xref: /openbmc/linux/fs/proc/stat.c (revision 95e9fd10)
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 <asm/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 = get_cpu_idle_time_us(cpu, NULL);
49 
50 	if (idle_time == -1ULL)
51 		/* !NO_HZ so we can rely on cpustat.idle */
52 		idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
53 	else
54 		idle = usecs_to_cputime64(idle_time);
55 
56 	return idle;
57 }
58 
59 static u64 get_iowait_time(int cpu)
60 {
61 	u64 iowait, iowait_time = get_cpu_iowait_time_us(cpu, NULL);
62 
63 	if (iowait_time == -1ULL)
64 		/* !NO_HZ so we can rely on cpustat.iowait */
65 		iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
66 	else
67 		iowait = usecs_to_cputime64(iowait_time);
68 
69 	return iowait;
70 }
71 
72 #endif
73 
74 static int show_stat(struct seq_file *p, void *v)
75 {
76 	int i, j;
77 	unsigned long jif;
78 	u64 user, nice, system, idle, iowait, irq, softirq, steal;
79 	u64 guest, guest_nice;
80 	u64 sum = 0;
81 	u64 sum_softirq = 0;
82 	unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};
83 	struct timespec boottime;
84 
85 	user = nice = system = idle = iowait =
86 		irq = softirq = steal = 0;
87 	guest = guest_nice = 0;
88 	getboottime(&boottime);
89 	jif = boottime.tv_sec;
90 
91 	for_each_possible_cpu(i) {
92 		user += kcpustat_cpu(i).cpustat[CPUTIME_USER];
93 		nice += kcpustat_cpu(i).cpustat[CPUTIME_NICE];
94 		system += kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
95 		idle += get_idle_time(i);
96 		iowait += get_iowait_time(i);
97 		irq += kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
98 		softirq += kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ];
99 		steal += kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
100 		guest += kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
101 		guest_nice += kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
102 		sum += kstat_cpu_irqs_sum(i);
103 		sum += arch_irq_stat_cpu(i);
104 
105 		for (j = 0; j < NR_SOFTIRQS; j++) {
106 			unsigned int softirq_stat = kstat_softirqs_cpu(j, i);
107 
108 			per_softirq_sums[j] += softirq_stat;
109 			sum_softirq += softirq_stat;
110 		}
111 	}
112 	sum += arch_irq_stat();
113 
114 	seq_puts(p, "cpu ");
115 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(user));
116 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(nice));
117 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(system));
118 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(idle));
119 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(iowait));
120 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(irq));
121 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(softirq));
122 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(steal));
123 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest));
124 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest_nice));
125 	seq_putc(p, '\n');
126 
127 	for_each_online_cpu(i) {
128 		/* Copy values here to work around gcc-2.95.3, gcc-2.96 */
129 		user = kcpustat_cpu(i).cpustat[CPUTIME_USER];
130 		nice = kcpustat_cpu(i).cpustat[CPUTIME_NICE];
131 		system = kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
132 		idle = get_idle_time(i);
133 		iowait = get_iowait_time(i);
134 		irq = kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
135 		softirq = kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ];
136 		steal = kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
137 		guest = kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
138 		guest_nice = kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
139 		seq_printf(p, "cpu%d", i);
140 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(user));
141 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(nice));
142 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(system));
143 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(idle));
144 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(iowait));
145 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(irq));
146 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(softirq));
147 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(steal));
148 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest));
149 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest_nice));
150 		seq_putc(p, '\n');
151 	}
152 	seq_printf(p, "intr %llu", (unsigned long long)sum);
153 
154 	/* sum again ? it could be updated? */
155 	for_each_irq_nr(j)
156 		seq_put_decimal_ull(p, ' ', kstat_irqs(j));
157 
158 	seq_printf(p,
159 		"\nctxt %llu\n"
160 		"btime %lu\n"
161 		"processes %lu\n"
162 		"procs_running %lu\n"
163 		"procs_blocked %lu\n",
164 		nr_context_switches(),
165 		(unsigned long)jif,
166 		total_forks,
167 		nr_running(),
168 		nr_iowait());
169 
170 	seq_printf(p, "softirq %llu", (unsigned long long)sum_softirq);
171 
172 	for (i = 0; i < NR_SOFTIRQS; i++)
173 		seq_put_decimal_ull(p, ' ', per_softirq_sums[i]);
174 	seq_putc(p, '\n');
175 
176 	return 0;
177 }
178 
179 static int stat_open(struct inode *inode, struct file *file)
180 {
181 	unsigned size = 1024 + 128 * num_possible_cpus();
182 	char *buf;
183 	struct seq_file *m;
184 	int res;
185 
186 	/* minimum size to display an interrupt count : 2 bytes */
187 	size += 2 * nr_irqs;
188 
189 	/* don't ask for more than the kmalloc() max size */
190 	if (size > KMALLOC_MAX_SIZE)
191 		size = KMALLOC_MAX_SIZE;
192 	buf = kmalloc(size, GFP_KERNEL);
193 	if (!buf)
194 		return -ENOMEM;
195 
196 	res = single_open(file, show_stat, NULL);
197 	if (!res) {
198 		m = file->private_data;
199 		m->buf = buf;
200 		m->size = ksize(buf);
201 	} else
202 		kfree(buf);
203 	return res;
204 }
205 
206 static const struct file_operations proc_stat_operations = {
207 	.open		= stat_open,
208 	.read		= seq_read,
209 	.llseek		= seq_lseek,
210 	.release	= single_release,
211 };
212 
213 static int __init proc_stat_init(void)
214 {
215 	proc_create("stat", 0, NULL, &proc_stat_operations);
216 	return 0;
217 }
218 module_init(proc_stat_init);
219