fs/proc/stat.c

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