fs/proc/stat.c

   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/time_namespace.h>
  14 #include <linux/irqnr.h>
  15 #include <linux/sched/cputime.h>
  16 #include <linux/tick.h>
  17
  18 #ifndef arch_irq_stat_cpu
  19 #define arch_irq_stat_cpu(cpu) 0
  20 #endif
  21 #ifndef arch_irq_stat
  22 #define arch_irq_stat() 0
  23 #endif
  24
  25 #ifdef arch_idle_time
  26
  27 static u64 get_idle_time(struct kernel_cpustat *kcs, int cpu)
  28 {
  29         u64 idle;
  30
  31         idle = kcs->cpustat[CPUTIME_IDLE];
  32         if (cpu_online(cpu) && !nr_iowait_cpu(cpu))
  33                 idle += arch_idle_time(cpu);
  34         return idle;
  35 }
  36
  37 static u64 get_iowait_time(struct kernel_cpustat *kcs, int cpu)
  38 {
  39         u64 iowait;
  40
  41         iowait = kcs->cpustat[CPUTIME_IOWAIT];
  42         if (cpu_online(cpu) && nr_iowait_cpu(cpu))
  43                 iowait += arch_idle_time(cpu);
  44         return iowait;
  45 }
  46
  47 #else
  48
  49 static u64 get_idle_time(struct kernel_cpustat *kcs, int cpu)
  50 {
  51         u64 idle, idle_usecs = -1ULL;
  52
  53         if (cpu_online(cpu))
  54                 idle_usecs = get_cpu_idle_time_us(cpu, NULL);
  55
  56         if (idle_usecs == -1ULL)
  57                 /* !NO_HZ or cpu offline so we can rely on cpustat.idle */
  58                 idle = kcs->cpustat[CPUTIME_IDLE];
  59         else
  60                 idle = idle_usecs * NSEC_PER_USEC;
  61
  62         return idle;
  63 }
  64
  65 static u64 get_iowait_time(struct kernel_cpustat *kcs, int cpu)
  66 {
  67         u64 iowait, iowait_usecs = -1ULL;
  68
  69         if (cpu_online(cpu))
  70                 iowait_usecs = get_cpu_iowait_time_us(cpu, NULL);
  71
  72         if (iowait_usecs == -1ULL)
  73                 /* !NO_HZ or cpu offline so we can rely on cpustat.iowait */
  74                 iowait = kcs->cpustat[CPUTIME_IOWAIT];
  75         else
  76                 iowait = iowait_usecs * NSEC_PER_USEC;
  77
  78         return iowait;
  79 }
  80
  81 #endif
  82
  83 static void show_irq_gap(struct seq_file *p, unsigned int gap)
  84 {
  85         static const char zeros[] = " 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0";
  86
  87         while (gap > 0) {
  88                 unsigned int inc;
  89
  90                 inc = min_t(unsigned int, gap, ARRAY_SIZE(zeros) / 2);
  91                 seq_write(p, zeros, 2 * inc);
  92                 gap -= inc;
  93         }
  94 }
  95
  96 static void show_all_irqs(struct seq_file *p)
  97 {
  98         unsigned int i, next = 0;
  99
 100         for_each_active_irq(i) {
 101                 show_irq_gap(p, i - next);
 102                 seq_put_decimal_ull(p, " ", kstat_irqs_usr(i));
 103                 next = i + 1;
 104         }
 105         show_irq_gap(p, nr_irqs - next);
 106 }
 107
 108 static int show_stat(struct seq_file *p, void *v)
 109 {
 110         int i, j;
 111         u64 user, nice, system, idle, iowait, irq, softirq, steal;
 112         u64 guest, guest_nice;
 113         u64 sum = 0;
 114         u64 sum_softirq = 0;
 115         unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};
 116         struct timespec64 boottime;
 117
 118         user = nice = system = idle = iowait =
 119                 irq = softirq = steal = 0;
 120         guest = guest_nice = 0;
 121         getboottime64(&boottime);
 122         /* shift boot timestamp according to the timens offset */
 123         timens_sub_boottime(&boottime);
 124
 125         for_each_possible_cpu(i) {
 126                 struct kernel_cpustat kcpustat;
 127                 u64 *cpustat = kcpustat.cpustat;
 128
 129                 kcpustat_cpu_fetch(&kcpustat, i);
 130
 131                 user            += cpustat[CPUTIME_USER];
 132                 nice            += cpustat[CPUTIME_NICE];
 133                 system          += cpustat[CPUTIME_SYSTEM];
 134                 idle            += get_idle_time(&kcpustat, i);
 135                 iowait          += get_iowait_time(&kcpustat, i);
 136                 irq             += cpustat[CPUTIME_IRQ];
 137                 softirq         += cpustat[CPUTIME_SOFTIRQ];
 138                 steal           += cpustat[CPUTIME_STEAL];
 139                 guest           += cpustat[CPUTIME_GUEST];
 140                 guest_nice      += cpustat[CPUTIME_GUEST_NICE];
 141                 sum             += kstat_cpu_irqs_sum(i);
 142                 sum             += arch_irq_stat_cpu(i);
 143
