xref: /linux/fs/proc/stat.c (revision 87c34ed3aba9249cb06d1a1f100cd3618f29268c)
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 #ifndef arch_idle_time
22 #define arch_idle_time(cpu) 0
23 #endif
24 
25 static u64 get_idle_time(int cpu)
26 {
27 	u64 idle, idle_time = get_cpu_idle_time_us(cpu, NULL);
28 
29 	if (idle_time == -1ULL) {
30 		/* !NO_HZ so we can rely on cpustat.idle */
31 		idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
32 		idle += arch_idle_time(cpu);
33 	} else
34 		idle = usecs_to_cputime64(idle_time);
35 
36 	return idle;
37 }
38 
39 static u64 get_iowait_time(int cpu)
40 {
41 	u64 iowait, iowait_time = get_cpu_iowait_time_us(cpu, NULL);
42 
43 	if (iowait_time == -1ULL)
44 		/* !NO_HZ so we can rely on cpustat.iowait */
45 		iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
46 	else
47 		iowait = usecs_to_cputime64(iowait_time);
48 
49 	return iowait;
50 }
51 
52 static int show_stat(struct seq_file *p, void *v)
53 {
54 	int i, j;
55 	unsigned long jif;
56 	u64 user, nice, system, idle, iowait, irq, softirq, steal;
57 	u64 guest, guest_nice;
58 	u64 sum = 0;
59 	u64 sum_softirq = 0;
60 	unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};
61 	struct timespec boottime;
62 
63 	user = nice = system = idle = iowait =
64 		irq = softirq = steal = 0;
65 	guest = guest_nice = 0;
66 	getboottime(&boottime);
67 	jif = boottime.tv_sec;
68 
69 	for_each_possible_cpu(i) {
70 		user += kcpustat_cpu(i).cpustat[CPUTIME_USER];
71 		nice += kcpustat_cpu(i).cpustat[CPUTIME_NICE];
72 		system += kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
73 		idle += get_idle_time(i);
74 		iowait += get_iowait_time(i);
75 		irq += kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
76 		softirq += kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ];
77 		steal += kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
78 		guest += kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
79 		guest_nice += kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
80 		sum += kstat_cpu_irqs_sum(i);
81 		sum += arch_irq_stat_cpu(i);
82 
83 		for (j = 0; j < NR_SOFTIRQS; j++) {
84 			unsigned int softirq_stat = kstat_softirqs_cpu(j, i);
85 
86 			per_softirq_sums[j] += softirq_stat;
87 			sum_softirq += softirq_stat;
88 		}
89 	}
90 	sum += arch_irq_stat();
91 
92 	seq_puts(p, "cpu ");
93 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(user));
94 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(nice));
95 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(system));
96 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(idle));
97 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(iowait));
98 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(irq));
99 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(softirq));
100 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(steal));
101 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest));
102 	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest_nice));
103 	seq_putc(p, '\n');
104 
105 	for_each_online_cpu(i) {
106 		/* Copy values here to work around gcc-2.95.3, gcc-2.96 */
107 		user = kcpustat_cpu(i).cpustat[CPUTIME_USER];
108 		nice = kcpustat_cpu(i).cpustat[CPUTIME_NICE];
109 		system = kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
110 		idle = get_idle_time(i);
111 		iowait = get_iowait_time(i);
112 		irq = kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
113 		softirq = kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ];
114 		steal = kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
115 		guest = kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
116 		guest_nice = kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
117 		seq_printf(p, "cpu%d", i);
118 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(user));
119 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(nice));
120 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(system));
121 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(idle));
122 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(iowait));
123 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(irq));
124 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(softirq));
125 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(steal));
126 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest));
127 		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest_nice));
128 		seq_putc(p, '\n');
129 	}
130 	seq_printf(p, "intr %llu", (unsigned long long)sum);
131 
132 	/* sum again ? it could be updated? */
133 	for_each_irq_nr(j)
134 		seq_put_decimal_ull(p, ' ', kstat_irqs(j));
135 
136 	seq_printf(p,
137 		"\nctxt %llu\n"
138 		"btime %lu\n"
139 		"processes %lu\n"
140 		"procs_running %lu\n"
141 		"procs_blocked %lu\n",
142 		nr_context_switches(),
143 		(unsigned long)jif,
144 		total_forks,
145 		nr_running(),
146 		nr_iowait());
147 
148 	seq_printf(p, "softirq %llu", (unsigned long long)sum_softirq);
149 
150 	for (i = 0; i < NR_SOFTIRQS; i++)
151 		seq_put_decimal_ull(p, ' ', per_softirq_sums[i]);
152 	seq_putc(p, '\n');
153 
154 	return 0;
155 }
156 
157 static int stat_open(struct inode *inode, struct file *file)
158 {
159 	unsigned size = 1024 + 128 * num_possible_cpus();
160 	char *buf;
161 	struct seq_file *m;
162 	int res;
163 
164 	/* minimum size to display an interrupt count : 2 bytes */
165 	size += 2 * nr_irqs;
166 
167 	/* don't ask for more than the kmalloc() max size */
168 	if (size > KMALLOC_MAX_SIZE)
169 		size = KMALLOC_MAX_SIZE;
170 	buf = kmalloc(size, GFP_KERNEL);
171 	if (!buf)
172 		return -ENOMEM;
173 
174 	res = single_open(file, show_stat, NULL);
175 	if (!res) {
176 		m = file->private_data;
177 		m->buf = buf;
178 		m->size = ksize(buf);
179 	} else
180 		kfree(buf);
181 	return res;
182 }
183 
184 static const struct file_operations proc_stat_operations = {
185 	.open		= stat_open,
186 	.read		= seq_read,
187 	.llseek		= seq_lseek,
188 	.release	= single_release,
189 };
190 
191 static int __init proc_stat_init(void)
192 {
193 	proc_create("stat", 0, NULL, &proc_stat_operations);
194 	return 0;
195 }
196 module_init(proc_stat_init);
197