xref: /linux/fs/proc/uptime.c (revision bcefe12eff5dca6fdfa94ed85e5bee66380d5cd9)
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);
49