Reporting top cpu and memory consumers via rappor on chromeos

chrome/browser/chromeos/resource_reporter/resource_reporter.cc

Index: chrome/browser/chromeos/resource_reporter/resource_reporter.cc
diff --git a/chrome/browser/chromeos/resource_reporter/resource_reporter.cc b/chrome/browser/chromeos/resource_reporter/resource_reporter.cc
new file mode 100644
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+++ b/chrome/browser/chromeos/resource_reporter/resource_reporter.cc
@@ -0,0 +1,418 @@
+// Copyright 2015 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 "chrome/browser/chromeos/resource_reporter/resource_reporter.h"
+
+#include <stdint.h>
+
+#include <queue>
+
+#include "base/bind.h"
+#include "base/memory/singleton.h"
+#include "base/rand_util.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/sys_info.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/task_management/task_manager_interface.h"
+#include "components/rappor/rappor_service.h"
+#include "content/public/browser/browser_thread.h"
+
+namespace chromeos {
+
+namespace {
+
+// The task manager refresh interval, currently at 1 minute.
+const int64_t kRefreshIntervalSeconds = 60;
+
+// 1 GB in bytes.
+const int64_t kMemory1GB = 1024 * 1024 * 1024;
+
+// 800 MB in bytes.
+const int64_t kMemory800MB = 800 * 1024 * 1024;
+
+// 600 MB in bytes.
+const int64_t kMemory600MB = 600 * 1024 * 1024;
+
+// 400 MB in bytes.
+const int64_t kMemory400MB = 400 * 1024 * 1024;
+
+// 200 MB in bytes.
+const int64_t kMemory200MB = 200 * 1024 * 1024;
+
+// The name of the Rappor metric to report the CPU usage.
+const char kCpuRapporMetric[] = "ResourceReporter.Cpu";
+
+// The name of the Rappor metric to report the memory usage.
+const char kMemoryRapporMetric[] = "ResourceReporter.Memory";
+
+// The name of the string field of the Rappor metrics in which we'll record the
+// task's Rappor sample name.
+const char kRapporTaskStringField[] = "task";
+
+// The name of the flags field of the Rappor metrics in which we'll store the
+// priority of the process on which the task is running.
+const char kRapporPriorityFlagsField[] = "priority";
+
+// The name of the flags field of the CPU usage Rappor metrics in which we'll
+// record the number of cores in the current system.
+const char kRapporNumCoresRangeFlagsField[] = "num_cores_range";
+
+// The name of the flags field of the Rappor metrics in which we'll store the
+// CPU / memory usage ranges.
+const char kRapporUsageRangeFlagsField[] = "usage_range";
+
+// Currently set to be one day.
+const int kMinimumTimeBetweenReportsInMS = 1 * 24 * 60 * 60 * 1000;
+
+// A functor to sort the TaskRecords by their |cpu|.
+struct TaskRecordByCpuSorter {
+  bool operator()(ResourceReporter::TaskRecord* const& lhs,
+                  ResourceReporter::TaskRecord* const& rhs) const {
+    if (lhs->cpu == rhs->cpu)
+      return lhs->id < rhs->id;
+    return lhs->cpu < rhs->cpu;
+  }
+};
+
+// A functor to sort the TaskRecords by their |memory|.
+struct TaskRecordByMemorySorter {
+  bool operator()(ResourceReporter::TaskRecord* const& lhs,
+                  ResourceReporter::TaskRecord* const& rhs) const {
+    if (lhs->memory == rhs->memory)
+      return lhs->id < rhs->id;
+    return lhs->memory < rhs->memory;
+  }
+};
+
+}  // namespace
+
+ResourceReporter::TaskRecord::TaskRecord(task_management::TaskId the_id)
+    : id(the_id), cpu(0.0), memory(0), is_background(false) {
+}
+
+ResourceReporter::TaskRecord::TaskRecord(task_management::TaskId the_id,
+                                         const std::string& task_name,
+                                         double the_cpu,
+                                         int64_t the_memory,
+                                         bool background)
+    : id(the_id),
+      task_name_for_rappor(task_name),
+      cpu(the_cpu),
+      memory(the_memory),
+      is_background(background) {
+}
+
+ResourceReporter::~ResourceReporter() {
+}
+
+// static
+ResourceReporter* ResourceReporter::GetInstance() {
+  return base::Singleton<ResourceReporter>::get();
+}
+
+void ResourceReporter::StartMonitoring() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  if (is_monitoring_)
+    return;
+
+  is_monitoring_ = true;
+  task_management::TaskManagerInterface::GetTaskManager()->AddObserver(this);
+  memory_pressure_listener_.reset(new base::MemoryPressureListener(
+      base::Bind(&ResourceReporter::OnMemoryPressure, base::Unretained(this))));
+}
+
+void ResourceReporter::StopMonitoring() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  if (!is_monitoring_)
+    return;
