xref: /openbmc/linux/fs/proc/stat.c (revision bb0eb050)
1 #include <linux/cpumask.h>
2 #include <linux/fs.h>
3 #include <linux/init.h>
4 #include <linux/interrupt.h>
5 #include <linux/kernel_stat.h>
6 #include <linux/proc_fs.h>
7 #include <linux/sched.h>
8 #include <linux/sched/stat.h>
9 #include <linux/seq_file.h>
10 #include <linux/slab.h>
11 #include <linux/time.h>
12 #include <linux/irqnr.h>
13 #include <linux/sched/cputime.h>
14 #include <linux/tick.h>
15 
16 #ifndef arch_irq_stat_cpu
17 #define arch_irq_stat_cpu(cpu) 0
18 #endif
19 #ifndef arch_irq_stat
20 #define arch_irq_stat() 0
21 #endif
22 
23 #ifdef arch_idle_time
24 
25 static u64 get_idle_time(int cpu)
26 {
27 	u64 idle;
28 
29 	idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
30 	if (cpu_online(cpu) && !nr_iowait_cpu(cpu))
31 		idle += arch_idle_time(cpu);
32 	return idle;
33 }
34 
35 static u64 get_iowait_time(int cpu)
36 {
37 	u64 iowait;
38 
39 	iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
40 	if (cpu_online(cpu) && nr_iowait_cpu(cpu))
41 		iowait += arch_idle_time(cpu);
42 	return iowait;
43 }
44 
45 #else
46 
47 static u64 get_idle_time(int cpu)
48 {
49 	u64 idle, idle_usecs = -1ULL;
50 
51 	if (cpu_online(cpu))
52 		idle_usecs = get_cpu_idle_time_us(cpu, NULL);
53 
54 	if (idle_usecs == -1ULL)
55 		/* !NO_HZ or cpu offline so we can rely on cpustat.idle */
56 		idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
57 	else
58 		idle = idle_usecs * NSEC_PER_USEC;
59 
60 	return idle;
61 }
62 
63 static u64 get_iowait_time(int cpu)
64 {
65 	u64 iowait, iowait_usecs = -1ULL;
66 
67 	if (cpu_online(cpu))
68 		iowait_usecs = get_cpu_iowait_time_us(cpu, NULL);
69 
70 	if (iowait_usecs == -1ULL)
71 		/* !NO_HZ or cpu offline so we can rely on cpustat.iowait */
72 		iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
73 	else
74 		iowait = iowait_usecs * NSEC_PER_USEC;
75 
76 	return iowait;
77 }
78 
79 #endif
80 
81 static int show_stat(struct seq_file *p, void *v)
82 {
83 	int i, j;
84 	u64 user, nice, system, idle, iowait, irq, softirq, steal;
85 	u64 guest, guest_nice;
86 	u64 sum = 0;
87 	u64 sum_softirq = 0;
88 	unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};
89 	struct timespec64 boottime;
90 
91 	user = nice = system = idle = iowait =
92 		irq = softirq = steal = 0;
93 	guest = guest_nice = 0;
94 	getboottime64(&boottime);
95 
96 	for_each_possible_cpu(i) {
97 		user += kcpustat_cpu(i).cpustat[CPUTIME_USER];
98 		nice += kcpustat_cpu(i).cpustat[CPUTIME_NICE];
99 		system += kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
100 		idle += get_idle_time(i);
101 		iowait += get_iowait_time(i);
102 		irq += kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
103 		softirq += kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ];
104 		steal += kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
105 		guest += kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
106 		guest_nice += kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
107 		sum += kstat_cpu_irqs_sum(i);
108 		sum += arch_irq_stat_cpu(i);
109 
110 		for (j = 0; j < NR_SOFTIRQS; j++) {
111 			unsigned int softirq_stat = kstat_softirqs_cpu(j, i);
112 
113 			per_softirq_sums[j] += softirq_stat;
114 			sum_softirq += softirq_stat;
115 		}
116 	}
117 	sum += arch_irq_stat();
118 
