1 // Copyright 2016 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "chromecast/browser/cast_system_memory_pressure_evaluator.h"
6
7 #include <algorithm>
8
9 #include "base/bind.h"
10 #include "base/command_line.h"
11 #include "base/location.h"
12 #include "base/logging.h"
13 #include "base/metrics/histogram_macros.h"
14 #include "base/process/process_metrics.h"
15 #include "base/single_thread_task_runner.h"
16 #include "base/strings/string_number_conversions.h"
17 #include "base/threading/thread_task_runner_handle.h"
18 #include "chromecast/base/chromecast_switches.h"
19 #include "chromecast/base/metrics/cast_metrics_helper.h"
20
21 #define MAKE_SURE_THREAD(callback, ...) \
22 if (!task_runner_->BelongsToCurrentThread()) { \
23 task_runner_->PostTask( \
24 FROM_HERE, \
25 base::BindOnce(&CastSystemMemoryPressureEvaluator::callback, \
26 weak_ptr_factory_.GetWeakPtr(), ##__VA_ARGS__)); \
27 return; \
28 }
29
30 namespace chromecast {
31 namespace {
32
33 // Memory thresholds (as fraction of total memory) for memory pressure levels.
34 // See more detailed description of pressure heuristic in PollPressureLevel.
35 // TODO(halliwell): tune thresholds based on data.
36 constexpr float kCriticalMemoryFraction = 0.25f;
37 constexpr float kModerateMemoryFraction = 0.4f;
38
39 // Default Relaxed memory thresholds selectively applied to a few apps.
40 constexpr float kRelaxedCriticalMemoryFraction = 0.1f;
41 constexpr float kRelaxedModerateMemoryFraction = 0.2f;
42
43 // Memory thresholds in MB for the simple heuristic based on 'free' memory.
44 constexpr int kCriticalFreeMemoryKB = 20 * 1024;
45 constexpr int kModerateFreeMemoryKB = 30 * 1024;
46
47 constexpr int kPollingIntervalMS = 5000;
48
GetSystemReservedKb()49 int GetSystemReservedKb() {
50 int rtn_kb_ = 0;
51 const base::CommandLine* command_line(base::CommandLine::ForCurrentProcess());
52 base::StringToInt(
53 command_line->GetSwitchValueASCII(switches::kMemPressureSystemReservedKb),
54 &rtn_kb_);
55 DCHECK(rtn_kb_ >= 0);
56 return std::max(rtn_kb_, 0);
57 }
58
59 } // namespace
60
CastSystemMemoryPressureEvaluator(std::unique_ptr<util::MemoryPressureVoter> voter)61 CastSystemMemoryPressureEvaluator::CastSystemMemoryPressureEvaluator(
62 std::unique_ptr<util::MemoryPressureVoter> voter)
63 : util::SystemMemoryPressureEvaluator(std::move(voter)),
64 critical_memory_fraction_command_line_(
65 GetSwitchValueDouble(switches::kCastMemoryPressureCriticalFraction,
66 -1.0f)),
67 moderate_memory_fraction_command_line_(
68 GetSwitchValueDouble(switches::kCastMemoryPressureModerateFraction,
69 -1.0f)),
70 system_reserved_kb_(GetSystemReservedKb()),
71 task_runner_(base::ThreadTaskRunnerHandle::Get()),
72 weak_ptr_factory_(this) {
73 relaxed_critical_memory_fraction_ = kRelaxedCriticalMemoryFraction;
74 relaxed_moderate_memory_fraction_ = kRelaxedModerateMemoryFraction;
75 critical_memory_fraction_ = critical_memory_fraction_command_line_;
76 moderate_memory_fraction_ = moderate_memory_fraction_command_line_;
77 // If the fractions from command line parameters are invalid they are subject
78 // to adjustment.
79 AdjustMemoryFractions(false);
80 PollPressureLevel();
81 }
82
83 CastSystemMemoryPressureEvaluator::~CastSystemMemoryPressureEvaluator() =
84 default;
85
PollPressureLevel()86 void CastSystemMemoryPressureEvaluator::PollPressureLevel() {
87 DCHECK(task_runner_->BelongsToCurrentThread());
88 base::MemoryPressureListener::MemoryPressureLevel level =
89 base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE;
90
91 base::SystemMemoryInfoKB info;
92 if (!base::GetSystemMemoryInfo(&info)) {
93 LOG(ERROR) << "GetSystemMemoryInfo failed";
94 } else if (system_reserved_kb_ != 0 || info.available != 0) {
95 // Preferred memory pressure heuristic:
96 // 1. Use /proc/meminfo's MemAvailable if possible, fall back to estimate
97 // of free + buffers + cached otherwise.
98 const int total_available = (info.available != 0)
99 ? info.available
100 : (info.free + info.buffers + info.cached);
101
102 // 2. Allow some memory to be 'reserved' on command line.
103 const int available = total_available - system_reserved_kb_;
104 const int total = info.total - system_reserved_kb_;
105 DCHECK_GT(total, 0);
106 const float ratio = available / static_cast<float>(total);
107
108 if (ratio < critical_memory_fraction_)
109 level = base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL;
110 else if (ratio < moderate_memory_fraction_)
111 level = base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_MODERATE;
112 } else {
113 // Backup method purely using 'free' memory. It may generate more
114 // pressure events than necessary, since more memory may actually be free.
