linux/kernel/sched_debug.c
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   1/*
   2 * kernel/time/sched_debug.c
   3 *
   4 * Print the CFS rbtree
   5 *
   6 * Copyright(C) 2007, Red Hat, Inc., Ingo Molnar
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2 as
  10 * published by the Free Software Foundation.
  11 */
  12
  13#include <linux/proc_fs.h>
  14#include <linux/sched.h>
  15#include <linux/seq_file.h>
  16#include <linux/kallsyms.h>
  17#include <linux/utsname.h>
  18
  19static DEFINE_SPINLOCK(sched_debug_lock);
  20
  21/*
  22 * This allows printing both to /proc/sched_debug and
  23 * to the console
  24 */
  25#define SEQ_printf(m, x...)                     \
  26 do {                                           \
  27        if (m)                                  \
  28                seq_printf(m, x);               \
  29        else                                    \
  30                printk(x);                      \
  31 } while (0)
  32
  33/*
  34 * Ease the printing of nsec fields:
  35 */
  36static long long nsec_high(unsigned long long nsec)
  37{
  38        if ((long long)nsec < 0) {
  39                nsec = -nsec;
  40                do_div(nsec, 1000000);
  41                return -nsec;
  42        }
  43        do_div(nsec, 1000000);
  44
  45        return nsec;
  46}
  47
  48static unsigned long nsec_low(unsigned long long nsec)
  49{
  50        if ((long long)nsec < 0)
  51                nsec = -nsec;
  52
  53        return do_div(nsec, 1000000);
  54}
  55
  56#define SPLIT_NS(x) nsec_high(x), nsec_low(x)
  57
  58#ifdef CONFIG_FAIR_GROUP_SCHED
  59static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group *tg)
  60{
  61        struct sched_entity *se = tg->se[cpu];
  62        if (!se)
  63                return;
  64
  65#define P(F) \
  66        SEQ_printf(m, "  .%-30s: %lld\n", #F, (long long)F)
  67#define PN(F) \
  68        SEQ_printf(m, "  .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F))
  69
  70        PN(se->exec_start);
  71        PN(se->vruntime);
  72        PN(se->sum_exec_runtime);
  73#ifdef CONFIG_SCHEDSTATS
  74        PN(se->statistics.wait_start);
  75        PN(se->statistics.sleep_start);
  76        PN(se->statistics.block_start);
  77        PN(se->statistics.sleep_max);
  78        PN(se->statistics.block_max);
  79        PN(se->statistics.exec_max);
  80        PN(se->statistics.slice_max);
  81        PN(se->statistics.wait_max);
  82        PN(se->statistics.wait_sum);
  83        P(se->statistics.wait_count);
  84#endif
  85        P(se->load.weight);
  86#undef PN
  87#undef P
  88}
  89#endif
  90
  91#ifdef CONFIG_CGROUP_SCHED
  92static char group_path[PATH_MAX];
  93
  94static char *task_group_path(struct task_group *tg)
  95{
  96        if (autogroup_path(tg, group_path, PATH_MAX))
  97                return group_path;
  98
  99        /*
 100         * May be NULL if the underlying cgroup isn't fully-created yet
 101         */
 102        if (!tg->css.cgroup) {
 103                group_path[0] = '\0';
 104                return group_path;
 105        }
 106        cgroup_path(tg->css.cgroup, group_path, PATH_MAX);
 107        return group_path;
 108}
 109#endif
 110
 111static void
 112print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
 113{
 114        if (rq->curr == p)
 115                SEQ_printf(m, "R");
 116        else
 117                SEQ_printf(m, " ");
 118
 119        SEQ_printf(m, "%15s %5d %9Ld.%06ld %9Ld %5d ",
 120                p->comm, p->pid,
 121                SPLIT_NS(p->se.vruntime),
 122                (long long)(p->nvcsw + p->nivcsw),
 123                p->prio);
 124#ifdef CONFIG_SCHEDSTATS
 125        SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
 126                SPLIT_NS(p->se.vruntime),
 127                SPLIT_NS(p->se.sum_exec_runtime),
 128                SPLIT_NS(p->se.statistics.sum_sleep_runtime));
 129#else
 130        SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld",
 131                0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L);
 132#endif
 133#ifdef CONFIG_CGROUP_SCHED
 134        SEQ_printf(m, " %s", task_group_path(task_group(p)));
 135#endif
 136
 137        SEQ_printf(m, "\n");
 138}
 139