119 	seq_put_decimal_ull(p, "cpu  ", nsec_to_clock_t(user));
120 	seq_put_decimal_ull(p, " ", nsec_to_clock_t(nice));
121 	seq_put_decimal_ull(p, " ", nsec_to_clock_t(system));
122 	seq_put_decimal_ull(p, " ", nsec_to_clock_t(idle));
123 	seq_put_decimal_ull(p, " ", nsec_to_clock_t(iowait));
124 	seq_put_decimal_ull(p, " ", nsec_to_clock_t(irq));
125 	seq_put_decimal_ull(p, " ", nsec_to_clock_t(softirq));
126 	seq_put_decimal_ull(p, " ", nsec_to_clock_t(steal));
127 	seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest));
128 	seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest_nice));
129 	seq_putc(p, '\n');
130 
131 	for_each_online_cpu(i) {
132 		/* Copy values here to work around gcc-2.95.3, gcc-2.96 */
133 		user = kcpustat_cpu(i).cpustat[CPUTIME_USER];
134 		nice = kcpustat_cpu(i).cpustat[CPUTIME_NICE];
135 		system = kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
136 		idle = get_idle_time(i);
137 		iowait = get_iowait_time(i);
138 		irq = kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
139 		softirq = kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ];
140 		steal = kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
141 		guest = kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
142 		guest_nice = kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
143 		seq_printf(p, "cpu%d", i);
144 		seq_put_decimal_ull(p, " ", nsec_to_clock_t(user));
145 		seq_put_decimal_ull(p, " ", nsec_to_clock_t(nice));
146 		seq_put_decimal_ull(p, " ", nsec_to_clock_t(system));
147 		seq_put_decimal_ull(p, " ", nsec_to_clock_t(idle));
148 		seq_put_decimal_ull(p, " ", nsec_to_clock_t(iowait));
149 		seq_put_decimal_ull(p, " ", nsec_to_clock_t(irq));
150 		seq_put_decimal_ull(p, " ", nsec_to_clock_t(softirq));
151 		seq_put_decimal_ull(p, " ", nsec_to_clock_t(steal));
152 		seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest));
153 		seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest_nice));
154 		seq_putc(p, '\n');
155 	}
156 	seq_put_decimal_ull(p, "intr ", (unsigned long long)sum);
157 
158 	/* sum again ? it could be updated? */
159 	for_each_irq_nr(j)
160 		seq_put_decimal_ull(p, " ", kstat_irqs_usr(j));
161 
162 	seq_printf(p,
163 		"\nctxt %llu\n"
164 		"btime %llu\n"
165 		"processes %lu\n"
166 		"procs_running %lu\n"
167 		"procs_blocked %lu\n",
168 		nr_context_switches(),
169 		(unsigned long long)boottime.tv_sec,
170 		total_forks,
171 		nr_running(),
172 		nr_iowait());
173 
174 	seq_put_decimal_ull(p, "softirq ", (unsigned long long)sum_softirq);
175 
176 	for (i = 0; i < NR_SOFTIRQS; i++)
177 		seq_put_decimal_ull(p, " ", per_softirq_sums[i]);
178 	seq_putc(p, '\n');
179 
180 	return 0;
181 }
182 
183 static int stat_open(struct inode *inode, struct file *file)
184 {
185 	size_t size = 1024 + 128 * num_online_cpus();
186 
187 	/* minimum size to display an interrupt count : 2 bytes */
188 	size += 2 * nr_irqs;
189 	return single_open_size(file, show_stat, NULL, size);
190 }
191 
192 static const struct file_operations proc_stat_operations = {
193 	.open		= stat_open,
194 	.read		= seq_read,
195 	.llseek		= seq_lseek,
196 	.release	= single_release,
197 };
198 
199 static int __init proc_stat_init(void)
200 {
201 	proc_create("stat", 0, NULL, &proc_stat_operations);
202 	return 0;
203 }
204 fs_initcall(proc_stat_init);
205