linux/kernel/sched/debug.c
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   1/*
   2 * kernel/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
  19#include "sched.h"
  20
  21static DEFINE_SPINLOCK(sched_debug_lock);
  22
  23/*
  24 * This allows printing both to /proc/sched_debug and
  25 * to the console
  26 */
  27#define SEQ_printf(m, x...)                     \
  28 do {                                           \
  29        if (m)                                  \
  30                seq_printf(m, x);               \
  31        else                                    \
  32                printk(x);                      \
  33 } while (0)
  34
  35/*
  36 * Ease the printing of nsec fields:
  37 */
  38static long long nsec_high(unsigned long long nsec)
  39{
  40        if ((long long)nsec < 0) {
  41                nsec = -nsec;
  42                do_div(nsec, 1000000);
  43                return -nsec;
  44        }
  45        do_div(nsec, 1000000);
  46
  47        return nsec;
  48}
  49
  50static unsigned long nsec_low(unsigned long long nsec)
  51{
  52        if ((long long)nsec < 0)
  53                nsec = -nsec;
  54
  55        return do_div(nsec, 1000000);
  56}
  57
  58#define SPLIT_NS(x) nsec_high(x), nsec_low(x)
  59
  60#ifdef CONFIG_FAIR_GROUP_SCHED
  61static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group *tg)
  62{
  63        struct sched_entity *se = tg->se[cpu];
  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        if (!se) {
  71                struct sched_avg *avg = &cpu_rq(cpu)->avg;
  72                P(avg->runnable_avg_sum);
  73                P(avg->runnable_avg_period);
  74                return;
  75        }
  76
  77
  78        PN(se->exec_start);
  79        PN(se->vruntime);
  80        PN(se->sum_exec_runtime);
  81#ifdef CONFIG_SCHEDSTATS
  82        PN(se->statistics.wait_start);
  83        PN(se->statistics.sleep_start);
  84        PN(se->statistics.block_start);
  85        PN(se->statistics.sleep_max);
  86        PN(se->statistics.block_max);
  87        PN(se->statistics.exec_max);
  88        PN(se->statistics.slice_max);
  89        PN(se->statistics.wait_max);
  90        PN(se->statistics.wait_sum);
  91        P(se->statistics.wait_count);
  92#endif
  93        P(se->load.weight);
  94#ifdef CONFIG_SMP
  95        P(se->avg.runnable_avg_sum);
  96        P(se->avg.runnable_avg_period);
  97        P(se->avg.load_avg_contrib);
  98        P(se->avg.decay_count);
  99#endif
 100#undef PN
 101#undef P
 102}
 103#endif
 104
 105#ifdef CONFIG_CGROUP_SCHED
 106static char group_path[PATH_MAX];
 107
 108static char *task_group_path(struct task_group *tg)
 109{
 110        if (autogroup_path(tg, group_path, PATH_MAX))
 111                return group_path;
 112
 113        cgroup_path(tg->css.cgroup, group_path, PATH_MAX);
 114        return group_path;
 115}
 116#endif
 117
 118static void
 119print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
 120{
 121        if (rq->curr == p)
 122                SEQ_printf(m, "R");
 123        else
 124                SEQ_printf(m, " ");
 125
 126        SEQ_printf(m, "%15s %5d %9Ld.%06ld %9Ld %5d ",
 127                p->comm, p->pid,
 128                SPLIT_NS(p->se.vruntime),
 129                (long long)(p->nvcsw + p->nivcsw),
 130                p->prio);
 131#ifdef CONFIG_SCHEDSTATS
 132        SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
 133                SPLIT_NS(p->se.vruntime),
 134                SPLIT_NS(p->se.sum_exec_runtime),
 135                SPLIT_NS(p->se.statistics.sum_sleep_runtime));
 136#else
 137        SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld",
 138                0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L);
 139#endif
 140#ifdef CONFIG_CGROUP_SCHED
 141        SEQ_printf(m, " %s", task_group_path(task_group(p)));
