121 lines
3.4 KiB
C++
121 lines
3.4 KiB
C++
// https://github.com/WojciechMula/toys/blob/master/000helpers/linux-perf-events.h
|
|
#pragma once
|
|
#ifdef __linux__
|
|
#ifdef __has_include
|
|
#if __has_include(<asm/unistd.h>)
|
|
#include <asm/unistd.h> // for __NR_perf_event_open
|
|
#else
|
|
#warning "Header asm/unistd.h cannot be found though it is a linux system. Are linux headers missing?"
|
|
#endif
|
|
#else // no __has_include
|
|
// Please insure that linux headers have been installed.
|
|
#include <asm/unistd.h> // for __NR_perf_event_open
|
|
#endif
|
|
#include <linux/perf_event.h> // for perf event constants
|
|
#include <sys/ioctl.h> // for ioctl
|
|
#include <unistd.h> // for syscall
|
|
|
|
#include <cerrno> // for errno
|
|
#include <cstring> // for std::memset
|
|
#include <stdexcept>
|
|
|
|
#include <iostream>
|
|
#include <vector>
|
|
|
|
template <int TYPE = PERF_TYPE_HARDWARE> class LinuxEvents {
|
|
int fd;
|
|
bool working;
|
|
perf_event_attr attribs{};
|
|
size_t num_events{};
|
|
std::vector<uint64_t> temp_result_vec{};
|
|
std::vector<uint64_t> result{};
|
|
std::vector<int> fds{};
|
|
bool quiet;
|
|
|
|
public:
|
|
explicit LinuxEvents(std::vector<int> config_vec, bool _quiet=false) : fd(0), working(true), quiet{_quiet} {
|
|
std::memset(&attribs, 0, sizeof(attribs));
|
|
attribs.type = TYPE;
|
|
attribs.size = sizeof(attribs);
|
|
attribs.disabled = 1;
|
|
attribs.exclude_kernel = 1;
|
|
attribs.exclude_hv = 1;
|
|
|
|
attribs.sample_period = 0;
|
|
attribs.read_format = PERF_FORMAT_GROUP | PERF_FORMAT_ID;
|
|
const int pid = 0; // the current process
|
|
const int cpu = -1; // all CPUs
|
|
const unsigned long flags = 0;
|
|
|
|
int group = -1; // no group
|
|
num_events = config_vec.size();
|
|
result.resize(config_vec.size());
|
|
uint32_t i = 0;
|
|
for (auto config : config_vec) {
|
|
attribs.config = config;
|
|
int _fd = static_cast<int>(syscall(__NR_perf_event_open, &attribs, pid, cpu, group, flags));
|
|
if (_fd == -1) {
|
|
report_error("perf_event_open");
|
|
}
|
|
fd = _fd; // fd tracks the last _fd value.
|
|
fds.push_back(fd);
|
|
ioctl(fd, PERF_EVENT_IOC_ID, &result[i++]);
|
|
if (group == -1) {
|
|
group = fd;
|
|
}
|
|
}
|
|
|
|
temp_result_vec.resize(num_events * 2 + 1);
|
|
}
|
|
|
|
~LinuxEvents() {
|
|
for (auto tfd : fds) {
|
|
if (tfd != -1) { close(tfd); }
|
|
}
|
|
}
|
|
|
|
inline void start() {
|
|
if (fd != -1) {
|
|
if (ioctl(fd, PERF_EVENT_IOC_RESET, PERF_IOC_FLAG_GROUP) == -1) {
|
|
report_error("ioctl(PERF_EVENT_IOC_RESET)");
|
|
}
|
|
|
|
if (ioctl(fd, PERF_EVENT_IOC_ENABLE, PERF_IOC_FLAG_GROUP) == -1) {
|
|
report_error("ioctl(PERF_EVENT_IOC_ENABLE)");
|
|
}
|
|
}
|
|
}
|
|
|
|
inline void end(std::vector<unsigned long long> &results) {
|
|
if (fd != -1) {
|
|
if (ioctl(fd, PERF_EVENT_IOC_DISABLE, PERF_IOC_FLAG_GROUP) == -1) {
|
|
report_error("ioctl(PERF_EVENT_IOC_DISABLE)");
|
|
}
|
|
|
|
if (read(fd, temp_result_vec.data(), temp_result_vec.size() * 8) == -1) {
|
|
report_error("read");
|
|
}
|
|
}
|
|
// our actual results are in slots 1,3,5, ... of this structure
|
|
// we really should be checking our result obtained earlier to be safe
|
|
for (uint32_t i = 1; i < temp_result_vec.size(); i += 2) {
|
|
results[i / 2] = temp_result_vec[i];
|
|
}
|
|
}
|
|
|
|
bool is_working() {
|
|
return working;
|
|
}
|
|
|
|
private:
|
|
void report_error(const std::string &context) {
|
|
if (!quiet) {
|
|
if (working) {
|
|
std::cerr << (context + ": " + std::string(strerror(errno))) << std::endl;
|
|
}
|
|
}
|
|
working = false;
|
|
}
|
|
};
|
|
#endif
|