xref: /openbmc/linux/fs/proc/stat.c (revision 615c36f5)
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 cputime64_t get_idle_time(int cpu)
26 {
27 	u64 idle_time = get_cpu_idle_time_us(cpu, NULL);
28 	cputime64_t idle;
29 
30 	if (idle_time == -1ULL) {
31 		/* !NO_HZ so we can rely on cpustat.idle */
32 		idle = kstat_cpu(cpu).cpustat.idle;
33 		idle = cputime64_add(idle, arch_idle_time(cpu));
34 	} else
35 		idle = usecs_to_cputime(idle_time);
36 
37 	return idle;
38 }
39 
40 static cputime64_t get_iowait_time(int cpu)
41 {
42 	u64 iowait_time = get_cpu_iowait_time_us(cpu, NULL);
43 	cputime64_t iowait;
44 
45 	if (iowait_time == -1ULL)
46 		/* !NO_HZ so we can rely on cpustat.iowait */
47 		iowait = kstat_cpu(cpu).cpustat.iowait;
48 	else
49 		iowait = usecs_to_cputime(iowait_time);
50 
51 	return iowait;
52 }
53 
54 static int show_stat(struct seq_file *p, void *v)
55 {
56 	int i, j;
57 	unsigned long jif;
58 	cputime64_t user, nice, system, idle, iowait, irq, softirq, steal;
59 	cputime64_t guest, guest_nice;
60 	u64 sum = 0;
61 	u64 sum_softirq = 0;
62 	unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};
63 	struct timespec boottime;
64 
65 	user = nice = system = idle = iowait =
66 		irq = softirq = steal = cputime64_zero;
67 	guest = guest_nice = cputime64_zero;
68 	getboottime(&boottime);
69 	jif = boottime.tv_sec;
70 
71 	for_each_possible_cpu(i) {
72 		user = cputime64_add(user, kstat_cpu(i).cpustat.user);
73 		nice = cputime64_add(nice, kstat_cpu(i).cpustat.nice);
74 		system = cputime64_add(system, kstat_cpu(i).cpustat.system);
75 		idle = cputime64_add(idle, get_idle_time(i));
76 		iowait = cputime64_add(iowait, get_iowait_time(i));
77 		irq = cputime64_add(irq, kstat_cpu(i).cpustat.irq);
78 		softirq = cputime64_add(softirq, kstat_cpu(i).cpustat.softirq);
79 		steal = cputime64_add(steal, kstat_cpu(i).cpustat.steal);
80 		guest = cputime64_add(guest, kstat_cpu(i).cpustat.guest);
81 		guest_nice = cputime64_add(guest_nice,
82 			kstat_cpu(i).cpustat.guest_nice);
83 		sum += kstat_cpu_irqs_sum(i);
84 		sum += arch_irq_stat_cpu(i);
85 
86 		for (j = 0; j < NR_SOFTIRQS; j++) {
87 			unsigned int softirq_stat = kstat_softirqs_cpu(j, i);
88 
89 			per_softirq_sums[j] += softirq_stat;
90 			sum_softirq += softirq_stat;
91 		}
92 	}
93 	sum += arch_irq_stat();
94 
95 	seq_printf(p, "cpu  %llu %llu %llu %llu %llu %llu %llu %llu %llu "
96 		"%llu\n",
97 		(unsigned long long)cputime64_to_clock_t(user),
98 		(unsigned long long)cputime64_to_clock_t(nice),
99 		(unsigned long long)cputime64_to_clock_t(system),
100 		(unsigned long long)cputime64_to_clock_t(idle),
101 		(unsigned long long)cputime64_to_clock_t(iowait),
102 		(unsigned long long)cputime64_to_clock_t(irq),
103 		(unsigned long long)cputime64_to_clock_t(softirq),
104 		(unsigned long long)cputime64_to_clock_t(steal),
105 		(unsigned long long)cputime64_to_clock_t(guest),
106 		(unsigned long long)cputime64_to_clock_t(guest_nice));
107 	for_each_online_cpu(i) {
108 		/* Copy values here to work around gcc-2.95.3, gcc-2.96 */
109 		user = kstat_cpu(i).cpustat.user;
110 		nice = kstat_cpu(i).cpustat.nice;
111 		system = kstat_cpu(i).cpustat.system;
112 		idle = get_idle_time(i);
113 		iowait = get_iowait_time(i);
114 		irq = kstat_cpu(i).cpustat.irq;
115 		softirq = kstat_cpu(i).cpustat.softirq;
116 		steal = kstat_cpu(i).cpustat.steal;
117 		guest = kstat_cpu(i).cpustat.guest;
118 		guest_nice = kstat_cpu(i).cpustat.guest_nice;
119 		seq_printf(p,
120 			"cpu%d %llu %llu %llu %llu %llu %llu %llu %llu %llu "
121 			"%llu\n",
122 			i,
123 			(unsigned long long)cputime64_to_clock_t(user),
124 			(unsigned long long)cputime64_to_clock_t(nice),
125 			(unsigned long long)cputime64_to_clock_t(system),
126 			(unsigned long long)cputime64_to_clock_t(idle),
127 			(unsigned long long)cputime64_to_clock_t(iowait),
128 			(unsigned long long)cputime64_to_clock_t(irq),
129 			(unsigned long long)cputime64_to_clock_t(softirq),
130 			(unsigned long long)cputime64_to_clock_t(steal),
131 			(unsigned long long)cputime64_to_clock_t(guest),
132 			(unsigned long long)cputime64_to_clock_t(guest_nice));
133 	}
134 	seq_printf(p, "intr %llu", (unsigned long long)sum);
135 
136 	/* sum again ? it could be updated? */
137 	for_each_irq_nr(j)
138 		seq_printf(p, " %u", kstat_irqs(j));
139 
140 	seq_printf(p,
141 		"\nctxt %llu\n"
142 		"btime %lu\n"
143 		"processes %lu\n"
144 		"procs_running %lu\n"
145 		"procs_blocked %lu\n",
146 		nr_context_switches(),
147 		(unsigned long)jif,
148 		total_forks,
149 		nr_running(),
150 		nr_iowait());
151 
152 	seq_printf(p, "softirq %llu", (unsigned long long)sum_softirq);
153 
154 	for (i = 0; i < NR_SOFTIRQS; i++)
155 		seq_printf(p, " %u", per_softirq_sums[i]);
156 	seq_putc(p, '\n');
157 
158 	return 0;
159 }
160 
161 static int stat_open(struct inode *inode, struct file *file)
162 {
163 	unsigned size = 4096 * (1 + num_possible_cpus() / 32);
164 	char *buf;
165 	struct seq_file *m;
166 	int res;
167 
168 	/* don't ask for more than the kmalloc() max size */
169 	if (size > KMALLOC_MAX_SIZE)
170 		size = KMALLOC_MAX_SIZE;
171 	buf = kmalloc(size, GFP_KERNEL);
172 	if (!buf)
173 		return -ENOMEM;
174 
175 	res = single_open(file, show_stat, NULL);
176 	if (!res) {
177 		m = file->private_data;
178 		m->buf = buf;
179 		m->size = size;
180 	} else
181 		kfree(buf);
182 	return res;
183 }
184 
185 static const struct file_operations proc_stat_operations = {
186 	.open		= stat_open,
187 	.read		= seq_read,
188 	.llseek		= seq_lseek,
189 	.release	= single_release,
190 };
191 
192 static int __init proc_stat_init(void)
193 {
194 	proc_create("stat", 0, NULL, &proc_stat_operations);
195 	return 0;
196 }
197 module_init(proc_stat_init);
198