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
  19/*
  20 * This allows printing both to /proc/sched_debug and
  21 * to the console
  22 */
  23#define SEQ_printf(m, x...)                     \
  24 do {                                           \
  25        if (m)                                  \
  26                seq_printf(m, x);               \
  27        else                                    \
  28                printk(x);                      \
  29 } while (0)
  30
  31/*
  32 * Ease the printing of nsec fields:
  33 */
  34static long long nsec_high(unsigned long long nsec)
  35{
  36        if ((long long)nsec < 0) {
  37                nsec = -nsec;
  38                do_div(nsec, 1000000);
  39                return -nsec;
  40        }
  41        do_div(nsec, 1000000);
  42
  43        return nsec;
  44}
  45
  46static unsigned long nsec_low(unsigned long long nsec)
  47{
  48        if ((long long)nsec < 0)
  49                nsec = -nsec;
  50
  51        return do_div(nsec, 1000000);
  52}
  53
  54#define SPLIT_NS(x) nsec_high(x), nsec_low(x)
  55
  56#ifdef CONFIG_FAIR_GROUP_SCHED
  57static void print_cfs_group_stats(struct seq_file *m, int cpu,
  58                struct task_group *tg)
  59{
  60        struct sched_entity *se = tg->se[cpu];
  61        if (!se)
  62                return;
  63
  64#define P(F) \
  65        SEQ_printf(m, "  .%-30s: %lld\n", #F, (long long)F)
  66#define PN(F) \
  67        SEQ_printf(m, "  .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F))
  68
  69        PN(se->exec_start);
  70        PN(se->vruntime);
  71        PN(se->sum_exec_runtime);
  72#ifdef CONFIG_SCHEDSTATS
  73        PN(se->statistics.wait_start);
  74        PN(se->statistics.sleep_start);
  75        PN(se->statistics.block_start);
  76        PN(se->statistics.sleep_max);
  77        PN(se->statistics.block_max);
  78        PN(se->statistics.exec_max);
  79        PN(se->statistics.slice_max);
  80        PN(se->statistics.wait_max);
  81        PN(se->statistics.wait_sum);
  82        P(se->statistics.wait_count);
  83#endif
  84        P(se->load.weight);
  85#undef PN
  86#undef P
  87}
  88#endif
  89
  90static void
  91print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
  92{
  93        if (rq->curr == p)
  94                SEQ_printf(m, "R");
  95        else
  96                SEQ_printf(m, " ");
  97
  98        SEQ_printf(m, "%15s %5d %9Ld.%06ld %9Ld %5d ",
  99                p->comm, p->pid,
 100                SPLIT_NS(p->se.vruntime),
 101                (long long)(p->nvcsw + p->nivcsw),
 102                p->prio);
 103#ifdef CONFIG_SCHEDSTATS
 104        SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
 105                SPLIT_NS(p->se.vruntime),
 106                SPLIT_NS(p->se.sum_exec_runtime),
 107                SPLIT_NS(p->se.statistics.sum_sleep_runtime));
 108#else
 109        SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld",
 110                0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L);
 111#endif
 112
 113#ifdef CONFIG_CGROUP_SCHED
 114        {
 115                char path[64];
 116
 117                rcu_read_lock();
 118                cgroup_path(task_group(p)->css.cgroup, path, sizeof(path));
 119                rcu_read_unlock();
 120                SEQ_printf(m, " %s", path);
 121        }
 122#endif
 123        SEQ_printf(m, "\n");
 124}
 125
 126static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
 127{
 128        struct task_struct *g, *p;
 129        unsigned long flags;
 130
 131        SEQ_printf(m,
 132        "\nrunnable tasks:\n"
 133        "            task   PID         tree-key  switches  prio"
 134        "     exec-runtime         sum-exec        sum-sleep\n"
 135        "------------------------------------------------------"
 136        "----------------------------------------------------\n");
 137
 138        read_lock_irqsave(&tasklist_lock, flags);
 139
 140        do_each_thread(g, p) {
 141                if (!p->se.on_rq || task_cpu(p) != rq_cpu)
 142                        continue;
 143
 144                print_task(m, rq, p);
 145        } while_each_thread(g, p);
 146
 147        read_unlock_irqrestore(&tasklist_lock, flags);
 148}
 149
 150#if defined(CONFIG_CGROUP_SCHED) && \
