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