xref: /linux/fs/proc/stat.c (revision 90ab5ee94171b3e28de6bb42ee30b527014e0be7)
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 
81 		for (j = 0; j < NR_SOFTIRQS; j++) {
82 			unsigned int softirq_stat = kstat_softirqs_cpu(j, i);
83 
84 			per_softirq_sums[j] += softirq_stat;
85 			sum_softirq += softirq_stat;
86 		}
87 	}
88 	sum += arch_irq_stat();
89 
90 	seq_printf(p, "cpu  %llu %llu %llu %llu %llu %llu %llu %llu %llu "
91 		"%llu\n",
92 		(unsigned long long)cputime64_to_clock_t(user),
93 		(unsigned long long)cputime64_to_clock_t(nice),
94 		(unsigned long long)cputime64_to_clock_t(system),
95 		(unsigned long long)cputime64_to_clock_t(idle),
96 		(unsigned long long)cputime64_to_clock_t(iowait),
97 		(unsigned long long)cputime64_to_clock_t(irq),
98 		(unsigned long long)cputime64_to_clock_t(softirq),
99 		(unsigned long long)cputime64_to_clock_t(steal),
100 		(unsigned long long)cputime64_to_clock_t(guest),
101 		(unsigned long long)cputime64_to_clock_t(guest_nice));
102 	for_each_online_cpu(i) {
103 		/* Copy values here to work around gcc-2.95.3, gcc-2.96 */
104 		user = kcpustat_cpu(i).cpustat[CPUTIME_USER];
105 		nice = kcpustat_cpu(i).cpustat[CPUTIME_NICE];
106 		system = kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
107 		idle = get_idle_time(i);
108 		iowait = get_iowait_time(i);
109 		irq = kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
110 		softirq = kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ];
111 		steal = kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
112 		guest = kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
113 		guest_nice = kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
114 		seq_printf(p,
115 			"cpu%d %llu %llu %llu %llu %llu %llu %llu %llu %llu "
116 			"%llu\n",
117 			i,
118 			(unsigned long long)cputime64_to_clock_t(user),
119 			(unsigned long long)cputime64_to_clock_t(nice),
120 			(unsigned long long)cputime64_to_clock_t(system),
121 			(unsigned long long)cputime64_to_clock_t(idle),
122 			(unsigned long long)cputime64_to_clock_t(iowait),
123 			(unsigned long long)cputime64_to_clock_t(irq),
124 			(unsigned long long)cputime64_to_clock_t(softirq),
125 			(unsigned long long)cputime64_to_clock_t(steal),
126 			(unsigned long long)cputime64_to_clock_t(guest),
127 			(unsigned long long)cputime64_to_clock_t(guest_nice));
128 	}
129 	seq_printf(p, "intr %llu", (unsigned long long)sum);
130 
131 	/* sum again ? it could be updated? */
132 	for_each_irq_nr(j)
133 		seq_printf(p, " %u", kstat_irqs(j));
134 
135 	seq_printf(p,
136 		"\nctxt %llu\n"
137 		"btime %lu\n"
138 		"processes %lu\n"
139 		"procs_running %lu\n"
140 		"procs_blocked %lu\n",
141 		nr_context_switches(),
142 		(unsigned long)jif,
143 		total_forks,
144 		nr_running(),
145 		nr_iowait());
146 
147 	seq_printf(p, "softirq %llu", (unsigned long long)sum_softirq);
148 
149 	for (i = 0; i < NR_SOFTIRQS; i++)
150 		seq_printf(p, " %u", per_softirq_sums[i]);
151 	seq_putc(p, '\n');
152 
153 	return 0;
154 }
155 
156 static int stat_open(struct inode *inode, struct file *file)
157 {
158 	unsigned size = 4096 * (1 + num_possible_cpus() / 32);
159 	char *buf;
160 	struct seq_file *m;
161 	int res;
162 
163 	/* don't ask for more than the kmalloc() max size */
164 	if (size > KMALLOC_MAX_SIZE)
165 		size = KMALLOC_MAX_SIZE;
166 	buf = kmalloc(size, GFP_KERNEL);
167 	if (!buf)
168 		return -ENOMEM;
169 
170 	res = single_open(file, show_stat, NULL);
171 	if (!res) {
172 		m = file->private_data;
173 		m->buf = buf;
174 		m->size = size;
175 	} else
176 		kfree(buf);
177 	return res;
178 }
179 
180 static const struct file_operations proc_stat_operations = {
181 	.open		= stat_open,
182 	.read		= seq_read,
183 	.llseek		= seq_lseek,
184 	.release	= single_release,
185 };
186 
187 static int __init proc_stat_init(void)
188 {
189 	proc_create("stat", 0, NULL, &proc_stat_operations);
190 	return 0;
191 }
192 module_init(proc_stat_init);
193