 151        (defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED))
 152static void task_group_path(struct task_group *tg, char *buf, int buflen)
 153{
 154        /* may be NULL if the underlying cgroup isn't fully-created yet */
 155        if (!tg->css.cgroup) {
 156                buf[0] = '\0';
 157                return;
 158        }
 159        cgroup_path(tg->css.cgroup, buf, buflen);
 160}
 161#endif
 162
 163void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 164{
 165        s64 MIN_vruntime = -1, min_vruntime, max_vruntime = -1,
 166                spread, rq0_min_vruntime, spread0;
 167        struct rq *rq = cpu_rq(cpu);
 168        struct sched_entity *last;
 169        unsigned long flags;
 170
 171#if defined(CONFIG_CGROUP_SCHED) && defined(CONFIG_FAIR_GROUP_SCHED)
 172        char path[128];
 173        struct task_group *tg = cfs_rq->tg;
 174
 175        task_group_path(tg, path, sizeof(path));
 176
 177        SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, path);
 178#else
 179        SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu);
 180#endif
 181        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "exec_clock",
 182                        SPLIT_NS(cfs_rq->exec_clock));
 183
 184        raw_spin_lock_irqsave(&rq->lock, flags);
 185        if (cfs_rq->rb_leftmost)
 186                MIN_vruntime = (__pick_next_entity(cfs_rq))->vruntime;
 187        last = __pick_last_entity(cfs_rq);
 188        if (last)
 189                max_vruntime = last->vruntime;
 190        min_vruntime = cfs_rq->min_vruntime;
 191        rq0_min_vruntime = cpu_rq(0)->cfs.min_vruntime;
 192        raw_spin_unlock_irqrestore(&rq->lock, flags);
 193        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "MIN_vruntime",
 194                        SPLIT_NS(MIN_vruntime));
 195        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "min_vruntime",
 196                        SPLIT_NS(min_vruntime));
 197        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "max_vruntime",
 198                        SPLIT_NS(max_vruntime));
 199        spread = max_vruntime - MIN_vruntime;
 200        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread",
 201                        SPLIT_NS(spread));
 202        spread0 = min_vruntime - rq0_min_vruntime;
 203        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread0",
 204                        SPLIT_NS(spread0));
 205        SEQ_printf(m, "  .%-30s: %ld\n", "nr_running", cfs_rq->nr_running);
 206        SEQ_printf(m, "  .%-30s: %ld\n", "load", cfs_rq->load.weight);
 207
 208        SEQ_printf(m, "  .%-30s: %d\n", "nr_spread_over",
 209                        cfs_rq->nr_spread_over);
 210#ifdef CONFIG_FAIR_GROUP_SCHED
 211#ifdef CONFIG_SMP
 212        SEQ_printf(m, "  .%-30s: %lu\n", "shares", cfs_rq->shares);
 213#endif
 214        print_cfs_group_stats(m, cpu, cfs_rq->tg);
 215#endif
 216}
 217
 218void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
 219{
 220#if defined(CONFIG_CGROUP_SCHED) && defined(CONFIG_RT_GROUP_SCHED)
 221        char path[128];
 222        struct task_group *tg = rt_rq->tg;
 223
 224        task_group_path(tg, path, sizeof(path));
 225
 226        SEQ_printf(m, "\nrt_rq[%d]:%s\n", cpu, path);
 227#else
 228        SEQ_printf(m, "\nrt_rq[%d]:\n", cpu);
 229#endif
 230
 231
 232#define P(x) \
 233        SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rt_rq->x))
 234#define PN(x) \
 235        SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x))
 236
 237        P(rt_nr_running);
 238        P(rt_throttled);
 239        PN(rt_time);
 240        PN(rt_runtime);
 241
 242#undef PN
 243#undef P
 244}
 245
 246static void print_cpu(struct seq_file *m, int cpu)
 247{
 248        struct rq *rq = cpu_rq(cpu);
 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        P(bkl_count);
 300
 301#undef P
 302#endif
 303        print_cfs_stats(m, cpu);
 304        print_rt_stats(m, cpu);
 305
 306        print_rq(m, rq, cpu);
 307}
 308
 309static const char *sched_tunable_scaling_names[] = {
 310        "none",
 311        "logaritmic",
 312        "linear"
 313};
 314
 315static int sched_debug_show(struct seq_file *m, void *v)
 316{
 317        u64 now = ktime_to_ns(ktime_get());
