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 #ifdef CONFIG_SMP
  16 static inline void show_easstat(struct seq_file *seq, struct eas_stats *stats)
  17 {
  18         /* eas-specific runqueue stats */
  19         seq_printf(seq, "eas %llu %llu %llu %llu %llu %llu ",
  20             stats->sis_attempts, stats->sis_idle, stats->sis_cache_affine,
  21             stats->sis_suff_cap, stats->sis_idle_cpu, stats->sis_count);
  22
  23         seq_printf(seq, "%llu %llu %llu %llu %llu %llu %llu ",
  24             stats->secb_attempts, stats->secb_sync, stats->secb_idle_bt,
  25             stats->secb_insuff_cap, stats->secb_no_nrg_sav,
  26             stats->secb_nrg_sav, stats->secb_count);
  27
  28         seq_printf(seq, "%llu %llu %llu %llu %llu ",
  29             stats->fbt_attempts, stats->fbt_no_cpu, stats->fbt_no_sd,
  30             stats->fbt_pref_idle, stats->fbt_count);
  31
  32         seq_printf(seq, "%llu %llu\n",
  33             stats->cas_attempts, stats->cas_count);
  34 }
  35 #endif
  36
  37 static int show_schedstat(struct seq_file *seq, void *v)
  38 {
  39         int cpu;
  40
  41         if (v == (void *)1) {
  42                 seq_printf(seq, "version %d\n", SCHEDSTAT_VERSION);
  43                 seq_printf(seq, "timestamp %lu\n", jiffies);
  44         } else {
  45                 struct rq *rq;
  46 #ifdef CONFIG_SMP
  47                 struct sched_domain *sd;
  48                 int dcount = 0;
  49 #endif
  50                 cpu = (unsigned long)(v - 2);
  51                 rq = cpu_rq(cpu);
  52
  53                 /* runqueue-specific stats */
  54                 seq_printf(seq,
  55                     "cpu%d %u 0 %u %u %u %u %llu %llu %lu",
  56                     cpu, rq->yld_count,
  57                     rq->sched_count, rq->sched_goidle,
  58                     rq->ttwu_count, rq->ttwu_local,
  59                     rq->rq_cpu_time,
  60                     rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
  61
  62                 seq_printf(seq, "\n");
  63
  64 #ifdef CONFIG_SMP
  65                 show_easstat(seq, &rq->eas_stats);
  66
  67                 /* domain-specific stats */
  68                 rcu_read_lock();
  69                 for_each_domain(cpu, sd) {
  70                         enum cpu_idle_type itype;
  71
  72                         seq_printf(seq, "domain%d %*pb", dcount++,
  73                                    cpumask_pr_args(sched_domain_span(sd)));
  74                         for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES;
  75                                         itype++) {
  76                                 seq_printf(seq, " %u %u %u %u %u %u %u %u",
  77                                     sd->lb_count[itype],
  78                                     sd->lb_balanced[itype],
  79                                     sd->lb_failed[itype],
  80                                     sd->lb_imbalance[itype],
  81                                     sd->lb_gained[itype],
  82                                     sd->lb_hot_gained[itype],
  83                                     sd->lb_nobusyq[itype],
  84                                     sd->lb_nobusyg[itype]);
  85                         }
  86                         seq_printf(seq,
  87                                    " %u %u %u %u %u %u %u %u %u %u %u %u\n",
  88                             sd->alb_count, sd->alb_failed, sd->alb_pushed,
  89                             sd->sbe_count, sd->sbe_balanced, sd->sbe_pushed,
  90                             sd->sbf_count, sd->sbf_balanced, sd->sbf_pushed,
  91                             sd->ttwu_wake_remote, sd->ttwu_move_affine,
  92                             sd->ttwu_move_balance);
  93
  94                         show_easstat(seq, &sd->eas_stats);
  95                 }
  96                 rcu_read_unlock();
  97 #endif
  98         }
  99         return 0;
 100 }
 101
 102 /*
 103  * This itererator needs some explanation.
 104  * It returns 1 for the header position.
 105  * This means 2 is cpu 0.
 106  * In a hotplugged system some cpus, including cpu 0, may be missing so we have
 107  * to use cpumask_* to iterate over the cpus.
 108  */
 109 static void *schedstat_start(struct seq_file *file, loff_t *offset)
 110 {
 111         unsigned long n = *offset;
 112
 113         if (n == 0)
 114                 return (void *) 1;
 115
 116         n--;
 117
 118         if (n > 0)
 119                 n = cpumask_next(n - 1, cpu_online_mask);
 120         else
 121                 n = cpumask_first(cpu_online_mask);
 122
 123         *offset = n + 1;
 124
 125         if (n < nr_cpu_ids)
 126                 return (void *)(unsigned long)(n + 2);
 127         return NULL;
 128 }
 129
 130 static void *schedstat_next(struct seq_file *file, void *data, loff_t *offset)
 131 {
 132         (*offset)++;
 133         return schedstat_start(file, offset);
 134 }
 135
 136 static void schedstat_stop(struct seq_file *file, void *data)
 137 {
 138 }
 139
 140 static const struct seq_operations schedstat_sops = {
 141         .start = schedstat_start,
 142         .next  = schedstat_next,
 143         .stop  = schedstat_stop,
 144         .show  = show_schedstat,
 145 };
 146
 147 static int schedstat_open(struct inode *inode, struct file *file)
 148 {
 149         return seq_open(file, &schedstat_sops);
 150 }
 151
 152 static const struct file_operations proc_schedstat_operations = {
 153         .open    = schedstat_open,
 154         .read    = seq_read,
 155         .llseek  = seq_lseek,
 156         .release = seq_release,
 157 };
 158
 159 static int __init proc_schedstat_init(void)
 160 {
 161         proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
 162         return 0;
 163 }
 164 subsys_initcall(proc_schedstat_init);