115 if (info.free < kCriticalFreeMemoryKB)
116 level = base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL;
117 else if (info.free < kModerateFreeMemoryKB)
118 level = base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_MODERATE;
119 }
120
121 UpdateMemoryPressureLevel(level);
122
123 UMA_HISTOGRAM_PERCENTAGE("Platform.MeminfoMemFree",
124 (info.free * 100.0) / info.total);
125 UMA_HISTOGRAM_CUSTOM_COUNTS("Platform.Cast.MeminfoMemFreeDerived2",
126 (info.free + info.buffers + info.cached) / 1024,
127 1, 2000, 100);
128 if (info.available != 0) {
129 UMA_HISTOGRAM_CUSTOM_COUNTS("Platform.Cast.MeminfoMemAvailable2",
130 info.available / 1024, 1, 2000, 100);
131 }
132
133 task_runner_->PostDelayedTask(
134 FROM_HERE,
135 base::BindOnce(&CastSystemMemoryPressureEvaluator::PollPressureLevel,
136 weak_ptr_factory_.GetWeakPtr()),
137 base::TimeDelta::FromMilliseconds(kPollingIntervalMS));
138 }
139
UpdateMemoryPressureLevel(base::MemoryPressureListener::MemoryPressureLevel new_level)140 void CastSystemMemoryPressureEvaluator::UpdateMemoryPressureLevel(
141 base::MemoryPressureListener::MemoryPressureLevel new_level) {
142 DCHECK(task_runner_->BelongsToCurrentThread());
143 auto old_vote = current_vote();
144 SetCurrentVote(new_level);
145
146 SendCurrentVote(/* notify = */ current_vote() !=
147 base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE);
148
149 if (old_vote == current_vote())
150 return;
151
152 metrics::CastMetricsHelper::GetInstance()->RecordApplicationEventWithValue(
153 "Memory.Pressure.LevelChange", new_level);
154 }
155
AdjustMemoryFractions(bool relax)156 void CastSystemMemoryPressureEvaluator::AdjustMemoryFractions(bool relax) {
157 DCHECK(task_runner_->BelongsToCurrentThread());
158
159 if (critical_memory_fraction_command_line_ < 0) {
160 critical_memory_fraction_ =
161 relax ? relaxed_critical_memory_fraction_ : kCriticalMemoryFraction;
162 }
163 if (moderate_memory_fraction_command_line_ < 0) {
164 moderate_memory_fraction_ =
165 relax ? relaxed_moderate_memory_fraction_ : kModerateMemoryFraction;
166 }
167 LOG(INFO) << __func__
168 << ": critical_memory_fraction_=" << critical_memory_fraction_
169 << ", moderate_memory_fraction_=" << moderate_memory_fraction_;
170 }
171
ConfigRelaxMemoryPressureThresholds(float relaxed_critical_memory_fraction,float relaxed_moderate_memory_fraction)172 void CastSystemMemoryPressureEvaluator::ConfigRelaxMemoryPressureThresholds(
173 float relaxed_critical_memory_fraction,
174 float relaxed_moderate_memory_fraction) {
175 MAKE_SURE_THREAD(ConfigRelaxMemoryPressureThresholds,
176 relaxed_critical_memory_fraction,
177 relaxed_moderate_memory_fraction);
178
179 LOG(INFO) << __func__ << ", " << relaxed_critical_memory_fraction << ", "
180 << relaxed_moderate_memory_fraction;
181
182 if (relaxed_critical_memory_fraction > 0) {
183 relaxed_critical_memory_fraction_ = relaxed_critical_memory_fraction;
184 }
185 if (relaxed_moderate_memory_fraction > 0) {
186 relaxed_moderate_memory_fraction_ = relaxed_moderate_memory_fraction;
187 }
188 }
189
RelaxMemoryPressureThresholds(std::string requesting_app_session_id)190 void CastSystemMemoryPressureEvaluator::RelaxMemoryPressureThresholds(
191 std::string requesting_app_session_id) {
192 MAKE_SURE_THREAD(RelaxMemoryPressureThresholds,
193 std::move(requesting_app_session_id));
194 apps_needing_relaxed_memory_pressure_thresholds_.insert(
195 std::move(requesting_app_session_id));
196 AdjustMemoryFractions(true);
197 }
RestoreMemoryPressureThresholds(const std::string & requesting_app_session_id)198 void CastSystemMemoryPressureEvaluator::RestoreMemoryPressureThresholds(
199 const std::string& requesting_app_session_id) {
200 MAKE_SURE_THREAD(RestoreMemoryPressureThresholds, requesting_app_session_id);
201 apps_needing_relaxed_memory_pressure_thresholds_.erase(
202 requesting_app_session_id);
203 if (apps_needing_relaxed_memory_pressure_thresholds_.empty()) {
204 AdjustMemoryFractions(false);
205 }
206 }
207
208 } // namespace chromecast
209