+
+  is_monitoring_ = false;
+  memory_pressure_listener_.reset();
+  task_management::TaskManagerInterface::GetTaskManager()->RemoveObserver(this);
+}
+
+void ResourceReporter::OnTaskAdded(task_management::TaskId id) {
+  // Ignore this event.
+}
+
+void ResourceReporter::OnTaskToBeRemoved(task_management::TaskId id) {
+  auto itr = task_records_.find(id);
+  if (itr == task_records_.end())
+    return;
+
+  // Must be erased from the sorted set first.
+  // Note: this could mean that the sorted records are now less than
+  // |kTopConsumerCount| with other records in |task_records_| that can be
+  // added now. That's ok, we ignore this case.
+  auto cpu_itr = std::find(task_records_by_cpu_.begin(),
+                           task_records_by_cpu_.end(),
+                           itr->second.get());
+  if (cpu_itr != task_records_by_cpu_.end())
+    task_records_by_cpu_.erase(cpu_itr);
+
+  auto memory_itr = std::find(task_records_by_memory_.begin(),
+                              task_records_by_memory_.end(),
+                              itr->second.get());
+  if (memory_itr != task_records_by_memory_.end())
+    task_records_by_memory_.erase(memory_itr);
+
+  task_records_.erase(itr);
+}
+
+void ResourceReporter::OnTasksRefreshed(
+    const task_management::TaskIdList& task_ids) {
+  // A priority queue to sort the task records by their |cpu|. Greatest |cpu|
+  // first.
+  std::priority_queue<TaskRecord*,
+                      std::vector<TaskRecord*>,
+                      TaskRecordByCpuSorter> records_by_cpu_queue;
+  // A priority queue to sort the task records by their |memory|. Greatest
+  // |memory| first.
+  std::priority_queue<TaskRecord*,
+                      std::vector<TaskRecord*>,
+                      TaskRecordByMemorySorter> records_by_memory_queue;
+  task_records_by_cpu_.clear();
+  task_records_by_cpu_.reserve(kTopConsumersCount);
+  task_records_by_memory_.clear();
+  task_records_by_memory_.reserve(kTopConsumersCount);
+
+  for (const auto& id : task_ids) {
+    const double cpu_usage = observed_task_manager()->GetCpuUsage(id);
+    const int64_t memory_usage =
+        observed_task_manager()->GetPhysicalMemoryUsage(id);
+
+    // Browser and GPU processes are reported later using UMA histograms as they
+    // don't have any privacy issues.
+    const auto task_type = observed_task_manager()->GetType(id);
+    switch (task_type) {
+      case task_management::Task::UNKNOWN:
+      case task_management::Task::ZYGOTE:
+        break;
+
+      case task_management::Task::BROWSER:
+        last_browser_process_cpu_ = cpu_usage;
+        last_browser_process_memory_ = memory_usage != -1 ? memory_usage : 0;
+        break;
+
+      case task_management::Task::GPU:
+        last_gpu_process_cpu_ = cpu_usage;
+        last_gpu_process_memory_ = memory_usage != -1 ? memory_usage : 0;
+        break;
+
+      default:
+        // Other tasks types will be reported using Rappor.
+        TaskRecord* task_data = nullptr;
+        auto itr = task_records_.find(id);
+        if (itr == task_records_.end()) {
+          task_data = new TaskRecord(id);
+          task_records_[id] = make_scoped_ptr(task_data);
+        } else {
+          task_data = itr->second.get();
+        }
+
+        DCHECK_EQ(task_data->id, id);
+        task_data->task_name_for_rappor =
+            observed_task_manager()->GetTaskNameForRappor(id);
+        task_data->cpu = cpu_usage;
+        task_data->memory = memory_usage;
+        task_data->is_background =
+            observed_task_manager()->IsTaskOnBackgroundedProcess(id);
+
+        // Push only valid or useful data to both priority queues. They might
+        // end up having more records than |kTopConsumerCount|, that's fine.
+        // We'll take care of that next.
+        if (task_data->cpu > 0)
+          records_by_cpu_queue.push(task_data);
+        if (task_data->memory > 0)
+          records_by_memory_queue.push(task_data);
+    }
+  }
+
+  // Sort the |kTopConsumersCount| task records by their CPU and memory usage
+  // and assign weights for each of them based on their order.
+  int cpu_current_weight =
+      std::min(records_by_cpu_queue.size(), kTopConsumersCount);
+  while (!records_by_cpu_queue.empty() &&
+         task_records_by_cpu_.size() < kTopConsumersCount) {
+    task_records_by_cpu_.push_back(records_by_cpu_queue.top());
+    task_records_by_cpu_.back()->cpu_weight = cpu_current_weight--;

[Steven Holte, 2015/11/17 23:42:04]

I thought the idea was to just use task_record->cpu and task_record->memory for
the weight?