 140static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
 141{
 142        struct task_struct *g, *p;
 143        unsigned long flags;
 144
 145        SEQ_printf(m,
 146        "\nrunnable tasks:\n"
 147        "            task   PID         tree-key  switches  prio"
 148        "     exec-runtime         sum-exec        sum-sleep\n"
 149        "------------------------------------------------------"
 150        "----------------------------------------------------\n");
 151
 152        read_lock_irqsave(&tasklist_lock, flags);
 153
 154        do_each_thread(g, p) {
 155                if (!p->on_rq || task_cpu(p) != rq_cpu)
 156                        continue;
 157
 158                print_task(m, rq, p);
 159        } while_each_thread(g, p);
 160
 161        read_unlock_irqrestore(&tasklist_lock, flags);
 162}
 163
 164void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 165{
 166        s64 MIN_vruntime = -1, min_vruntime, max_vruntime = -1,
 167                spread, rq0_min_vruntime, spread0;
 168        struct rq *rq = cpu_rq(cpu);
 169        struct sched_entity *last;
 170        unsigned long flags;
 171
 172#ifdef CONFIG_FAIR_GROUP_SCHED
 173        SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, task_group_path(cfs_rq->tg));
 174#else
 175        SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu);
 176#endif
 177        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "exec_clock",
 178                        SPLIT_NS(cfs_rq->exec_clock));
 179
 180        raw_spin_lock_irqsave(&rq->lock, flags);
 181        if (cfs_rq->rb_leftmost)
 182                MIN_vruntime = (__pick_first_entity(cfs_rq))->vruntime;
 183        last = __pick_last_entity(cfs_rq);
 184        if (last)
 185                max_vruntime = last->vruntime;
 186        min_vruntime = cfs_rq->min_vruntime;
 187        rq0_min_vruntime = cpu_rq(0)->cfs.min_vruntime;
 188        raw_spin_unlock_irqrestore(&rq->lock, flags);
 189        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "MIN_vruntime",
 190                        SPLIT_NS(MIN_vruntime));
 191        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "min_vruntime",
 192                        SPLIT_NS(min_vruntime));
 193        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "max_vruntime",
 194                        SPLIT_NS(max_vruntime));
 195        spread = max_vruntime - MIN_vruntime;
 196        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread",
 197                        SPLIT_NS(spread));
 198        spread0 = min_vruntime - rq0_min_vruntime;
 199        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread0",
 200                        SPLIT_NS(spread0));
 201        SEQ_printf(m, "  .%-30s: %d\n", "nr_spread_over",
 202                        cfs_rq->nr_spread_over);
 203        SEQ_printf(m, "  .%-30s: %ld\n", "nr_running", cfs_rq->nr_running);
 204        SEQ_printf(m, "  .%-30s: %ld\n", "load", cfs_rq->load.weight);
 205#ifdef CONFIG_FAIR_GROUP_SCHED
 206#ifdef CONFIG_SMP
 207        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "load_avg",
 208                        SPLIT_NS(cfs_rq->load_avg));
 209        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "load_period",
 210                        SPLIT_NS(cfs_rq->load_period));
 211        SEQ_printf(m, "  .%-30s: %ld\n", "load_contrib",
 212                        cfs_rq->load_contribution);
 213        SEQ_printf(m, "  .%-30s: %d\n", "load_tg",
 214                        atomic_read(&cfs_rq->tg->load_weight));
 215#endif
 216
 217        print_cfs_group_stats(m, cpu, cfs_rq->tg);
 218#endif
 219}
 220
 221void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
 222{
 223#ifdef CONFIG_RT_GROUP_SCHED
 224        SEQ_printf(m, "\nrt_rq[%d]:%s\n", cpu, task_group_path(rt_rq->tg));
 225#else
 226        SEQ_printf(m, "\nrt_rq[%d]:\n", cpu);
 227#endif
 228
 229#define P(x) \
 230        SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rt_rq->x))
 231#define PN(x) \
 232        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x))
 233
 234        P(rt_nr_running);
 235        P(rt_throttled);
 236        PN(rt_time);
 237        PN(rt_runtime);
 238
 239#undef PN
 240#undef P
 241}
 242
 243extern __read_mostly int sched_clock_running;
