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/seq_file.h>
   9 #include <linux/slab.h>
  10 #include <linux/time.h>
  11 #include <linux/irqnr.h>
  12 #include <asm/cputime.h>
  13 #include <linux/tick.h>
  14
  15 #ifndef arch_irq_stat_cpu
  16 #define arch_irq_stat_cpu(cpu) 0
  17 #endif
  18 #ifndef arch_irq_stat
  19 #define arch_irq_stat() 0
  20 #endif
  21 #ifndef arch_idle_time
  22 #define arch_idle_time(cpu) 0
  23 #endif
  24
  25 static u64 get_idle_time(int cpu)
  26 {
  27         u64 idle, idle_time = get_cpu_idle_time_us(cpu, NULL);
  28
  29         if (idle_time == -1ULL) {
  30                 /* !NO_HZ so we can rely on cpustat.idle */
  31                 idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
  32                 idle += arch_idle_time(cpu);
  33         } else
  34                 idle = usecs_to_cputime64(idle_time);
  35
  36         return idle;
  37 }
  38
  39 static u64 get_iowait_time(int cpu)
  40 {
  41         u64 iowait, iowait_time = get_cpu_iowait_time_us(cpu, NULL);
  42
  43         if (iowait_time == -1ULL)
  44                 /* !NO_HZ so we can rely on cpustat.iowait */
  45                 iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
  46         else
  47                 iowait = usecs_to_cputime64(iowait_time);
  48
  49         return iowait;
  50 }
  51
  52 static int show_stat(struct seq_file *p, void *v)
  53 {
  54         int i, j;
  55         unsigned long jif;
  56         u64 user, nice, system, idle, iowait, irq, softirq, steal;
  57         u64 guest, guest_nice;
  58         u64 sum = 0;
  59         u64 sum_softirq = 0;
  60         unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};
  61         struct timespec boottime;
  62
  63         user = nice = system = idle = iowait =
  64                 irq = softirq = steal = 0;
  65         guest = guest_nice = 0;
  66         getboottime(&boottime);
  67         jif = boottime.tv_sec;
  68
  69         for_each_possible_cpu(i) {
  70                 user += kcpustat_cpu(i).cpustat[CPUTIME_USER];
  71                 nice += kcpustat_cpu(i).cpustat[CPUTIME_NICE];
  72                 system += kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
  73                 idle += get_idle_time(i);
  74                 iowait += get_iowait_time(i);
  75                 irq += kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
  76                 softirq += kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ];
  77                 steal += kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
  78                 guest += kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
  79                 guest_nice += kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
  80                 sum += kstat_cpu_irqs_sum(i);
  81                 sum += arch_irq_stat_cpu(i);
  82
  83                 for (j = 0; j < NR_SOFTIRQS; j++) {
  84                         unsigned int softirq_stat = kstat_softirqs_cpu(j, i);
  85
  86                         per_softirq_sums[j] += softirq_stat;
  87                         sum_softirq += softirq_stat;
  88                 }
  89         }
  90         sum += arch_irq_stat();
  91
  92         seq_puts(p, "cpu ");
  93         seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(user));
  94         seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(nice));
  95         seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(system));
  96         seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(idle));
  97         seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(iowait));
  98         seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(irq));
  99         seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(softirq));
 100         seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(steal));
 101         seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest));
 102         seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest_nice));
 103         seq_putc(p, '\n');
 104
 105         for_each_online_cpu(i) {
 106                 /* Copy values here to work around gcc-2.95.3, gcc-2.96 */
 107                 user = kcpustat_cpu(i).cpustat[CPUTIME_USER];
 108                 nice = kcpustat_cpu(i).cpustat[CPUTIME_NICE];
 109                 system = kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
 110                 idle = get_idle_time(i);
 111                 iowait = get_iowait_time(i);
 112                 irq = kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
 113                 softirq = kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ];
 114                 steal = kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
 115                 guest = kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
 116                 guest_nice = kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
 117                 seq_printf(p, "cpu%d", i);
 118                 seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(user));
 119                 seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(nice));
 120                 seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(system));
 121                 seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(idle));
 122                 seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(iowait));
 123                 seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(irq));
 124                 seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(softirq));
 125                 seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(steal));
 126                 seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest));
 127                 seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest_nice));
 128                 seq_putc(p, '\n');
 129         }
 130         seq_printf(p, "intr %llu", (unsigned long long)sum);
 131
 132         /* sum again ? it could be updated? */
 133         for_each_irq_nr(j)
 134                 seq_put_decimal_ull(p, ' ', kstat_irqs(j));
 135
 136         seq_printf(p,
 137                 "\nctxt %llu\n"
 138                 "btime %lu\n"
 139                 "processes %lu\n"
 140                 "procs_running %lu\n"
 141                 "procs_blocked %lu\n",
 142                 nr_context_switches(),
 143                 (unsigned long)jif,
 144                 total_forks,
 145                 nr_running(),
 146                 nr_iowait());
 147
 148         seq_printf(p, "softirq %llu", (unsigned long long)sum_softirq);
 149
 150         for (i = 0; i < NR_SOFTIRQS; i++)
 151                 seq_put_decimal_ull(p, ' ', per_softirq_sums[i]);
 152         seq_putc(p, '\n');
 153
 154         return 0;
 155 }
 156
 157 static int stat_open(struct inode *inode, struct file *file)
 158 {
 159         unsigned size = 1024 + 128 * num_possible_cpus();
 160         char *buf;
 161         struct seq_file *m;
 162         int res;
 163
 164         /* minimum size to display an interrupt count : 2 bytes */
 165         size += 2 * nr_irqs;
 166
 167         /* don't ask for more than the kmalloc() max size */
 168         if (size > KMALLOC_MAX_SIZE)
 169                 size = KMALLOC_MAX_SIZE;
 170         buf = kmalloc(size, GFP_KERNEL);
 171         if (!buf)
 172                 return -ENOMEM;
 173
 174         res = single_open(file, show_stat, NULL);
 175         if (!res) {
 176                 m = file->private_data;
 177                 m->buf = buf;
 178                 m->size = ksize(buf);
 179         } else
 180                 kfree(buf);
 181         return res;
 182 }
 183
 184 static const struct file_operations proc_stat_operations = {
 185         .open           = stat_open,
 186         .read           = seq_read,
 187         .llseek         = seq_lseek,
 188         .release        = single_release,
 189 };
 190
 191 static int __init proc_stat_init(void)
 192 {
 193         proc_create("stat", 0, NULL, &proc_stat_operations);
 194         return 0;
 195 }
 196 module_init(proc_stat_init);