 144                 for (j = 0; j < NR_SOFTIRQS; j++) {
 145                         unsigned int softirq_stat = kstat_softirqs_cpu(j, i);
 146
 147                         per_softirq_sums[j] += softirq_stat;
 148                         sum_softirq += softirq_stat;
 149                 }
 150         }
 151         sum += arch_irq_stat();
 152
 153         seq_put_decimal_ull(p, "cpu  ", nsec_to_clock_t(user));
 154         seq_put_decimal_ull(p, " ", nsec_to_clock_t(nice));
 155         seq_put_decimal_ull(p, " ", nsec_to_clock_t(system));
 156         seq_put_decimal_ull(p, " ", nsec_to_clock_t(idle));
 157         seq_put_decimal_ull(p, " ", nsec_to_clock_t(iowait));
 158         seq_put_decimal_ull(p, " ", nsec_to_clock_t(irq));
 159         seq_put_decimal_ull(p, " ", nsec_to_clock_t(softirq));
 160         seq_put_decimal_ull(p, " ", nsec_to_clock_t(steal));
 161         seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest));
 162         seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest_nice));
 163         seq_putc(p, '\n');
 164
 165         for_each_online_cpu(i) {
 166                 struct kernel_cpustat kcpustat;
 167                 u64 *cpustat = kcpustat.cpustat;
 168
 169                 kcpustat_cpu_fetch(&kcpustat, i);
 170
 171                 /* Copy values here to work around gcc-2.95.3, gcc-2.96 */
 172                 user            = cpustat[CPUTIME_USER];
 173                 nice            = cpustat[CPUTIME_NICE];
 174                 system          = cpustat[CPUTIME_SYSTEM];
 175                 idle            = get_idle_time(&kcpustat, i);
 176                 iowait          = get_iowait_time(&kcpustat, i);
 177                 irq             = cpustat[CPUTIME_IRQ];
 178                 softirq         = cpustat[CPUTIME_SOFTIRQ];
 179                 steal           = cpustat[CPUTIME_STEAL];
 180                 guest           = cpustat[CPUTIME_GUEST];
 181                 guest_nice      = cpustat[CPUTIME_GUEST_NICE];
 182                 seq_printf(p, "cpu%d", i);
 183                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(user));
 184                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(nice));
 185                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(system));
 186                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(idle));
 187                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(iowait));
 188                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(irq));
 189                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(softirq));
 190                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(steal));
 191                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest));
 192                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest_nice));
 193                 seq_putc(p, '\n');
 194         }
 195         seq_put_decimal_ull(p, "intr ", (unsigned long long)sum);
 196
 197         show_all_irqs(p);
 198
 199         seq_printf(p,
 200                 "\nctxt %llu\n"
 201                 "btime %llu\n"
 202                 "processes %lu\n"
 203                 "procs_running %lu\n"
 204                 "procs_blocked %lu\n",
 205                 nr_context_switches(),
 206                 (unsigned long long)boottime.tv_sec,
 207                 total_forks,
 208                 nr_running(),
 209                 nr_iowait());
 210
 211         seq_put_decimal_ull(p, "softirq ", (unsigned long long)sum_softirq);
 212
 213         for (i = 0; i < NR_SOFTIRQS; i++)
 214                 seq_put_decimal_ull(p, " ", per_softirq_sums[i]);
 215         seq_putc(p, '\n');
 216
 217         return 0;
 218 }
 219
 220 static int stat_open(struct inode *inode, struct file *file)
 221 {
 222         unsigned int size = 1024 + 128 * num_online_cpus();
 223
 224         /* minimum size to display an interrupt count : 2 bytes */
 225         size += 2 * nr_irqs;
 226         return single_open_size(file, show_stat, NULL, size);
 227 }
 228
 229 static const struct proc_ops stat_proc_ops = {
 230         .proc_flags     = PROC_ENTRY_PERMANENT,
 231         .proc_open      = stat_open,
 232         .proc_read_iter = seq_read_iter,
 233         .proc_lseek     = seq_lseek,
 234         .proc_release   = single_release,
 235 };
 236
 237 static int __init proc_stat_init(void)
 238 {
 239         proc_create("stat", 0, NULL, &stat_proc_ops);
 240         return 0;
 241 }
 242 fs_initcall(proc_stat_init);