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 <linux/cputime.h>
9
uptime_proc_show(struct seq_file * m,void * v)10 static int uptime_proc_show(struct seq_file *m, void *v)
11 {
12 struct timespec uptime;
13 struct timespec idle;
14 u64 idletime;
15 u64 nsec;
16 u32 rem;
17 int i;
18
19 idletime = 0;
20 for_each_possible_cpu(i)
21 idletime += (__force u64) kcpustat_cpu(i).cpustat[CPUTIME_IDLE];
22
23 get_monotonic_boottime(&uptime);
24 nsec = cputime64_to_jiffies64(idletime) * TICK_NSEC;
25 idle.tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem);
26 idle.tv_nsec = rem;
27 seq_printf(m, "%lu.%02lu %lu.%02lu\n",
28 (unsigned long) uptime.tv_sec,
29 (uptime.tv_nsec / (NSEC_PER_SEC / 100)),
30 (unsigned long) idle.tv_sec,
31 (idle.tv_nsec / (NSEC_PER_SEC / 100)));
32 return 0;
33 }
34
uptime_proc_open(struct inode * inode,struct file * file)35 static int uptime_proc_open(struct inode *inode, struct file *file)
36 {
37 return single_open(file, uptime_proc_show, NULL);
38 }
39
40 static const struct file_operations uptime_proc_fops = {
41 .open = uptime_proc_open,
42 .read = seq_read,
43 .llseek = seq_lseek,
44 .release = single_release,
45 };
46
proc_uptime_init(void)47 static int __init proc_uptime_init(void)
48 {
49 proc_create("uptime", 0, NULL, &uptime_proc_fops);
50 return 0;
51 }
52 fs_initcall(proc_uptime_init);
53