 244
 245static void print_cpu(struct seq_file *m, int cpu)
 246{
 247        struct rq *rq = cpu_rq(cpu);
 248        unsigned long flags;
 249
 250#ifdef CONFIG_X86
 251        {
 252                unsigned int freq = cpu_khz ? : 1;
 253
 254                SEQ_printf(m, "\ncpu#%d, %u.%03u MHz\n",
 255                           cpu, freq / 1000, (freq % 1000));
 256        }
 257#else
 258        SEQ_printf(m, "\ncpu#%d\n", cpu);
 259#endif
 260
 261#define P(x) \
 262        SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rq->x))
 263#define PN(x) \
 264        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rq->x))
 265
 266        P(nr_running);
 267        SEQ_printf(m, "  .%-30s: %lu\n", "load",
 268                   rq->load.weight);
 269        P(nr_switches);
 270        P(nr_load_updates);
 271        P(nr_uninterruptible);
 272        PN(next_balance);
 273        P(curr->pid);
 274        PN(clock);
 275        P(cpu_load[0]);
 276        P(cpu_load[1]);
 277        P(cpu_load[2]);
 278        P(cpu_load[3]);
 279        P(cpu_load[4]);
 280#undef P
 281#undef PN
 282
 283#ifdef CONFIG_SCHEDSTATS
 284#define P(n) SEQ_printf(m, "  .%-30s: %d\n", #n, rq->n);
 285#define P64(n) SEQ_printf(m, "  .%-30s: %Ld\n", #n, rq->n);
 286
 287        P(yld_count);
 288
 289        P(sched_switch);
 290        P(sched_count);
 291        P(sched_goidle);
 292#ifdef CONFIG_SMP
 293        P64(avg_idle);
 294#endif
 295
 296        P(ttwu_count);
 297        P(ttwu_local);
 298
 299#undef P
 300#undef P64
 301#endif
 302        spin_lock_irqsave(&sched_debug_lock, flags);
 303        print_cfs_stats(m, cpu);
 304        print_rt_stats(m, cpu);
 305
 306        rcu_read_lock();
 307        print_rq(m, rq, cpu);
 308        rcu_read_unlock();
 309        spin_unlock_irqrestore(&sched_debug_lock, flags);
 310}
 311
 312static const char *sched_tunable_scaling_names[] = {
 313        "none",
 314        "logaritmic",
 315        "linear"
 316};
 317
 318static int sched_debug_show(struct seq_file *m, void *v)
 319{
 320        u64 ktime, sched_clk, cpu_clk;
 321        unsigned long flags;
 322        int cpu;
 323
 324        local_irq_save(flags);
 325        ktime = ktime_to_ns(ktime_get());
 326        sched_clk = sched_clock();
 327        cpu_clk = local_clock();
 328        local_irq_restore(flags);
 329
 330        SEQ_printf(m, "Sched Debug Version: v0.10, %s %.*s\n",
 331                init_utsname()->release,
 332                (int)strcspn(init_utsname()->version, " "),
 333                init_utsname()->version);
 334
 335#define P(x) \
 336        SEQ_printf(m, "%-40s: %Ld\n", #x, (long long)(x))
 337#define PN(x) \
 338        SEQ_printf(m, "%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
 339        PN(ktime);
 340        PN(sched_clk);
 341        PN(cpu_clk);
 342        P(jiffies);
 343#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
 344        P(sched_clock_stable);
 345#endif
 346#undef PN
 347#undef P
 348
 349        SEQ_printf(m, "\n");
 350        SEQ_printf(m, "sysctl_sched\n");
 351
 352#define P(x) \
 353        SEQ_printf(m, "  .%-40s: %Ld\n", #x, (long long)(x))
 354#define PN(x) \
 355        SEQ_printf(m, "  .%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
 356        PN(sysctl_sched_latency);
 357        PN(sysctl_sched_min_granularity);
 358        PN(sysctl_sched_wakeup_granularity);
 359        P(sysctl_sched_child_runs_first);
 360        P(sysctl_sched_features);
 361#undef PN
 362#undef P
 363
 364        SEQ_printf(m, "  .%-40s: %d (%s)\n", "sysctl_sched_tunable_scaling",
 365                sysctl_sched_tunable_scaling,
 366                sched_tunable_scaling_names[sysctl_sched_tunable_scaling]);
 367
 368        for_each_online_cpu(cpu)
 369                print_cpu(m, cpu);
 370
 371        SEQ_printf(m, "\n");
 372
 373        return 0;
 374}
 375
 376static void sysrq_sched_debug_show(void)
 377{
 378        sched_debug_show(NULL, NULL);
 379}
 380
 381static int sched_debug_open(struct inode *inode, struct file *filp)
 382{
 383        return single_open(filp, sched_debug_show, NULL);
 384}
 385
 386static const struct file_operations sched_debug_fops = {
 387        .open           = sched_debug_open,
 388        .read           = seq_read,
