load_percentage = static_cast<int>(load * 100);
   DCHECK_LE(load_percentage, 100);
 
-  UMA_HISTOGRAM_PERCENTAGE("RendererScheduler.ForegroundRendererMainThreadLoad",
-                           load_percentage);
+  UMA_HISTOGRAM_PERCENTAGE(
+      "RendererScheduler.ForegroundRendererMainThreadLoad2", load_percentage);
   TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
                  "RendererScheduler.ForegroundRendererLoad", load_percentage);
 }
 
 void ReportBackgroundRendererTaskLoad(base::TimeTicks time, double load) {
   if (!blink::RuntimeEnabledFeatures::timerThrottlingForBackgroundTabsEnabled())
     return;
 
   int load_percentage = static_cast<int>(load * 100);
   DCHECK_LE(load_percentage, 100);
 
-  UMA_HISTOGRAM_PERCENTAGE("RendererScheduler.BackgroundRendererMainThreadLoad",
-                           load_percentage);
+  UMA_HISTOGRAM_PERCENTAGE(
+      "RendererScheduler.BackgroundRendererMainThreadLoad2", load_percentage);
   TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
                  "RendererScheduler.BackgroundRendererLoad", load_percentage);
 }
 
 }  // namespace
 
 RendererSchedulerImpl::RendererSchedulerImpl(
     scoped_refptr<SchedulerTqmDelegate> main_task_runner)
     : helper_(main_task_runner),
       idle_helper_(&helper_,
@@ skipping 121 matching lines @@
       have_reported_blocking_intervention_in_current_policy(false),
       have_reported_blocking_intervention_since_navigation(false),
       has_visible_render_widget_with_touch_handler(false),
       begin_frame_not_expected_soon(false),
       in_idle_period_for_testing(false),
       use_virtual_time(false),
       is_audio_playing(false),
       rail_mode_observer(nullptr),
       wake_up_budget_pool(nullptr),
       task_duration_per_queue_type_histogram(base::Histogram::FactoryGet(
-          "RendererScheduler.TaskDurationPerQueueType",
+          "RendererScheduler.TaskDurationPerQueueType2",
           1,
           static_cast<int>(TaskQueue::QueueType::COUNT),
           static_cast<int>(TaskQueue::QueueType::COUNT) + 1,
           base::HistogramBase::kUmaTargetedHistogramFlag)) {
   foreground_main_thread_load_tracker.Resume(now);
 }
 
 RendererSchedulerImpl::MainThreadOnly::~MainThreadOnly() {}
 
 RendererSchedulerImpl::AnyThread::AnyThread()
@@ skipping 1600 matching lines @@
       MonotonicTimeInSecondsToTimeTicks(start_time);
   base::TimeTicks end_time_ticks = MonotonicTimeInSecondsToTimeTicks(end_time);
 
   seqlock_queueing_time_estimator_.seqlock.WriteBegin();
   seqlock_queueing_time_estimator_.data.OnTopLevelTaskCompleted(end_time_ticks);
   seqlock_queueing_time_estimator_.seqlock.WriteEnd();
 
   task_queue_throttler()->OnTaskRunTimeReported(task_queue, start_time_ticks,
                                                 end_time_ticks);
 
+  // TODO(altimin): Per-page metrics should also be considered.
+  RecordTaskMetrics(task_queue->GetQueueType(), start_time_ticks,
+                    end_time_ticks);
+}
+
+void RendererSchedulerImpl::RecordTaskMetrics(TaskQueue::QueueType queue_type,
+                                              base::TimeTicks start_time,
+                                              base::TimeTicks end_time) {
+  base::TimeDelta duration = end_time - start_time;
+  if (duration > kLongTaskDiscardingThreshold)
+    return;
+
+  UMA_HISTOGRAM_CUSTOM_COUNTS("RendererScheduler.TaskTime2",
+                              duration.InMicroseconds(), 1, 1000 * 1000, 50);
+
   // We want to measure thread time here, but for efficiency reasons
   // we stick with wall time.
   GetMainThreadOnly().foreground_main_thread_load_tracker.RecordTaskTime(
-      start_time_ticks, end_time_ticks);
+      start_time, end_time);
   GetMainThreadOnly().background_main_thread_load_tracker.RecordTaskTime(
-      start_time_ticks, end_time_ticks);
-
-  // TODO(altimin): Per-page metrics should also be considered.
-  RecordTaskMetrics(task_queue->GetQueueType(),
-                    end_time_ticks - start_time_ticks);
-}
-
-void RendererSchedulerImpl::RecordTaskMetrics(TaskQueue::QueueType queue_type,
-                                              base::TimeDelta duration) {
-  UMA_HISTOGRAM_CUSTOM_COUNTS("RendererScheduler.TaskTime",
-                              duration.InMicroseconds(), 1, 1000 * 1000, 50);
+      start_time, end_time);
 
   // TODO(altimin): See whether this metric is still useful after
   // adding RendererScheduler.TaskDurationPerQueueType.
-  UMA_HISTOGRAM_ENUMERATION("RendererScheduler.NumberOfTasksPerQueueType",
+  UMA_HISTOGRAM_ENUMERATION("RendererScheduler.NumberOfTasksPerQueueType2",
                             static_cast<int>(queue_type),
                             static_cast<int>(TaskQueue::QueueType::COUNT));
 
   RecordTaskDurationPerQueueType(queue_type, duration);
 }
 
 void RendererSchedulerImpl::RecordTaskDurationPerQueueType(
     TaskQueue::QueueType queue_type,
     base::TimeDelta duration) {
-  duration = std::min(duration, kMaxTaskDurationForReporting);
-
   // Report only whole milliseconds to avoid overflow.
   base::TimeDelta& unreported_duration =
       GetMainThreadOnly()
           .unreported_task_duration[static_cast<int>(queue_type)];
   unreported_duration += duration;
   int64_t milliseconds = unreported_duration.InMilliseconds();
   if (milliseconds > 0) {
     unreported_duration -= base::TimeDelta::FromMilliseconds(milliseconds);
     GetMainThreadOnly().task_duration_per_queue_type_histogram->AddCount(
         static_cast<int>(queue_type), static_cast<int>(milliseconds));
@@ skipping 169 matching lines @@
     case TimeDomainType::VIRTUAL:
       return "virtual";
     default:
       NOTREACHED();
       return nullptr;
   }
 }
 
 }  // namespace scheduler
 }  // namespace blink