 142#endif
 143
 144        SEQ_printf(m, "\n");
 145}
 146
 147static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
 148{
 149        struct task_struct *g, *p;
 150        unsigned long flags;
 151
 152        SEQ_printf(m,
 153        "\nrunnable tasks:\n"
 154        "            task   PID         tree-key  switches  prio"
 155        "     exec-runtime         sum-exec        sum-sleep\n"
 156        "------------------------------------------------------"
 157        "----------------------------------------------------\n");
 158
 159        read_lock_irqsave(&tasklist_lock, flags);
 160
 161        do_each_thread(g, p) {
 162                if (!p->on_rq || task_cpu(p) != rq_cpu)
 163                        continue;
 164
 165                print_task(m, rq, p);
 166        } while_each_thread(g, p);
 167
 168        read_unlock_irqrestore(&tasklist_lock, flags);
 169}
 170
 171void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 172{
 173        s64 MIN_vruntime = -1, min_vruntime, max_vruntime = -1,
 174                spread, rq0_min_vruntime, spread0;
 175        struct rq *rq = cpu_rq(cpu);
 176        struct sched_entity *last;
 177        unsigned long flags;
 178
 179#ifdef CONFIG_FAIR_GROUP_SCHED
 180        SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, task_group_path(cfs_rq->tg));
 181#else
 182        SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu);
 183#endif
 184        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "exec_clock",
 185                        SPLIT_NS(cfs_rq->exec_clock));
 186
 187        raw_spin_lock_irqsave(&rq->lock, flags);
 188        if (cfs_rq->rb_leftmost)
 189                MIN_vruntime = (__pick_first_entity(cfs_rq))->vruntime;
 190        last = __pick_last_entity(cfs_rq);
 191        if (last)
 192                max_vruntime = last->vruntime;
 193        min_vruntime = cfs_rq->min_vruntime;
 194        rq0_min_vruntime = cpu_rq(0)->cfs.min_vruntime;
 195        raw_spin_unlock_irqrestore(&rq->lock, flags);
 196        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "MIN_vruntime",
 197                        SPLIT_NS(MIN_vruntime));
 198        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "min_vruntime",
 199                        SPLIT_NS(min_vruntime));
 200        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "max_vruntime",
 201                        SPLIT_NS(max_vruntime));
 202        spread = max_vruntime - MIN_vruntime;
 203        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread",
 204                        SPLIT_NS(spread));
 205        spread0 = min_vruntime - rq0_min_vruntime;
 206        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread0",
 207                        SPLIT_NS(spread0));
 208        SEQ_printf(m, "  .%-30s: %d\n", "nr_spread_over",
 209                        cfs_rq->nr_spread_over);
 210        SEQ_printf(m, "  .%-30s: %d\n", "nr_running", cfs_rq->nr_running);
 211        SEQ_printf(m, "  .%-30s: %ld\n", "load", cfs_rq->load.weight);
 212#ifdef CONFIG_SMP
 213        SEQ_printf(m, "  .%-30s: %ld\n", "runnable_load_avg",
 214                        cfs_rq->runnable_load_avg);
 215        SEQ_printf(m, "  .%-30s: %ld\n", "blocked_load_avg",
 216                        cfs_rq->blocked_load_avg);
 217#ifdef CONFIG_FAIR_GROUP_SCHED
 218        SEQ_printf(m, "  .%-30s: %ld\n", "tg_load_contrib",
 219                        cfs_rq->tg_load_contrib);
 220        SEQ_printf(m, "  .%-30s: %d\n", "tg_runnable_contrib",
 221                        cfs_rq->tg_runnable_contrib);
 222        SEQ_printf(m, "  .%-30s: %ld\n", "tg_load_avg",
 223                        atomic_long_read(&cfs_rq->tg->load_avg));
 224        SEQ_printf(m, "  .%-30s: %d\n", "tg->runnable_avg",
 225                        atomic_read(&cfs_rq->tg->runnable_avg));
 226#endif
 227#endif
 228
