1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/cpumask.h>
3 #include <linux/fs.h>
4 #include <linux/init.h>
5 #include <linux/interrupt.h>
6 #include <linux/kernel_stat.h>
7 #include <linux/proc_fs.h>
8 #include <linux/sched.h>
9 #include <linux/sched/stat.h>
10 #include <linux/seq_file.h>
11 #include <linux/slab.h>
12 #include <linux/time.h>
13 #include <linux/irqnr.h>
14 #include <linux/sched/cputime.h>
15 #include <linux/tick.h>
16
17 #ifndef arch_irq_stat_cpu
18 #define arch_irq_stat_cpu(cpu) 0
19 #endif
20 #ifndef arch_irq_stat
21 #define arch_irq_stat() 0
22 #endif
23
24 #ifdef arch_idle_time
25
get_idle_time(struct kernel_cpustat * kcs,int cpu)26 static u64 get_idle_time(struct kernel_cpustat *kcs, int cpu)
27 {
28 u64 idle;
29
30 idle = kcs->cpustat[CPUTIME_IDLE];
31 if (cpu_online(cpu) && !nr_iowait_cpu(cpu))
32 idle += arch_idle_time(cpu);
33 return idle;
34 }
35
get_iowait_time(struct kernel_cpustat * kcs,int cpu)36 static u64 get_iowait_time(struct kernel_cpustat *kcs, int cpu)
37 {
38 u64 iowait;
39
40 iowait = kcs->cpustat[CPUTIME_IOWAIT];
41 if (cpu_online(cpu) && nr_iowait_cpu(cpu))
42 iowait += arch_idle_time(cpu);
43 return iowait;
44 }
45
46 #else
47
get_idle_time(struct kernel_cpustat * kcs,int cpu)48 static u64 get_idle_time(struct kernel_cpustat *kcs, int cpu)
49 {
50 u64 idle, idle_usecs = -1ULL;
51
52 if (cpu_online(cpu))
53 idle_usecs = get_cpu_idle_time_us(cpu, NULL);
54
55 if (idle_usecs == -1ULL)
56 /* !NO_HZ or cpu offline so we can rely on cpustat.idle */
57 idle = kcs->cpustat[CPUTIME_IDLE];
58 else
59 idle = idle_usecs * NSEC_PER_USEC;
60
61 return idle;
62 }
63
get_iowait_time(struct kernel_cpustat * kcs,int cpu)64 static u64 get_iowait_time(struct kernel_cpustat *kcs, int cpu)
65 {
66 u64 iowait, iowait_usecs = -1ULL;
67
68 if (cpu_online(cpu))
69 iowait_usecs = get_cpu_iowait_time_us(cpu, NULL);
70
71 if (iowait_usecs == -1ULL)
72 /* !NO_HZ or cpu offline so we can rely on cpustat.iowait */
73 iowait = kcs->cpustat[CPUTIME_IOWAIT];
74 else
75 iowait = iowait_usecs * NSEC_PER_USEC;
76
77 return iowait;
78 }
79
80 #endif
81
show_irq_gap(struct seq_file * p,unsigned int gap)82 static void show_irq_gap(struct seq_file *p, unsigned int gap)
83 {
84 static const char zeros[] = " 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0";
85
86 while (gap > 0) {
87 unsigned int inc;
88
89 inc = min_t(unsigned int, gap, ARRAY_SIZE(zeros) / 2);
90 seq_write(p, zeros, 2 * inc);
91 gap -= inc;
92 }
93 }
94
show_all_irqs(struct seq_file * p)95 static void show_all_irqs(struct seq_file *p)
96 {
97 unsigned int i, next = 0;
98
99 for_each_active_irq(i) {
100 show_irq_gap(p, i - next);
101 seq_put_decimal_ull(p, " ", kstat_irqs_usr(i));
102 next = i + 1;
103 }
104 show_irq_gap(p, nr_irqs - next);
105 }
106
show_stat(struct seq_file * p,void * v)107 static int show_stat(struct seq_file *p, void *v)
108 {
109 int i, j;
110 u64 user, nice, system, idle, iowait, irq, softirq, steal;
111 u64 guest, guest_nice;
112 u64 sum = 0;
113 u64 sum_softirq = 0;
114 unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};
115 struct timespec64 boottime;
116
117 user = nice = system = idle = iowait =
118 irq = softirq = steal = 0;
119 guest = guest_nice = 0;
120 getboottime64(&boottime);
121
122 for_each_possible_cpu(i) {
123 struct kernel_cpustat *kcs = &kcpustat_cpu(i);
124
125 user += kcs->cpustat[CPUTIME_USER];
126 nice += kcs->cpustat[CPUTIME_NICE];
127 system += kcs->cpustat[CPUTIME_SYSTEM];
128 idle += get_idle_time(kcs, i);
129 iowait += get_iowait_time(kcs, i);
130 irq += kcs->cpustat[CPUTIME_IRQ];
