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 <asm/cputime.h>
   8
   9 static int uptime_proc_show(struct seq_file *m, void *v)
  10 {
  11         struct timespec uptime;
  12         struct timespec idle;
  13         cputime_t idletime = cputime_add(init_task.utime, init_task.stime);
  14
  15         do_posix_clock_monotonic_gettime(&uptime);
  16         monotonic_to_bootbased(&uptime);
  17         cputime_to_timespec(idletime, &idle);
  18         seq_printf(m, "%lu.%02lu %lu.%02lu\n",
  19                         (unsigned long) uptime.tv_sec,
  20                         (uptime.tv_nsec / (NSEC_PER_SEC / 100)),
  21                         (unsigned long) idle.tv_sec,
  22                         (idle.tv_nsec / (NSEC_PER_SEC / 100)));
  23         return 0;
  24 }
  25
  26 static int uptime_proc_open(struct inode *inode, struct file *file)
  27 {
  28         return single_open(file, uptime_proc_show, NULL);
  29 }
  30
  31 static const struct file_operations uptime_proc_fops = {
  32         .open           = uptime_proc_open,
  33         .read           = seq_read,
  34         .llseek         = seq_lseek,
  35         .release        = single_release,
  36 };
  37
  38 static int __init proc_uptime_init(void)
  39 {
  40         proc_create("uptime", 0, NULL, &uptime_proc_fops);
  41         return 0;
  42 }
  43 module_init(proc_uptime_init);