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
|
// Copyright (C) 2015-2017 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
#include "cpu_load_measurer.hpp"
#include <fstream>
#include <string>
#include <iostream>
#include <sstream>
#include <vector>
#include <stdexcept>
#include <cstdio>
#include <sys/types.h>
#include <unistd.h>
cpu_load_measurer::~cpu_load_measurer() {
}
cpu_load_measurer::cpu_load_measurer(std::uint32_t _pid) :
pid_(_pid),
jiffies_complete_start_(0),
jiffies_idle_start_(0),
jiffies_complete_stop_(0),
jiffies_idle_stop_(0),
clock_ticks_(0),
jiffies_passed_pid_start_(0),
jiffies_passed_pid_stop_(0),
cpu_load_pid_(0.0),
cpu_load_overall_(0.0),
cpu_load_pid_wo_idle_(0.0) {
}
void cpu_load_measurer::start() {
// reset everything
jiffies_complete_start_ = 0;
jiffies_idle_start_ = 0;
jiffies_complete_stop_ = 0;
jiffies_idle_stop_ = 0;
clock_ticks_ = 0;
jiffies_passed_pid_start_ = 0;
jiffies_passed_pid_stop_ = 0;
cpu_load_pid_= 0.0;
cpu_load_overall_ = 0.0;
cpu_load_pid_wo_idle_ = 0.0;
//start
jiffies_complete_start_ = read_proc_stat(&jiffies_idle_start_);
jiffies_passed_pid_start_ = read_proc_pid_stat();
}
void cpu_load_measurer::stop() {
jiffies_complete_stop_ = read_proc_stat(&jiffies_idle_stop_);
jiffies_passed_pid_stop_ = read_proc_pid_stat();
if(jiffies_complete_stop_ < jiffies_complete_start_ || jiffies_passed_pid_stop_ < jiffies_passed_pid_start_) {
std::cerr << "Overflow of values in procfs occured, can't calculate load" << std::endl;
exit(0);
}
cpu_load_pid_ = 100.0
* static_cast<double>(jiffies_passed_pid_stop_
- jiffies_passed_pid_start_)
/ static_cast<double>(jiffies_complete_stop_
- jiffies_complete_start_);
cpu_load_overall_ = 100.0
* static_cast<double>((jiffies_complete_stop_ - jiffies_idle_stop_)
- (jiffies_complete_start_ - jiffies_idle_start_))
/ static_cast<double>(jiffies_complete_stop_
- jiffies_complete_start_);
cpu_load_pid_wo_idle_ = 100.0
* static_cast<double>(jiffies_passed_pid_stop_
- jiffies_passed_pid_start_)
/ static_cast<double>((jiffies_complete_stop_ - jiffies_idle_stop_)
- (jiffies_complete_start_ - jiffies_idle_start_));
}
void cpu_load_measurer::print_cpu_load() const {
std::cout << "Used Jiffies complete: "
<< jiffies_complete_stop_ - jiffies_complete_start_ << " (worked: "
<< (jiffies_complete_stop_ - jiffies_idle_stop_)
- (jiffies_complete_start_ - jiffies_idle_start_)
<< " idled: " << jiffies_idle_stop_ - jiffies_idle_start_
<< ")" << std::endl;
std::cout << "Used Jiffies of pid " << pid_ << ": " << jiffies_passed_pid_stop_ - jiffies_passed_pid_start_ << std::endl;
std::cout << "Cpu load pid " << pid_ << " [%]: " << cpu_load_pid_ << std::endl;
std::cout << "Overall cpu load[%]: " << cpu_load_overall_ << std::endl;
std::cout << "Load caused by pid " << pid_ << " of overall cpu load [%]:" << cpu_load_pid_wo_idle_ << std::endl;
}
double cpu_load_measurer::get_cpu_load() const {
return cpu_load_pid_;
}
std::uint64_t cpu_load_measurer::read_proc_pid_stat() {
std::string path("/proc/" + std::to_string(pid_) + "/stat");
FILE* f = std::fopen(path.c_str(), "r");
if(!f) {
std::perror(std::string("Failed to open " + path).c_str());
exit(1);
}
// see Table 1-4 Contents of the stat files (as of 2.6.30-rc7)
// at https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/tree/Documentation/filesystems/proc.txt?id=refs/tags/v3.10.98
// and man proc (for conversion specifier)
std::uint64_t utime(0);
std::uint64_t stime(0);
std::int64_t cutime(0);
std::int64_t cstime(0);
if (std::fscanf(f, "%*d %*s %*c %*d %*d %*d %*d %*d %*u %*u %*u %*u %*u "
"%lu %lu %ld %ld", // utime, stime, cutime, cstime
&utime, &stime, &cutime, &cstime) == EOF) {
std::cerr << "Failed to read " + path << std::endl;
exit(1);
}
std::fclose(f);
return utime + stime + static_cast<std::uint64_t>(cutime) +
static_cast<std::uint64_t>(cstime);
}
std::uint64_t cpu_load_measurer::read_proc_stat(std::uint64_t* _idle) {
FILE* f = std::fopen("/proc/stat", "r");
if(!f) {
std::perror("Failed to open /proc/stat");
exit(1);
}
// see 1.8 Miscellaneous kernel statistics in /proc/stat
// at https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/tree/Documentation/filesystems/proc.txt?id=refs/tags/v3.10.98
std::uint64_t user(0);
std::uint64_t nice(0);
std::uint64_t system(0);
std::uint64_t idle(0);
std::uint64_t iowait(0);
std::uint64_t irq(0);
std::uint64_t softirq(0);
std::uint64_t steal(0);
std::uint64_t guest(0);
std::uint64_t guest_nice(0);
if (std::fscanf(f, "%*s %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu", &user,
&nice, &system, &idle, &iowait, &irq, &softirq, &steal, &guest,
&guest_nice) == EOF) {
std::cerr << "Failed to read /proc/stat" << std::endl;
exit(1);
}
std::fclose(f);
*_idle = idle;
return user + nice + system + idle + iowait + irq + softirq + steal + guest
+ guest_nice;
}
bool cpu_load_measurer::read_clock_ticks() {
long val(::sysconf(_SC_CLK_TCK));
if(val < 0 && errno == EINVAL) {
std::perror(__func__);
return false;
}
clock_ticks_ = static_cast<std::uint64_t>(val);
return true;
}
|