 229#ifdef CONFIG_FAIR_GROUP_SCHED
 230        print_cfs_group_stats(m, cpu, cfs_rq->tg);
 231#endif
 232}
 233
 234void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
 235{
 236#ifdef CONFIG_RT_GROUP_SCHED
 237        SEQ_printf(m, "\nrt_rq[%d]:%s\n", cpu, task_group_path(rt_rq->tg));
 238#else
 239        SEQ_printf(m, "\nrt_rq[%d]:\n", cpu);
 240#endif
 241
 242#define P(x) \
 243        SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rt_rq->x))
 244#define PN(x) \
 245        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x))
 246
 247        P(rt_nr_running);
 248        P(rt_throttled);
 249        PN(rt_time);
 250        PN(rt_runtime);
 251
 252#undef PN
 253#undef P
 254}
 255
 256extern __read_mostly int sched_clock_running;
 257
 258static void print_cpu(struct seq_file *m, int cpu)
 259{
 260        struct rq *rq = cpu_rq(cpu);
 261        unsigned long flags;
 262
 263#ifdef CONFIG_X86
 264        {
 265                unsigned int freq = cpu_khz ? : 1;
 266
 267                SEQ_printf(m, "cpu#%d, %u.%03u MHz\n",
 268                           cpu, freq / 1000, (freq % 1000));
 269        }
 270#else
 271        SEQ_printf(m, "cpu#%d\n", cpu);
 272#endif
 273
 274#define P(x)                                                            \
 275do {                                                                    \
 276        if (sizeof(rq->x) == 4)                                         \
 277                SEQ_printf(m, "  .%-30s: %ld\n", #x, (long)(rq->x));    \
 278        else                                                            \
 279                SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rq->x));\
 280} while (0)
 281
 282#define PN(x) \
 283        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rq->x))
 284
 285        P(nr_running);
 286        SEQ_printf(m, "  .%-30s: %lu\n", "load",
 287                   rq->load.weight);
 288        P(nr_switches);
 289        P(nr_load_updates);
 290        P(nr_uninterruptible);
 291        PN(next_balance);
 292        P(curr->pid);
 293        PN(clock);
 294        P(cpu_load[0]);
 295        P(cpu_load[1]);
 296        P(cpu_load[2]);
 297        P(cpu_load[3]);
 298        P(cpu_load[4]);
 299#undef P
 300#undef PN
 301
 302#ifdef CONFIG_SCHEDSTATS
 303#define P(n) SEQ_printf(m, "  .%-30s: %d\n", #n, rq->n);
 304#define P64(n) SEQ_printf(m, "  .%-30s: %Ld\n", #n, rq->n);
 305
 306        P(yld_count);
 307
 308        P(sched_count);
 309        P(sched_goidle);
 310#ifdef CONFIG_SMP
 311        P64(avg_idle);
 312#endif
 313
 314        P(ttwu_count);
 315        P(ttwu_local);
 316
 317#undef P
 318#undef P64
 319#endif
 320        spin_lock_irqsave(&sched_debug_lock, flags);
 321        print_cfs_stats(m, cpu);
 322        print_rt_stats(m, cpu);
 323
 324        rcu_read_lock();
 325        print_rq(m, rq, cpu);
 326        rcu_read_unlock();
 327        spin_unlock_irqrestore(&sched_debug_lock, flags);
 328        SEQ_printf(m, "\n");
 329}
 330
 331static const char *sched_tunable_scaling_names[] = {
 332        "none",
 333        "logaritmic",
 334        "linear"
 335};
 336
 337static void sched_debug_header(struct seq_file *m)
 338{
 339        u64 ktime, sched_clk, cpu_clk;
 340        unsigned long flags;
 341
 342        local_irq_save(flags);
 343        ktime = ktime_to_ns(ktime_get());
 344        sched_clk = sched_clock();
 345        cpu_clk = local_clock();
 346        local_irq_restore(flags);
 347
 348        SEQ_printf(m, "Sched Debug Version: v0.10, %s %.*s\n",
 349                init_utsname()->release,
 350                (int)strcspn(init_utsname()->version, " "),
 351                init_utsname()->version);
 352
 353#define P(x) \
 354        SEQ_printf(m, "%-40s: %Ld\n", #x, (long long)(x))
 355#define PN(x) \
 356        SEQ_printf(m, "%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
