blob: c28812d2b09359b3456e9b2839de197b0aa18adb [file] [log] [blame] [edit]
/*
* Copyright (C) 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <signal.h>
#include "perfetto/ext/base/file_utils.h"
#include "perfetto/ext/base/string_splitter.h"
#include "perfetto/ext/base/string_utils.h"
#include "perfetto/ext/base/string_writer.h"
#include "perfetto/ext/base/unix_task_runner.h"
#include "perfetto/ext/base/utils.h"
namespace perfetto {
namespace {
// This dumps the ftrace stats into trace marker every 500ms. This is useful for
// debugging overruns over time.
base::UnixTaskRunner* g_task_runner = nullptr;
uint32_t ExtractInt(const char* s) {
for (; *s != '\0'; s++) {
if (*s == ':') {
return static_cast<uint32_t>(atoi(s + 1));
}
}
return 0;
}
size_t NumberOfCpus() {
static size_t num_cpus = static_cast<size_t>(sysconf(_SC_NPROCESSORS_CONF));
return num_cpus;
}
std::string ReadFileIntoString(const std::string& path) {
// You can't seek or stat the procfs files on Android.
// The vast majority (884/886) of format files are under 4k.
std::string str;
str.reserve(4096);
if (!base::ReadFile(path, &str))
return "";
return str;
}
std::string ReadCpuStats(size_t cpu) {
std::string path =
"/sys/kernel/debug/tracing/per_cpu/cpu" + std::to_string(cpu) + "/stats";
return ReadFileIntoString(path);
}
void DumpAllCpuStats() {
base::ScopedFile file(
base::OpenFile("/sys/kernel/debug/tracing/trace_marker", O_RDWR));
if (!file) {
PERFETTO_ELOG("Unable to open trace marker file");
g_task_runner->PostDelayedTask(&DumpAllCpuStats, 500);
return;
}
for (uint32_t cpu = 0; cpu < NumberOfCpus(); cpu++) {
std::string text = ReadCpuStats(cpu);
if (text.empty())
continue;
char buffer[1024];
base::StringSplitter splitter(std::move(text), '\n');
while (splitter.Next()) {
base::StringWriter writer(buffer, base::ArraySize(buffer));
writer.AppendLiteral("C|");
writer.AppendInt(getpid());
writer.AppendLiteral("|");
if (base::StartsWith(splitter.cur_token(), "overrun")) {
writer.AppendLiteral("overrun_");
} else if (base::StartsWith(splitter.cur_token(), "commit overrun")) {
writer.AppendLiteral("commit_overrun_");
} else {
continue;
}
writer.AppendInt(cpu);
writer.AppendLiteral("|");
writer.AppendInt(ExtractInt(splitter.cur_token()));
writer.AppendLiteral("\n");
auto output = writer.GetStringView();
PERFETTO_CHECK(write(*file, output.data(), output.size()) ==
static_cast<ssize_t>(output.size()));
}
}
g_task_runner->PostDelayedTask(&DumpAllCpuStats, 500);
}
void SetupCtrlCHandler() {
// Setup signal handler.
struct sigaction sa {};
// Glibc headers for sa_sigaction trigger this.
#pragma GCC diagnostic push
#if defined(__clang__)
#pragma GCC diagnostic ignored "-Wdisabled-macro-expansion"
#endif
sa.sa_handler = [](int) { g_task_runner->Quit(); };
sa.sa_flags = static_cast<decltype(sa.sa_flags)>(SA_RESETHAND | SA_RESTART);
#pragma GCC diagnostic pop
sigaction(SIGINT, &sa, nullptr);
sigaction(SIGTERM, &sa, nullptr);
}
int DumpFtraceStatsMain() {
base::UnixTaskRunner task_runner;
g_task_runner = &task_runner;
SetupCtrlCHandler();
task_runner.PostTask(&DumpAllCpuStats);
task_runner.Run();
return 0;
}
} // namespace
} // namespace perfetto
int main(int argc, char** argv) {
perfetto::base::ignore_result(argc, argv);
return perfetto::DumpFtraceStatsMain();
}