fs/proc/loadavg.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/fs.h>
   3 #include <linux/init.h>
   4 #include <linux/pid_namespace.h>
   5 #include <linux/proc_fs.h>
   6 #include <linux/sched.h>
   7 #include <linux/sched/loadavg.h>
   8 #include <linux/sched/stat.h>
   9 #include <linux/seq_file.h>
  10 #include <linux/seqlock.h>
  11 #include <linux/time.h>
  12
  13 #define LOAD_INT(x) ((x) >> FSHIFT)
  14 #define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
  15
  16 static int loadavg_proc_show(struct seq_file *m, void *v)
  17 {
  18         unsigned long avnrun[3];
  19
  20         get_avenrun(avnrun, FIXED_1/200, 0);
  21
  22         seq_printf(m, "%lu.%02lu %lu.%02lu %lu.%02lu %ld/%d %d\n",
  23                 LOAD_INT(avnrun[0]), LOAD_FRAC(avnrun[0]),
  24                 LOAD_INT(avnrun[1]), LOAD_FRAC(avnrun[1]),
  25                 LOAD_INT(avnrun[2]), LOAD_FRAC(avnrun[2]),
  26                 nr_running(), nr_threads,
  27                 task_active_pid_ns(current)->last_pid);
  28         return 0;
  29 }
  30
  31 static int loadavg_proc_open(struct inode *inode, struct file *file)
  32 {
  33         return single_open(file, loadavg_proc_show, NULL);
  34 }
  35
  36 static const struct file_operations loadavg_proc_fops = {
  37         .open           = loadavg_proc_open,
  38         .read           = seq_read,
  39         .llseek         = seq_lseek,
  40         .release        = single_release,
  41 };
  42
  43 static int __init proc_loadavg_init(void)
  44 {
  45         proc_create("loadavg", 0, NULL, &loadavg_proc_fops);
  46         return 0;
  47 }
  48 fs_initcall(proc_loadavg_init);