xref: /openbmc/linux/fs/proc/stat.c (revision bc5aa3a0)
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/seq_file.h>
9 #include <linux/slab.h>
10 #include <linux/time.h>
11 #include <linux/irqnr.h>
12 #include <linux/cputime.h>
13 #include <linux/tick.h>
14 
15 #ifndef arch_irq_stat_cpu
16 #define arch_irq_stat_cpu(cpu) 0
17 #endif
18 #ifndef arch_irq_stat
19 #define arch_irq_stat() 0
20 #endif
21 
22 #ifdef arch_idle_time
23 
24 static cputime64_t get_idle_time(int cpu)
25 {
26 	cputime64_t idle;
27 
28 	idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
29 	if (cpu_online(cpu) && !nr_iowait_cpu(cpu))
30 		idle += arch_idle_time(cpu);
31 	return idle;
32 }
33 
34 static cputime64_t get_iowait_time(int cpu)
35 {
36 	cputime64_t iowait;
37 
38 	iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
39 	if (cpu_online(cpu) && nr_iowait_cpu(cpu))
40 		iowait += arch_idle_time(cpu);
41 	return iowait;
42 }
43 
44 #else
45 
46 static u64 get_idle_time(int cpu)
47 {
48 	u64 idle, idle_time = -1ULL;
49 
50 	if (cpu_online(cpu))
51 		idle_time = get_cpu_idle_time_us(cpu, NULL);
52 
53 	if (idle_time == -1ULL)
54 		/* !NO_HZ or cpu offline so we can rely on cpustat.idle */
55 		idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
56 	else
57 		idle = usecs_to_cputime64(idle_time);
58 
59 	return idle;
60 }
61 
62 static u64 get_iowait_time(int cpu)
63 {
64 	u64 iowait, iowait_time = -1ULL;
65 
66 	if (cpu_online(cpu))
67 		iowait_time = get_cpu_iowait_time_us(cpu, NULL);
68 
69 	if (iowait_time == -1ULL)
70 		/* !NO_HZ or cpu offline so we can rely on cpustat.iowait */
71 		iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
72 	else
73 		iowait = usecs_to_cputime64(iowait_time);
74 
75 	return iowait;
76 }
77 
78 #endif
79 
80 static int show_stat(struct seq_file *p, void *v)
81 {
82 	int i, j;
83 	u64 user, nice, system, idle, iowait, irq, softirq, steal;
84 	u64 guest, guest_nice;
85 	u64 sum = 0;
86 	u64 sum_softirq = 0;
87 	unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};
88 	struct timespec64 boottime;
89 
90 	user = nice = system = idle = iowait =
91 		irq = softirq = steal = 0;
92 	guest = guest_nice = 0;
93 	getboottime64(&boottime);
94 
95 	for_each_possible_cpu(i) {
96 		user += kcpustat_cpu(i).cpustat[CPUTIME_USER];
97 		nice += kcpustat_cpu(i).cpustat[CPUTIME_NICE];
98 		system += kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
99 		idle += get_idle_time(i);
100 		iowait += get_iowait_time(i);
101 		irq += kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
102 		softirq += kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ];
103 		steal += kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
104 		guest += kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
105 		guest_nice += kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
106 		sum += kstat_cpu_irqs_sum(i);
107 		sum += arch_irq_stat_cpu(i);
108 
109 		for (j = 0; j < NR_SOFTIRQS; j++) {
110 			unsigned int softirq_stat = kstat_softirqs_cpu(j, i);
111 
112 			per_softirq_sums[j] += softirq_stat;
113 			sum_softirq += softirq_stat;
114 		}
115 	}
116 	sum += arch_irq_stat();
117 
118 	seq_puts(p, "cpu ");
119 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(user));
120 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(nice));
121 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(system));
122 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(idle));
123 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(iowait));
124 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(irq));
125 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(softirq));
126 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(steal));
127 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest));
128 	seq_put_decimal_ull(p, ' ', cputime64_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, ' ', cputime64_to_clock_t(user));
145 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(nice));
146 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(system));
147 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(idle));
148 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(iowait));
149 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(irq));
150 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(softirq));
151 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(steal));
152 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest));
153 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest_nice));
154 		seq_putc(p, '\n');
155 	}
156 	seq_printf(p, "intr %llu", (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_printf(p, "softirq %llu", (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