[afakhry, 2015/11/18 01:06:51]

The weights are derived from the cpu and memory values, since it is assigned
based on how the task records are sorted by cpu or memory.
Are there any rules for the values of the weights? For example, do they have to
be in the range [0, 1]?

In this design, the weights are values 1, 2, 3, ... <= kTopConsumersCount, where
1 is the lowest weight, given to the task using the least amount of cpu or
memory.

[Steven Holte, 2015/11/18 02:32:35]

The sampling algorithm you are using appears to work with any positive valued
weights,
i.e. using weights = 200, 100, 50, 50 should get chosen with probabilities 50%,
25%, 12.5%, 12.5%
it actually doesn't require you to sort the records either.

I'm not sure what the advantage of using weights as 1, 2, 3, ... <=
kTopConsumersCount as opposed to just #bytes or percentage of cpu usage is?

+    records_by_cpu_queue.pop();
+  }
+
+  int memory_current_weight =
+      std::min(records_by_memory_queue.size(), kTopConsumersCount);
+  while (!records_by_memory_queue.empty() &&
+         task_records_by_memory_.size() < kTopConsumersCount) {
+    task_records_by_memory_.push_back(records_by_memory_queue.top());
+    task_records_by_memory_.back()->memory_weight = memory_current_weight--;
+    records_by_memory_queue.pop();
+  }
+}
+
+// static
+const size_t ResourceReporter::kTopConsumersCount = 10U;
+
+ResourceReporter::ResourceReporter()
+    : TaskManagerObserver(base::TimeDelta::FromSeconds(kRefreshIntervalSeconds),
+                          task_management::REFRESH_TYPE_CPU |
+                              task_management::REFRESH_TYPE_MEMORY |
+                                  task_management::REFRESH_TYPE_PRIORITY),
+      system_cpu_cores_range_(GetCurrentSystemCpuCoresRange()) {
+}
+
+// static
+scoped_ptr<rappor::Sample> ResourceReporter::CreateRapporSample(
+    rappor::RapporService* rappor_service,
+    const ResourceReporter::TaskRecord& task_record) {
+  scoped_ptr<rappor::Sample> sample(rappor_service->CreateSample(
+      rappor::UMA_RAPPOR_TYPE));
+  sample->SetStringField(kRapporTaskStringField,
+                         task_record.task_name_for_rappor);
+  sample->SetFlagsField(kRapporPriorityFlagsField,
+                        task_record.is_background ? BACKGROUND : FOREGROUND,
+                        PRIORITIES_NUM);
+  return sample.Pass();
+}
+
+// static
+ResourceReporter::CpuUsageRange
+ResourceReporter::GetCpuUsageRange(double cpu) {
+  if (cpu > 60.0)
+    return RANGE_ABOVE_60_PERCENT;
+  if (cpu > 30.0)
+    return RANGE_30_TO_60_PERCENT;
+  if (cpu > 10.0)
+    return RANGE_10_TO_30_PERCENT;
+
+  return RANGE_0_TO_10_PERCENT;
+}
+
+// static
+ResourceReporter::MemoryUsageRange
+ResourceReporter::GetMemoryUsageRange(int64_t memory_in_bytes) {
+  if (memory_in_bytes > kMemory1GB)
+    return RANGE_ABOVE_1_GB;
+  if (memory_in_bytes > kMemory800MB)
+    return RANGE_800_TO_1_GB;
+  if (memory_in_bytes > kMemory600MB)
+    return RANGE_600_TO_800_MB;
+  if (memory_in_bytes > kMemory400MB)
+      return RANGE_400_TO_600_MB;
+  if (memory_in_bytes > kMemory200MB)
+      return RANGE_200_TO_400_MB;
+
+  return RANGE_0_TO_200_MB;
+}
+
+// static
+ResourceReporter::CpuCoresNumberRange
+ResourceReporter::GetCurrentSystemCpuCoresRange() {
+  const int cpus = base::SysInfo::NumberOfProcessors();
+
+  if (cpus > 16)
+    return RANGE_CORES_ABOVE_16_CORES;
+  if (cpus > 8)
+    return RANGE_CORES_9_TO_16_CORES;
+  if (cpus > 4)
+    return RANGE_CORES_5_TO_8_CORES;
+  if (cpus > 2)
+    return RANGE_CORES_3_TO_4_CORES;
+  if (cpus == 2)
+    return RANGE_CORES_2_CORES;
+  if (cpus == 1)
+    return RANGE_CORES_1_CORE;
+
+  NOTREACHED();
+  return RANGE_CORES_NA;
+}
+
+bool ResourceReporter::ShouldRecordSamples() {
+  if (is_first_memory_pressure_event_) {
+    is_first_memory_pressure_event_ = false;
+    return true;
+  }
+
+  return (base::TimeTicks::Now() - last_memory_pressure_event_time_) >=
+      base::TimeDelta::FromMilliseconds(kMinimumTimeBetweenReportsInMS);
+}
+
+void ResourceReporter::OnMemoryPressure(
+    MemoryPressureLevel memory_pressure_level) {
+  if (memory_pressure_level >=
+      MemoryPressureLevel::MEMORY_PRESSURE_LEVEL_MODERATE) {
+    // Report browser and GPU processes usage using UMA histograms.
+    UMA_HISTOGRAM_ENUMERATION("ResourceReporter.BrowserProcess.CpuUsage",
+                              GetCpuUsageRange(last_browser_process_cpu_),
+                              CPU_RANGES_NUM);
+    UMA_HISTOGRAM_ENUMERATION("ResourceReporter.BrowserProcess.MemoryUsage",
+                              GetMemoryUsageRange(last_browser_process_memory_),
+                              MEMORY_RANGES_NUM);
+    UMA_HISTOGRAM_ENUMERATION("ResourceReporter.GpuProcess.CpuUsage",
+                              GetCpuUsageRange(last_gpu_process_cpu_),
+                              CPU_RANGES_NUM);
+    UMA_HISTOGRAM_ENUMERATION("ResourceReporter.GpuProcess.MemoryUsage",
+                              GetMemoryUsageRange(last_gpu_process_memory_),
+                              MEMORY_RANGES_NUM);
+
+    // For the rest of tasks, report them using Rappor.
+    auto rappor_service = g_browser_process->rappor_service();
+    if (! rappor_service)

