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(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
  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
  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
  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
  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
  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
 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
 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
 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);