 389        .llseek         = seq_lseek,
 390        .release        = single_release,
 391};
 392
 393static int __init init_sched_debug_procfs(void)
 394{
 395        struct proc_dir_entry *pe;
 396
 397        pe = proc_create("sched_debug", 0444, NULL, &sched_debug_fops);
 398        if (!pe)
 399                return -ENOMEM;
 400        return 0;
 401}
 402
 403__initcall(init_sched_debug_procfs);
 404
 405void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
 406{
 407        unsigned long nr_switches;
 408
 409        SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid,
 410                                                get_nr_threads(p));
 411        SEQ_printf(m,
 412                "---------------------------------------------------------\n");
 413#define __P(F) \
 414        SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)F)
 415#define P(F) \
 416        SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)p->F)
 417#define __PN(F) \
 418        SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
 419#define PN(F) \
 420        SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
 421
 422        PN(se.exec_start);
 423        PN(se.vruntime);
 424        PN(se.sum_exec_runtime);
 425
 426        nr_switches = p->nvcsw + p->nivcsw;
 427
 428#ifdef CONFIG_SCHEDSTATS
 429        PN(se.statistics.wait_start);
 430        PN(se.statistics.sleep_start);
 431        PN(se.statistics.block_start);
 432        PN(se.statistics.sleep_max);
 433        PN(se.statistics.block_max);
 434        PN(se.statistics.exec_max);
 435        PN(se.statistics.slice_max);
 436        PN(se.statistics.wait_max);
 437        PN(se.statistics.wait_sum);
 438        P(se.statistics.wait_count);
 439        PN(se.statistics.iowait_sum);
 440        P(se.statistics.iowait_count);
 441        P(se.nr_migrations);
 442        P(se.statistics.nr_migrations_cold);
 443        P(se.statistics.nr_failed_migrations_affine);
 444        P(se.statistics.nr_failed_migrations_running);
 445        P(se.statistics.nr_failed_migrations_hot);
 446        P(se.statistics.nr_forced_migrations);
 447        P(se.statistics.nr_wakeups);
 448        P(se.statistics.nr_wakeups_sync);
 449        P(se.statistics.nr_wakeups_migrate);
 450        P(se.statistics.nr_wakeups_local);
 451        P(se.statistics.nr_wakeups_remote);
 452        P(se.statistics.nr_wakeups_affine);
 453        P(se.statistics.nr_wakeups_affine_attempts);
 454        P(se.statistics.nr_wakeups_passive);
 455        P(se.statistics.nr_wakeups_idle);
 456
 457        {
 458                u64 avg_atom, avg_per_cpu;
 459
 460                avg_atom = p->se.sum_exec_runtime;
 461                if (nr_switches)
 462                        do_div(avg_atom, nr_switches);
 463                else
 464                        avg_atom = -1LL;
 465
 466                avg_per_cpu = p->se.sum_exec_runtime;
 467                if (p->se.nr_migrations) {
 468                        avg_per_cpu = div64_u64(avg_per_cpu,
 469                                                p->se.nr_migrations);
 470                } else {
 471                        avg_per_cpu = -1LL;
 472                }
 473
 474                __PN(avg_atom);
 475                __PN(avg_per_cpu);
 476        }
 477#endif
 478        __P(nr_switches);
 479        SEQ_printf(m, "%-35s:%21Ld\n",
 480                   "nr_voluntary_switches", (long long)p->nvcsw);
 481        SEQ_printf(m, "%-35s:%21Ld\n",
 482                   "nr_involuntary_switches", (long long)p->nivcsw);
 483
 484        P(se.load.weight);
 485        P(policy);
 486        P(prio);
 487#undef PN
 488#undef __PN
 489#undef P
 490#undef __P
 491
 492        {
 493                unsigned int this_cpu = raw_smp_processor_id();
 494                u64 t0, t1;
 495
 496                t0 = cpu_clock(this_cpu);
 497                t1 = cpu_clock(this_cpu);
 498                SEQ_printf(m, "%-35s:%21Ld\n",
 499                           "clock-delta", (long long)(t1-t0));
 500        }
 501}
 502
 503void proc_sched_set_task(struct task_struct *p)
 504{
 505#ifdef CONFIG_SCHEDSTATS
 506        memset(&p->se.statistics, 0, sizeof(p->se.statistics));
 507#endif
 508}
 509
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