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/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
  26 static u64 get_idle_time(int cpu)
  27 {
  28         u64 idle;
  29
  30         idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
  31         if (cpu_online(cpu) && !nr_iowait_cpu(cpu))
  32                 idle += arch_idle_time(cpu);
  33         return idle;
  34 }
  35
  36 static u64 get_iowait_time(int cpu)
  37 {
  38         u64 iowait;
  39
  40         iowait = kcpustat_cpu(cpu).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
  48 static u64 get_idle_time(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 = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
  58         else
  59                 idle = idle_usecs * NSEC_PER_USEC;
  60
  61         return idle;
  62 }
  63
  64 static u64 get_iowait_time(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 = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
  74         else
  75                 iowait = iowait_usecs * NSEC_PER_USEC;
  76
  77         return iowait;
  78 }
  79
  80 #endif
  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
  97         for_each_possible_cpu(i) {
  98                 user += kcpustat_cpu(i).cpustat[CPUTIME_USER];
  99                 nice += kcpustat_cpu(i).cpustat[CPUTIME_NICE];
 100                 system += kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
 101                 idle += get_idle_time(i);
 102                 iowait += get_iowait_time(i);
 103                 irq += kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
 104                 softirq += kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ];
 105                 steal += kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
 106                 guest += kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
 107                 guest_nice += kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
 108                 sum += kstat_cpu_irqs_sum(i);
 109                 sum += arch_irq_stat_cpu(i);
 110
 111                 for (j = 0; j < NR_SOFTIRQS; j++) {
 112                         unsigned int softirq_stat = kstat_softirqs_cpu(j, i);
 113
 114                         per_softirq_sums[j] += softirq_stat;
 115                         sum_softirq += softirq_stat;
 116                 }
 117         }
 118         sum += arch_irq_stat();
 119
 120         seq_put_decimal_ull(p, "cpu  ", nsec_to_clock_t(user));
 121         seq_put_decimal_ull(p, " ", nsec_to_clock_t(nice));
 122         seq_put_decimal_ull(p, " ", nsec_to_clock_t(system));
 123         seq_put_decimal_ull(p, " ", nsec_to_clock_t(idle));
 124         seq_put_decimal_ull(p, " ", nsec_to_clock_t(iowait));
 125         seq_put_decimal_ull(p, " ", nsec_to_clock_t(irq));
 126         seq_put_decimal_ull(p, " ", nsec_to_clock_t(softirq));
 127         seq_put_decimal_ull(p, " ", nsec_to_clock_t(steal));
 128         seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest));
 129         seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest_nice));
 130         seq_putc(p, '\n');
 131
 132         for_each_online_cpu(i) {
 133                 /* Copy values here to work around gcc-2.95.3, gcc-2.96 */
 134                 user = kcpustat_cpu(i).cpustat[CPUTIME_USER];
 135                 nice = kcpustat_cpu(i).cpustat[CPUTIME_NICE];
 136                 system = kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
 137                 idle = get_idle_time(i);
 138                 iowait = get_iowait_time(i);
 139                 irq = kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
 140                 softirq = kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ];
 141                 steal = kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
 142                 guest = kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
 143                 guest_nice = kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
 144                 seq_printf(p, "cpu%d", i);
 145                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(user));
 146                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(nice));
 147                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(system));
 148                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(idle));
 149                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(iowait));
 150                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(irq));
 151                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(softirq));
 152                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(steal));
 153                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest));
 154                 seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest_nice));
 155                 seq_putc(p, '\n');
 156         }
 157         seq_put_decimal_ull(p, "intr ", (unsigned long long)sum);
 158
 159         /* sum again ? it could be updated? */
 160         for_each_irq_nr(j)
 161                 seq_put_decimal_ull(p, " ", kstat_irqs_usr(j));
 162
 163         seq_printf(p,
 164                 "\nctxt %llu\n"
 165                 "btime %llu\n"
 166                 "processes %lu\n"
 167                 "procs_running %lu\n"
 168                 "procs_blocked %lu\n",
 169                 nr_context_switches(),
 170                 (unsigned long long)boottime.tv_sec,
 171                 total_forks,
 172                 nr_running(),
 173                 nr_iowait());
 174
 175         seq_put_decimal_ull(p, "softirq ", (unsigned long long)sum_softirq);
 176
 177         for (i = 0; i < NR_SOFTIRQS; i++)
 178                 seq_put_decimal_ull(p, " ", per_softirq_sums[i]);
 179         seq_putc(p, '\n');
 180
 181         return 0;
 182 }
 183
 184 static int stat_open(struct inode *inode, struct file *file)
 185 {
 186         size_t size = 1024 + 128 * num_online_cpus();
 187
 188         /* minimum size to display an interrupt count : 2 bytes */
 189         size += 2 * nr_irqs;
 190         return single_open_size(file, show_stat, NULL, size);
 191 }
 192
 193 static const struct file_operations proc_stat_operations = {
 194         .open           = stat_open,
 195         .read           = seq_read,
 196         .llseek         = seq_lseek,
 197         .release        = single_release,
 198 };
 199
 200 static int __init proc_stat_init(void)
 201 {
 202         proc_create("stat", 0, NULL, &proc_stat_operations);
 203         return 0;
 204 }
 205 fs_initcall(proc_stat_init);