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 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 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 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