1 /*
2 * Copyright (C) 2020 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "src/traced/probes/system_info/system_info_data_source.h"
18
19 #include <optional>
20
21 #include "perfetto/base/logging.h"
22 #include "perfetto/base/time.h"
23 #include "perfetto/ext/base/file_utils.h"
24 #include "perfetto/ext/base/string_splitter.h"
25 #include "perfetto/ext/base/string_utils.h"
26 #include "src/traced/probes/system_info/cpu_info_features_allowlist.h"
27
28 #include "protos/perfetto/trace/system_info/cpu_info.pbzero.h"
29 #include "protos/perfetto/trace/trace_packet.pbzero.h"
30
31 namespace perfetto {
32
33 namespace {
34
35 // Key for default processor string in /proc/cpuinfo as seen on arm. Note the
36 // uppercase P.
37 const char kDefaultProcessor[] = "Processor";
38
39 // Key for processor entry in /proc/cpuinfo. Used to determine whether a group
40 // of lines describes a CPU.
41 const char kProcessor[] = "processor";
42
43 // Key for CPU implementer in /proc/cpuinfo. Arm only.
44 const char kImplementer[] = "CPU implementer";
45
46 // Key for CPU architecture in /proc/cpuinfo. Arm only.
47 const char kArchitecture[] = "CPU architecture";
48
49 // Key for CPU variant in /proc/cpuinfo. Arm only.
50 const char kVariant[] = "CPU variant";
51
52 // Key for CPU part in /proc/cpuinfo. Arm only.
53 const char kPart[] = "CPU part";
54
55 // Key for CPU revision in /proc/cpuinfo. Arm only.
56 const char kRevision[] = "CPU revision";
57
58 // Key for feature flags in /proc/cpuinfo. Arm calls them Features,
59 // Intel calls them Flags.
60 const char kFeatures[] = "Features";
61 const char kFlags[] = "Flags";
62
63 } // namespace
64
65 // static
66 const ProbesDataSource::Descriptor SystemInfoDataSource::descriptor = {
67 /* name */ "linux.system_info",
68 /* flags */ Descriptor::kFlagsNone,
69 /* fill_descriptor_func */ nullptr,
70 };
71
SystemInfoDataSource(TracingSessionID session_id,std::unique_ptr<TraceWriter> writer,std::unique_ptr<CpuFreqInfo> cpu_freq_info)72 SystemInfoDataSource::SystemInfoDataSource(
73 TracingSessionID session_id,
74 std::unique_ptr<TraceWriter> writer,
75 std::unique_ptr<CpuFreqInfo> cpu_freq_info)
76 : ProbesDataSource(session_id, &descriptor),
77 writer_(std::move(writer)),
78 cpu_freq_info_(std::move(cpu_freq_info)) {}
79
Start()80 void SystemInfoDataSource::Start() {
81 auto packet = writer_->NewTracePacket();
82 packet->set_timestamp(static_cast<uint64_t>(base::GetBootTimeNs().count()));
83 auto* cpu_info = packet->set_cpu_info();
84
85 // Parse /proc/cpuinfo which contains groups of "key\t: value" lines separated
86 // by an empty line. Each group represents a CPU. See the full example in the
87 // unittest.
