kernel/sched_stats.c

   1
   2 #include <linux/slab.h>
   3 #include <linux/fs.h>
   4 #include <linux/seq_file.h>
   5 #include <linux/proc_fs.h>
   6
   7 #include "sched.h"
   8
   9 /*
  10  * bump this up when changing the output format or the meaning of an existing
  11  * format, so that tools can adapt (or abort)
  12  */
  13 #define SCHEDSTAT_VERSION 15
  14
  15 static int show_schedstat(struct seq_file *seq, void *v)
  16 {
  17         int cpu;
  18         int mask_len = DIV_ROUND_UP(NR_CPUS, 32) * 9;
  19         char *mask_str = kmalloc(mask_len, GFP_KERNEL);
  20
  21         if (mask_str == NULL)
  22                 return -ENOMEM;
  23
  24         seq_printf(seq, "version %d\n", SCHEDSTAT_VERSION);
  25         seq_printf(seq, "timestamp %lu\n", jiffies);
  26         for_each_online_cpu(cpu) {
  27                 struct rq *rq = cpu_rq(cpu);
  28 #ifdef CONFIG_SMP
  29                 struct sched_domain *sd;
  30                 int dcount = 0;
  31 #endif
  32
  33                 /* runqueue-specific stats */
  34                 seq_printf(seq,
  35                     "cpu%d %u %u %u %u %u %u %llu %llu %lu",
  36                     cpu, rq->yld_count,
  37                     rq->sched_switch, rq->sched_count, rq->sched_goidle,
  38                     rq->ttwu_count, rq->ttwu_local,
  39                     rq->rq_cpu_time,
  40                     rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
  41
  42                 seq_printf(seq, "\n");
  43
  44 #ifdef CONFIG_SMP
  45                 /* domain-specific stats */
  46                 rcu_read_lock();
  47                 for_each_domain(cpu, sd) {
  48                         enum cpu_idle_type itype;
  49
  50                         cpumask_scnprintf(mask_str, mask_len,
  51                                           sched_domain_span(sd));
  52                         seq_printf(seq, "domain%d %s", dcount++, mask_str);
  53                         for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES;
  54                                         itype++) {
  55                                 seq_printf(seq, " %u %u %u %u %u %u %u %u",
  56                                     sd->lb_count[itype],
  57                                     sd->lb_balanced[itype],
  58                                     sd->lb_failed[itype],
  59                                     sd->lb_imbalance[itype],
  60                                     sd->lb_gained[itype],
  61                                     sd->lb_hot_gained[itype],
  62                                     sd->lb_nobusyq[itype],
  63                                     sd->lb_nobusyg[itype]);
  64                         }
  65                         seq_printf(seq,
  66                                    " %u %u %u %u %u %u %u %u %u %u %u %u\n",
  67                             sd->alb_count, sd->alb_failed, sd->alb_pushed,
  68                             sd->sbe_count, sd->sbe_balanced, sd->sbe_pushed,
  69                             sd->sbf_count, sd->sbf_balanced, sd->sbf_pushed,
  70                             sd->ttwu_wake_remote, sd->ttwu_move_affine,
  71                             sd->ttwu_move_balance);
  72                 }
  73                 rcu_read_unlock();
  74 #endif
  75         }
  76         kfree(mask_str);
  77         return 0;
  78 }
  79
  80 static int schedstat_open(struct inode *inode, struct file *file)
  81 {
  82         unsigned int size = PAGE_SIZE * (1 + num_online_cpus() / 32);
  83         char *buf = kmalloc(size, GFP_KERNEL);
  84         struct seq_file *m;
  85         int res;
  86
  87         if (!buf)
  88                 return -ENOMEM;
  89         res = single_open(file, show_schedstat, NULL);
  90         if (!res) {
  91                 m = file->private_data;
  92                 m->buf = buf;
  93                 m->size = size;
  94         } else
  95                 kfree(buf);
  96         return res;
  97 }
  98
  99 static const struct file_operations proc_schedstat_operations = {
 100         .open    = schedstat_open,
 101         .read    = seq_read,
 102         .llseek  = seq_lseek,
 103         .release = single_release,
 104 };
 105
 106 static int __init proc_schedstat_init(void)
 107 {
 108         proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
 109         return 0;
 110 }
 111 module_init(proc_schedstat_init);