fs/proc/uptime.c

   1 #include <linux/fs.h>
   2 #include <linux/init.h>
   3 #include <linux/proc_fs.h>
   4 #include <linux/sched.h>
   5 #include <linux/seq_file.h>
   6 #include <linux/time.h>
   7 #include <linux/kernel_stat.h>
   8 #include <asm/cputime.h>
   9
  10 static int uptime_proc_show(struct seq_file *m, void *v)
  11 {
  12         struct timespec uptime;
  13         struct timespec idle;
  14         int i;
  15         cputime_t idletime = cputime_zero;
  16
  17         for_each_possible_cpu(i)
  18                 idletime = cputime64_add(idletime, kstat_cpu(i).cpustat.idle);
  19
  20         do_posix_clock_monotonic_gettime(&uptime);
  21         monotonic_to_bootbased(&uptime);
  22         cputime_to_timespec(idletime, &idle);
  23         seq_printf(m, "%lu.%02lu %lu.%02lu\n",
  24                         (unsigned long) uptime.tv_sec,
  25                         (uptime.tv_nsec / (NSEC_PER_SEC / 100)),
  26                         (unsigned long) idle.tv_sec,
  27                         (idle.tv_nsec / (NSEC_PER_SEC / 100)));
  28         return 0;
  29 }
  30
  31 static int uptime_proc_open(struct inode *inode, struct file *file)
  32 {
  33         return single_open(file, uptime_proc_show, NULL);
  34 }
  35
  36 static const struct file_operations uptime_proc_fops = {
  37         .open           = uptime_proc_open,
  38         .read           = seq_read,
  39         .llseek         = seq_lseek,
  40         .release        = single_release,
  41 };
  42
  43 static int __init proc_uptime_init(void)
  44 {
  45         proc_create("uptime", 0, NULL, &uptime_proc_fops);
  46         return 0;
  47 }
  48 module_init(proc_uptime_init);