88 std::string proc_cpu_info = ReadFile("/proc/cpuinfo");
89 std::string::iterator line_start = proc_cpu_info.begin();
90 std::string::iterator line_end = proc_cpu_info.end();
91 std::string default_processor = "unknown";
92 std::string cpu_index = "";
93
94 std::optional<uint32_t> implementer;
95 std::optional<uint32_t> architecture;
96 std::optional<uint32_t> variant;
97 std::optional<uint32_t> part;
98 std::optional<uint32_t> revision;
99 uint64_t features = 0;
100
101 uint32_t next_cpu_index = 0;
102 while (line_start != proc_cpu_info.end()) {
103 line_end = find(line_start, proc_cpu_info.end(), '\n');
104 if (line_end == proc_cpu_info.end())
105 break;
106 std::string line = std::string(line_start, line_end);
107 line_start = line_end + 1;
108 if (line.empty() && !cpu_index.empty()) {
109 PERFETTO_DCHECK(cpu_index == std::to_string(next_cpu_index));
110
111 auto* cpu = cpu_info->add_cpus();
112 cpu->set_processor(default_processor);
113
114 std::optional<uint32_t> cpu_capacity = base::StringToUInt32(
115 base::StripSuffix(ReadFile("/sys/devices/system/cpu/cpu" + cpu_index +
116 "/cpu_capacity"),
117 "\n"));
118
119 if (cpu_capacity.has_value()) {
120 cpu->set_capacity(cpu_capacity.value());
121 }
122
123 auto freqs_range = cpu_freq_info_->GetFreqs(next_cpu_index);
124 for (auto it = freqs_range.first; it != freqs_range.second; it++) {
125 cpu->add_frequencies(*it);
126 }
127 cpu_index = "";
128
129 // Set Arm CPU identifier if available
130 if (implementer && architecture && part && variant && revision) {
131 auto* identifier = cpu->set_arm_identifier();
132 identifier->set_implementer(implementer.value());
133 identifier->set_architecture(architecture.value());
134 identifier->set_variant(variant.value());
135 identifier->set_part(part.value());
136 identifier->set_revision(revision.value());
137 } else if (implementer || architecture || part || variant || revision) {
138 PERFETTO_ILOG("Failed to parse Arm specific fields from /proc/cpuinfo");
139 }
140
141 if (features != 0) {
142 cpu->set_features(features);
143 }
144
145 implementer = std::nullopt;
146 architecture = std::nullopt;
147 variant = std::nullopt;
148 part = std::nullopt;
149 revision = std::nullopt;
150 features = 0;
151
152 next_cpu_index++;
153 continue;
154 }
155 auto splits = base::SplitString(line, ":");
156 if (splits.size() != 2)
157 continue;
158 std::string key =
159 base::StripSuffix(base::StripChars(splits[0], "\t", ' '), " ");
160 std::string value = base::StripPrefix(splits[1], " ");
161 if (key == kDefaultProcessor) {
162 default_processor = value;
163 } else if (key == kProcessor) {
164 cpu_index = value;
165 } else if (key == kImplementer) {
166 implementer = base::CStringToUInt32(value.data(), 16);
167 } else if (key == kArchitecture) {
168 architecture = base::CStringToUInt32(value.data(), 10);
169 } else if (key == kVariant) {
170 variant = base::CStringToUInt32(value.data(), 16);
171 } else if (key == kPart) {
172 part = base::CStringToUInt32(value.data(), 16);
173 } else if (key == kRevision) {
174 revision = base::CStringToUInt32(value.data(), 10);
175 } else if (key == kFeatures || key == kFlags) {
176 for (base::StringSplitter ss(value.data(), ' '); ss.Next();) {
177 for (size_t i = 0; i < base::ArraySize(kCpuInfoFeatures); ++i) {
178 if (strcmp(ss.cur_token(), kCpuInfoFeatures[i]) == 0) {
179 static_assert(base::ArraySize(kCpuInfoFeatures) < 64);
180 features |= 1 << i;
181 }
182 }
183 }
184 }
185 }
186
187 packet->Finalize();
188 writer_->Flush();
189 }
190
Flush(FlushRequestID,std::function<void ()> callback)191 void SystemInfoDataSource::Flush(FlushRequestID,
192 std::function<void()> callback) {
193 writer_->Flush(callback);
194 }
195
ReadFile(std::string path)196 std::string SystemInfoDataSource::ReadFile(std::string path) {
197 std::string contents;
198 if (!base::ReadFile(path, &contents))
199 return "";
200 return contents;
201 }
202
203 } // namespace perfetto
204