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 "perfetto/base/time.h"
20 #include "perfetto/ext/base/file_utils.h"
21 #include "perfetto/ext/base/string_splitter.h"
22 #include "perfetto/ext/base/string_utils.h"
23
24 #include "protos/perfetto/trace/system_info/cpu_info.pbzero.h"
25 #include "protos/perfetto/trace/trace_packet.pbzero.h"
26
27 namespace perfetto {
28
29 namespace {
30
31 // Key for default processor string in /proc/cpuinfo as seen on arm. Note the
32 // uppercase P.
33 const char kDefaultProcessor[] = "Processor";
34
35 // Key for processor entry in /proc/cpuinfo. Used to determine whether a group
36 // of lines describes a CPU.
37 const char kProcessor[] = "processor";
38
39 } // namespace
40
41 // static
42 const ProbesDataSource::Descriptor SystemInfoDataSource::descriptor = {
43 /* name */ "linux.system_info",
44 /* flags */ Descriptor::kFlagsNone,
45 };
46
SystemInfoDataSource(TracingSessionID session_id,std::unique_ptr<TraceWriter> writer,std::unique_ptr<CpuFreqInfo> cpu_freq_info)47 SystemInfoDataSource::SystemInfoDataSource(
48 TracingSessionID session_id,
49 std::unique_ptr<TraceWriter> writer,
50 std::unique_ptr<CpuFreqInfo> cpu_freq_info)
51 : ProbesDataSource(session_id, &descriptor),
52 writer_(std::move(writer)),
53 cpu_freq_info_(std::move(cpu_freq_info)) {}
54
Start()55 void SystemInfoDataSource::Start() {
56 auto packet = writer_->NewTracePacket();
57 packet->set_timestamp(static_cast<uint64_t>(base::GetBootTimeNs().count()));
58 auto* cpu_info = packet->set_cpu_info();
59
60 // Parse /proc/cpuinfo which contains groups of "key\t: value" lines separated
61 // by an empty line. Each group represents a CPU. See the full example in the
62 // unittest.
63 std::string proc_cpu_info = ReadFile("/proc/cpuinfo");
64 std::string::iterator line_start = proc_cpu_info.begin();
65 std::string::iterator line_end = proc_cpu_info.end();
66 std::string default_processor = "unknown";
67 std::string cpu_index = "";
68 uint32_t next_cpu_index = 0;
69 while (line_start != proc_cpu_info.end()) {
70 line_end = find(line_start, proc_cpu_info.end(), '\n');
71 if (line_end == proc_cpu_info.end())
72 break;
73 std::string line = std::string(line_start, line_end);
74 line_start = line_end + 1;
75 if (line.empty() && !cpu_index.empty()) {
76 PERFETTO_DCHECK(cpu_index == std::to_string(next_cpu_index));
77 auto* cpu = cpu_info->add_cpus();
78 cpu->set_processor(default_processor);
79 auto freqs_range = cpu_freq_info_->GetFreqs(next_cpu_index);
80 for (auto it = freqs_range.first; it != freqs_range.second; it++) {
81 cpu->add_frequencies(*it);
82 }
83 cpu_index = "";
84 next_cpu_index++;
85 continue;
86 }
87 auto splits = base::SplitString(line, ":");
88 if (splits.size() != 2)
89 continue;
90 std::string key =
91 base::StripSuffix(base::StripChars(splits[0], "\t", ' '), " ");
92 std::string value = base::StripPrefix(splits[1], " ");
93 if (key == kDefaultProcessor)
94 default_processor = value;
95 else if (key == kProcessor)
96 cpu_index = value;
97 }
98
99 packet->Finalize();
100 writer_->Flush();
101 }
102
Flush(FlushRequestID,std::function<void ()> callback)103 void SystemInfoDataSource::Flush(FlushRequestID,
104 std::function<void()> callback) {
105 writer_->Flush(callback);
106 }
107
ReadFile(std::string path)108 std::string SystemInfoDataSource::ReadFile(std::string path) {
109 std::string contents;
110 if (!base::ReadFile(path, &contents))
111 return "";
112 return contents;
113 }
114
115 } // namespace perfetto
116