131 softirq += kcs->cpustat[CPUTIME_SOFTIRQ];
132 steal += kcs->cpustat[CPUTIME_STEAL];
133 guest += kcs->cpustat[CPUTIME_GUEST];
134 guest_nice += kcs->cpustat[CPUTIME_GUEST_NICE];
135 sum += kstat_cpu_irqs_sum(i);
136 sum += arch_irq_stat_cpu(i);
137
138 for (j = 0; j < NR_SOFTIRQS; j++) {
139 unsigned int softirq_stat = kstat_softirqs_cpu(j, i);
140
141 per_softirq_sums[j] += softirq_stat;
142 sum_softirq += softirq_stat;
143 }
144 }
145 sum += arch_irq_stat();
146
147 seq_put_decimal_ull(p, "cpu ", nsec_to_clock_t(user));
148 seq_put_decimal_ull(p, " ", nsec_to_clock_t(nice));
149 seq_put_decimal_ull(p, " ", nsec_to_clock_t(system));
150 seq_put_decimal_ull(p, " ", nsec_to_clock_t(idle));
151 seq_put_decimal_ull(p, " ", nsec_to_clock_t(iowait));
152 seq_put_decimal_ull(p, " ", nsec_to_clock_t(irq));
153 seq_put_decimal_ull(p, " ", nsec_to_clock_t(softirq));
154 seq_put_decimal_ull(p, " ", nsec_to_clock_t(steal));
155 seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest));
156 seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest_nice));
157 seq_putc(p, '\n');
158
159 for_each_online_cpu(i) {
160 struct kernel_cpustat *kcs = &kcpustat_cpu(i);
161
162 /* Copy values here to work around gcc-2.95.3, gcc-2.96 */
163 user = kcs->cpustat[CPUTIME_USER];
164 nice = kcs->cpustat[CPUTIME_NICE];
165 system = kcs->cpustat[CPUTIME_SYSTEM];
166 idle = get_idle_time(kcs, i);
167 iowait = get_iowait_time(kcs, i);
168 irq = kcs->cpustat[CPUTIME_IRQ];
169 softirq = kcs->cpustat[CPUTIME_SOFTIRQ];
170 steal = kcs->cpustat[CPUTIME_STEAL];
171 guest = kcs->cpustat[CPUTIME_GUEST];
172 guest_nice = kcs->cpustat[CPUTIME_GUEST_NICE];
173 seq_printf(p, "cpu%d", i);
174 seq_put_decimal_ull(p, " ", nsec_to_clock_t(user));
175 seq_put_decimal_ull(p, " ", nsec_to_clock_t(nice));
176 seq_put_decimal_ull(p, " ", nsec_to_clock_t(system));
177 seq_put_decimal_ull(p, " ", nsec_to_clock_t(idle));
178 seq_put_decimal_ull(p, " ", nsec_to_clock_t(iowait));
179 seq_put_decimal_ull(p, " ", nsec_to_clock_t(irq));
180 seq_put_decimal_ull(p, " ", nsec_to_clock_t(softirq));
181 seq_put_decimal_ull(p, " ", nsec_to_clock_t(steal));
182 seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest));
183 seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest_nice));
184 seq_putc(p, '\n');
185 }
186 seq_put_decimal_ull(p, "intr ", (unsigned long long)sum);
187
188 show_all_irqs(p);
189
190 seq_printf(p,
191 "\nctxt %llu\n"
192 "btime %llu\n"
193 "processes %lu\n"
194 "procs_running %lu\n"
195 "procs_blocked %lu\n",
196 nr_context_switches(),
197 (unsigned long long)boottime.tv_sec,
198 total_forks,
199 nr_running(),
200 nr_iowait());
201
202 seq_put_decimal_ull(p, "softirq ", (unsigned long long)sum_softirq);
203
204 for (i = 0; i < NR_SOFTIRQS; i++)
205 seq_put_decimal_ull(p, " ", per_softirq_sums[i]);
206 seq_putc(p, '\n');
207
208 return 0;
209 }
210
stat_open(struct inode * inode,struct file * file)211 static int stat_open(struct inode *inode, struct file *file)
212 {
213 unsigned int size = 1024 + 128 * num_online_cpus();
214
215 /* minimum size to display an interrupt count : 2 bytes */
216 size += 2 * nr_irqs;
217 return single_open_size(file, show_stat, NULL, size);
218 }
219
220 static const struct file_operations proc_stat_operations = {
221 .open = stat_open,
222 .read = seq_read,
223 .llseek = seq_lseek,
224 .release = single_release,
225 };
226
proc_stat_init(void)227 static int __init proc_stat_init(void)
228 {
229 proc_create("stat", 0, NULL, &proc_stat_operations);
230 return 0;
231 }
232 fs_initcall(proc_stat_init);
233