 357        PN(ktime);
 358        PN(sched_clk);
 359        PN(cpu_clk);
 360        P(jiffies);
 361#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
 362        P(sched_clock_stable);
 363#endif
 364#undef PN
 365#undef P
 366
 367        SEQ_printf(m, "\n");
 368        SEQ_printf(m, "sysctl_sched\n");
 369
 370#define P(x) \
 371        SEQ_printf(m, "  .%-40s: %Ld\n", #x, (long long)(x))
 372#define PN(x) \
 373        SEQ_printf(m, "  .%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
 374        PN(sysctl_sched_latency);
 375        PN(sysctl_sched_min_granularity);
 376        PN(sysctl_sched_wakeup_granularity);
 377        P(sysctl_sched_child_runs_first);
 378        P(sysctl_sched_features);
 379#undef PN
 380#undef P
 381
 382        SEQ_printf(m, "  .%-40s: %d (%s)\n",
 383                "sysctl_sched_tunable_scaling",
 384                sysctl_sched_tunable_scaling,
 385                sched_tunable_scaling_names[sysctl_sched_tunable_scaling]);
 386        SEQ_printf(m, "\n");
 387}
 388
 389static int sched_debug_show(struct seq_file *m, void *v)
 390{
 391        int cpu = (unsigned long)(v - 2);
 392
 393        if (cpu != -1)
 394                print_cpu(m, cpu);
 395        else
 396                sched_debug_header(m);
 397
 398        return 0;
 399}
 400
 401void sysrq_sched_debug_show(void)
 402{
 403        int cpu;
 404
 405        sched_debug_header(NULL);
 406        for_each_online_cpu(cpu)
 407                print_cpu(NULL, cpu);
 408
 409}
 410
 411/*
 412 * This itererator needs some explanation.
 413 * It returns 1 for the header position.
 414 * This means 2 is cpu 0.
 415 * In a hotplugged system some cpus, including cpu 0, may be missing so we have
 416 * to use cpumask_* to iterate over the cpus.
 417 */
 418static void *sched_debug_start(struct seq_file *file, loff_t *offset)
 419{
 420        unsigned long n = *offset;
 421
 422        if (n == 0)
 423                return (void *) 1;
 424
 425        n--;
 426
 427        if (n > 0)
 428                n = cpumask_next(n - 1, cpu_online_mask);
 429        else
 430                n = cpumask_first(cpu_online_mask);
 431
 432        *offset = n + 1;
 433
 434        if (n < nr_cpu_ids)
 435                return (void *)(unsigned long)(n + 2);
 436        return NULL;
 437}
 438
 439static void *sched_debug_next(struct seq_file *file, void *data, loff_t *offset)
 440{
 441        (*offset)++;
 442        return sched_debug_start(file, offset);
 443}
 444
 445static void sched_debug_stop(struct seq_file *file, void *data)
 446{
 447}
 448
 449static const struct seq_operations sched_debug_sops = {
 450        .start = sched_debug_start,
 451        .next = sched_debug_next,
 452        .stop = sched_debug_stop,
 453        .show = sched_debug_show,
 454};
 455
 456static int sched_debug_release(struct inode *inode, struct file *file)
 457{
 458        seq_release(inode, file);
 459
 460        return 0;
 461}
 462
 463static int sched_debug_open(struct inode *inode, struct file *filp)
 464{
 465        int ret = 0;
 466
 467        ret = seq_open(filp, &sched_debug_sops);
 468
 469        return ret;
 470}
 471
 472static const struct file_operations sched_debug_fops = {
 473        .open           = sched_debug_open,
 474        .read           = seq_read,
 475        .llseek         = seq_lseek,
 476        .release        = sched_debug_release,
 477};
 478
 479static int __init init_sched_debug_procfs(void)
 480{
 481        struct proc_dir_entry *pe;
 482
 483        pe = proc_create("sched_debug", 0444, NULL, &sched_debug_fops);
 484        if (!pe)
 485                return -ENOMEM;
 486        return 0;
 487}
 488
 489__initcall(init_sched_debug_procfs);
 490
 491void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
 492{
 493        unsigned long nr_switches;
 494
 495        SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid,
