1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
|
// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "components/system_cpu/cpu_probe_win.h"
#include <optional>
#include <utility>
#include "base/cpu.h"
#include "base/logging.h"
#include "base/memory/ptr_util.h"
#include "base/memory/scoped_refptr.h"
#include "base/sequence_checker.h"
#include "base/task/sequenced_task_runner.h"
#include "base/task/task_traits.h"
#include "base/task/thread_pool.h"
#include "base/win/pdh_shim.h"
#include "base/win/scoped_pdh_query.h"
#include "components/system_cpu/cpu_sample.h"
namespace system_cpu {
namespace {
constexpr wchar_t kHypervisorLogicalProcessorCounter[] =
L"\\Hyper-V Hypervisor Logical Processor(_Total)\\% Total Run Time";
constexpr wchar_t kProcessorCounter[] =
L"\\Processor(_Total)\\% Processor Time";
} // namespace
// Helper class that performs the actual I/O. It must run on a
// SequencedTaskRunner that is properly configured for blocking I/O
// operations, and uses CONTINUE_ON_SHUTDOWN since Pdh functions can hang (see
// https://crbug.com/1499644). This means it must not use any globals that
// are deleted on browser shutdown.
class CpuProbeWin::BlockingTaskRunnerHelper final {
public:
BlockingTaskRunnerHelper();
~BlockingTaskRunnerHelper();
BlockingTaskRunnerHelper(const BlockingTaskRunnerHelper&) = delete;
BlockingTaskRunnerHelper& operator=(const BlockingTaskRunnerHelper&) = delete;
std::optional<CpuSample> Update();
private:
SEQUENCE_CHECKER(sequence_checker_);
// Used to derive CPU utilization.
base::win::ScopedPdhQuery cpu_query_ GUARDED_BY_CONTEXT(sequence_checker_);
// This "handle" doesn't need to be freed but its lifetime is associated
// with cpu_query_.
PDH_HCOUNTER cpu_percent_utilization_ GUARDED_BY_CONTEXT(sequence_checker_);
// True if PdhCollectQueryData has been called.
//
// It requires two data samples to calculate a formatted data value. So
// PdhCollectQueryData should be called twice before calling
// PdhGetFormattedCounterValue.
// Detailed information can be found in the following website:
// https://learn.microsoft.com/en-us/windows/win32/perfctrs/collecting-performance-data
bool got_baseline_ GUARDED_BY_CONTEXT(sequence_checker_) = false;
};
CpuProbeWin::BlockingTaskRunnerHelper::BlockingTaskRunnerHelper() = default;
CpuProbeWin::BlockingTaskRunnerHelper::~BlockingTaskRunnerHelper() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
}
std::optional<CpuSample> CpuProbeWin::BlockingTaskRunnerHelper::Update() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
PDH_STATUS pdh_status;
if (!cpu_query_.is_valid()) {
cpu_query_ = base::win::ScopedPdhQuery::Create();
if (!cpu_query_.is_valid()) {
return std::nullopt;
}
// When running in a VM, to provide a useful compute pressure signal, we
// must measure the usage of the physical CPU rather than the virtual CPU
// of the particular guest we are running in. The Microsoft documentation
// explains how to get this data when running under Hyper-V:
// https://learn.microsoft.com/en-us/windows-server/administration/performance-tuning/role/hyper-v-server/configuration#cpu-statistics
const bool is_running_in_vm = base::CPU().is_running_in_vm();
const auto* query_info = is_running_in_vm
? kHypervisorLogicalProcessorCounter
: kProcessorCounter;
pdh_status = PdhAddEnglishCounter(cpu_query_.get(), query_info, NULL,
&cpu_percent_utilization_);
// When Chrome is running under a different hypervisor, we can add the
// Hyper-V performance counter successfully but it isn't available to
// obtain data. Fall back to the normal one in this case.
if (is_running_in_vm && pdh_status == ERROR_SUCCESS) {
pdh_status = PdhCollectQueryData(cpu_query_.get());
if (pdh_status != ERROR_SUCCESS) {
query_info = kProcessorCounter;
pdh_status = PdhAddEnglishCounter(cpu_query_.get(), query_info, NULL,
&cpu_percent_utilization_);
}
}
if (pdh_status != ERROR_SUCCESS) {
cpu_query_.reset();
LOG(ERROR) << "PdhAddEnglishCounter failed for '" << query_info
<< "': " << logging::SystemErrorCodeToString(pdh_status);
return std::nullopt;
}
}
pdh_status = PdhCollectQueryData(cpu_query_.get());
if (pdh_status != ERROR_SUCCESS) {
LOG(ERROR) << "PdhCollectQueryData failed: "
<< logging::SystemErrorCodeToString(pdh_status);
return std::nullopt;
}
if (!got_baseline_) {
got_baseline_ = true;
return std::nullopt;
}
PDH_FMT_COUNTERVALUE counter_value;
pdh_status = PdhGetFormattedCounterValue(
cpu_percent_utilization_, PDH_FMT_DOUBLE, NULL, &counter_value);
if (pdh_status != ERROR_SUCCESS) {
LOG(ERROR) << "PdhGetFormattedCounterValue failed: "
<< logging::SystemErrorCodeToString(pdh_status);
return std::nullopt;
}
return CpuSample{counter_value.doubleValue / 100.0};
}
// static
std::unique_ptr<CpuProbeWin> CpuProbeWin::Create() {
return base::WrapUnique(new CpuProbeWin());
}
CpuProbeWin::CpuProbeWin() {
// BlockingTaskRunnerHelper makes heavy use of Pdh* functions than can load
// DLL's, which must happen in the foreground to avoid a priority inversion
// in the Windows DLL loader lock. Tasks on the helper sequence can be
// delayed (BEST_EFFORT priority) but once started must run in the foreground
// (MUST_USE_FOREGROUND policy) to avoid being descheduled while another
// foreground thread is waiting for the loader lock.
helper_ = base::SequenceBound<BlockingTaskRunnerHelper>(
base::ThreadPool::CreateSequencedTaskRunner(
{base::MayBlock(), base::TaskPriority::BEST_EFFORT,
base::ThreadPolicy::MUST_USE_FOREGROUND,
base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN}));
}
CpuProbeWin::~CpuProbeWin() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
}
void CpuProbeWin::Update(SampleCallback callback) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
helper_.AsyncCall(&BlockingTaskRunnerHelper::Update)
.Then(std::move(callback));
}
base::WeakPtr<CpuProbe> CpuProbeWin::GetWeakPtr() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
return weak_factory_.GetWeakPtr();
}
} // namespace system_cpu
|