[Steven Holte, 2015/11/17 23:42:04]

nit: whitespace?

[afakhry, 2015/11/18 01:06:51]

Done.

+      return;
+
+    if (!ShouldRecordSamples())
+      return;
+    last_memory_pressure_event_time_ = base::TimeTicks::Now();
+
+    // Use weighted random sampling to select a task to report in the CPU
+    // metric.
+    TaskRecord* sampled_task = nullptr;
+    int cpu_weights_sum = 0;
+    for (const auto& task_data : task_records_by_cpu_) {
+      if ((base::RandDouble() * (cpu_weights_sum + task_data->cpu_weight)) >=

[Steven Holte, 2015/11/17 23:42:04]

nit: Might be nice to move this to a helper function like SampleTaskByCpu

[afakhry, 2015/11/18 01:06:51]

Done.

+          cpu_weights_sum) {
+        sampled_task = task_data;
+      }
+      cpu_weights_sum += task_data->cpu_weight;
+    }
+
+    if (sampled_task) {
+      scoped_ptr<rappor::Sample> cpu_sample(CreateRapporSample(rappor_service,
+                                                               *sampled_task));
+      cpu_sample->SetFlagsField(kRapporNumCoresRangeFlagsField,
+                                system_cpu_cores_range_,
+                                CORES_RANGES_NUM);
+      cpu_sample->SetFlagsField(kRapporUsageRangeFlagsField,
+                                GetCpuUsageRange(sampled_task->cpu),
+                                CPU_RANGES_NUM);
+      rappor_service->RecordSampleObj(kCpuRapporMetric, cpu_sample.Pass());
+    }
+
+    // Use weighted random sampling to select a task to report in the memory
+    // metric.
+    sampled_task = nullptr;
+    int memory_weights_sum = 0;
+    for (const auto& task_data : task_records_by_memory_) {
+      if ((base::RandDouble() *
+           (memory_weights_sum + task_data->memory_weight)) >=
+            memory_weights_sum) {
+        sampled_task = task_data;
+      }
+      memory_weights_sum += task_data->memory_weight;
+    }
+
+    if (sampled_task) {
+      scoped_ptr<rappor::Sample> memory_sample(CreateRapporSample(
+          rappor_service, *sampled_task));
+      memory_sample->SetFlagsField(kRapporUsageRangeFlagsField,
+                                   GetMemoryUsageRange(sampled_task->memory),
+                                   MEMORY_RANGES_NUM);
+      rappor_service->RecordSampleObj(kMemoryRapporMetric,
+                                      memory_sample.Pass());
+    }
+  }
+}
+
+}  // namespace chromeos