 496                                                get_nr_threads(p));
 497        SEQ_printf(m,
 498                "---------------------------------------------------------"
 499                "----------\n");
 500#define __P(F) \
 501        SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)F)
 502#define P(F) \
 503        SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)p->F)
 504#define __PN(F) \
 505        SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
 506#define PN(F) \
 507        SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
 508
 509        PN(se.exec_start);
 510        PN(se.vruntime);
 511        PN(se.sum_exec_runtime);
 512
 513        nr_switches = p->nvcsw + p->nivcsw;
 514
 515#ifdef CONFIG_SCHEDSTATS
 516        PN(se.statistics.wait_start);
 517        PN(se.statistics.sleep_start);
 518        PN(se.statistics.block_start);
 519        PN(se.statistics.sleep_max);
 520        PN(se.statistics.block_max);
 521        PN(se.statistics.exec_max);
 522        PN(se.statistics.slice_max);
 523        PN(se.statistics.wait_max);
 524        PN(se.statistics.wait_sum);
 525        P(se.statistics.wait_count);
 526        PN(se.statistics.iowait_sum);
 527        P(se.statistics.iowait_count);
 528        P(se.nr_migrations);
 529        P(se.statistics.nr_migrations_cold);
 530        P(se.statistics.nr_failed_migrations_affine);
 531        P(se.statistics.nr_failed_migrations_running);
 532        P(se.statistics.nr_failed_migrations_hot);
 533        P(se.statistics.nr_forced_migrations);
 534        P(se.statistics.nr_wakeups);
 535        P(se.statistics.nr_wakeups_sync);
 536        P(se.statistics.nr_wakeups_migrate);
 537        P(se.statistics.nr_wakeups_local);
 538        P(se.statistics.nr_wakeups_remote);
 539        P(se.statistics.nr_wakeups_affine);
 540        P(se.statistics.nr_wakeups_affine_attempts);
 541        P(se.statistics.nr_wakeups_passive);
 542        P(se.statistics.nr_wakeups_idle);
 543
 544        {
 545                u64 avg_atom, avg_per_cpu;
 546
 547                avg_atom = p->se.sum_exec_runtime;
 548                if (nr_switches)
 549                        do_div(avg_atom, nr_switches);
 550                else
 551                        avg_atom = -1LL;
 552
 553                avg_per_cpu = p->se.sum_exec_runtime;
 554                if (p->se.nr_migrations) {
 555                        avg_per_cpu = div64_u64(avg_per_cpu,
 556                                                p->se.nr_migrations);
 557                } else {
 558                        avg_per_cpu = -1LL;
 559                }
 560
 561                __PN(avg_atom);
 562                __PN(avg_per_cpu);
 563        }
 564#endif
 565        __P(nr_switches);
 566        SEQ_printf(m, "%-45s:%21Ld\n",
 567                   "nr_voluntary_switches", (long long)p->nvcsw);
 568        SEQ_printf(m, "%-45s:%21Ld\n",
 569                   "nr_involuntary_switches", (long long)p->nivcsw);
 570
 571        P(se.load.weight);
 572#ifdef CONFIG_SMP
 573        P(se.avg.runnable_avg_sum);
 574        P(se.avg.runnable_avg_period);
 575        P(se.avg.load_avg_contrib);
 576        P(se.avg.decay_count);
 577#endif
 578        P(policy);
 579        P(prio);
 580#undef PN
 581#undef __PN
 582#undef P
 583#undef __P
 584
 585        {
 586                unsigned int this_cpu = raw_smp_processor_id();
 587                u64 t0, t1;
 588
 589                t0 = cpu_clock(this_cpu);
 590                t1 = cpu_clock(this_cpu);
 591                SEQ_printf(m, "%-45s:%21Ld\n",
 592                           "clock-delta", (long long)(t1-t0));
 593        }
 594}
 595
 596void proc_sched_set_task(struct task_struct *p)
 597{
 598#ifdef CONFIG_SCHEDSTATS
 599        memset(&p->se.statistics, 0, sizeof(p->se.statistics));
 600#endif
 601}
 602