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