1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/fs.h> 3 #include <linux/init.h> 4 #include <linux/proc_fs.h> 5 #include <linux/sched.h> 6 #include <linux/seq_file.h> 7 #include <linux/time.h> 8 #include <linux/time_namespace.h> 9 #include <linux/kernel_stat.h> 10 #include "internal.h" 11 12 static int uptime_proc_show(struct seq_file *m, void *v) 13 { 14 struct timespec64 uptime; 15 struct timespec64 idle; 16 u64 idle_nsec; 17 u32 rem; 18 int i; 19 20 idle_nsec = 0; 21 for_each_possible_cpu(i) { 22 struct kernel_cpustat kcs; 23 24 kcpustat_cpu_fetch(&kcs, i); 25 idle_nsec += get_idle_time(&kcs, i); 26 } 27 28 ktime_get_boottime_ts64(&uptime); 29 timens_add_boottime(&uptime); 30 31 idle.tv_sec = div_u64_rem(idle_nsec, NSEC_PER_SEC, &rem); 32 idle.tv_nsec = rem; 33 seq_printf(m, "%lu.%02lu %lu.%02lu\n", 34 (unsigned long) uptime.tv_sec, 35 (uptime.tv_nsec / (NSEC_PER_SEC / 100)), 36 (unsigned long) idle.tv_sec, 37 (idle.tv_nsec / (NSEC_PER_SEC / 100))); 38 return 0; 39 } 40 41 static int __init proc_uptime_init(void) 42 { 43 struct proc_dir_entry *pde; 44 45 pde = proc_create_single("uptime", 0, NULL, uptime_proc_show); 46 pde_make_permanent(pde); 47 return 0; 48 } 49 fs_initcall(proc_uptime_init); 50