 318        int cpu;
 319
 320        SEQ_printf(m, "Sched Debug Version: v0.09, %s %.*s\n",
 321                init_utsname()->release,
 322                (int)strcspn(init_utsname()->version, " "),
 323                init_utsname()->version);
 324
 325        SEQ_printf(m, "now at %Lu.%06ld msecs\n", SPLIT_NS(now));
 326
 327#define P(x) \
 328        SEQ_printf(m, "  .%-40s: %Ld\n", #x, (long long)(x))
 329#define PN(x) \
 330        SEQ_printf(m, "  .%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
 331        P(jiffies);
 332        PN(sysctl_sched_latency);
 333        PN(sysctl_sched_min_granularity);
 334        PN(sysctl_sched_wakeup_granularity);
 335        P(sysctl_sched_child_runs_first);
 336        P(sysctl_sched_features);
 337#undef PN
 338#undef P
 339
 340        SEQ_printf(m, "  .%-40s: %d (%s)\n", "sysctl_sched_tunable_scaling",
 341                sysctl_sched_tunable_scaling,
 342                sched_tunable_scaling_names[sysctl_sched_tunable_scaling]);
 343
 344        for_each_online_cpu(cpu)
 345                print_cpu(m, cpu);
 346
 347        SEQ_printf(m, "\n");
 348
 349        return 0;
 350}
 351
 352static void sysrq_sched_debug_show(void)
 353{
 354        sched_debug_show(NULL, NULL);
 355}
 356
 357static int sched_debug_open(struct inode *inode, struct file *filp)
 358{
 359        return single_open(filp, sched_debug_show, NULL);
 360}
 361
 362static const struct file_operations sched_debug_fops = {
 363        .open           = sched_debug_open,
 364        .read           = seq_read,
 365        .llseek         = seq_lseek,
 366        .release        = single_release,
 367};
 368
 369static int __init init_sched_debug_procfs(void)
 370{
 371        struct proc_dir_entry *pe;
 372
 373        pe = proc_create("sched_debug", 0444, NULL, &sched_debug_fops);
 374        if (!pe)
 375                return -ENOMEM;
 376        return 0;
 377}
 378
 379__initcall(init_sched_debug_procfs);
 380
 381void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
 382{
 383        unsigned long nr_switches;
 384
 385        SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid,
 386                                                get_nr_threads(p));
 387        SEQ_printf(m,
 388                "---------------------------------------------------------\n");
 389#define __P(F) \
 390        SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)F)
 391#define P(F) \
 392        SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)p->F)
 393#define __PN(F) \
 394        SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
 395#define PN(F) \
 396        SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
 397
 398        PN(se.exec_start);
 399        PN(se.vruntime);
 400        PN(se.sum_exec_runtime);
 401
 402        nr_switches = p->nvcsw + p->nivcsw;
 403
 404#ifdef CONFIG_SCHEDSTATS
 405        PN(se.statistics.wait_start);
 406        PN(se.statistics.sleep_start);
 407        PN(se.statistics.block_start);
 408        PN(se.statistics.sleep_max);
 409        PN(se.statistics.block_max);
 410        PN(se.statistics.exec_max);
 411        PN(se.statistics.slice_max);
 412        PN(se.statistics.wait_max);
 413        PN(se.statistics.wait_sum);
 414        P(se.statistics.wait_count);
 415        PN(se.statistics.iowait_sum);
 416        P(se.statistics.iowait_count);
 417        P(sched_info.bkl_count);
 418        P(se.nr_migrations);
 419        P(se.statistics.nr_migrations_cold);
 420        P(se.statistics.nr_failed_migrations_affine);
 421        P(se.statistics.nr_failed_migrations_running);
 422        P(se.statistics.nr_failed_migrations_hot);
 423        P(se.statistics.nr_forced_migrations);
 424        P(se.statistics.nr_wakeups);
 425        P(se.statistics.nr_wakeups_sync);
 426        P(se.statistics.nr_wakeups_migrate);
 427        P(se.statistics.nr_wakeups_local);
 428        P(se.statistics.nr_wakeups_remote);
 429        P(se.statistics.nr_wakeups_affine);
 430        P(se.statistics.nr_wakeups_affine_attempts);
 431        P(se.statistics.nr_wakeups_passive);
 432        P(se.statistics.nr_wakeups_idle);
 433
 434        {
 435                u64 avg_atom, avg_per_cpu;
 436
 437                avg_atom = p->se.sum_exec_runtime;
 438                if (nr_switches)
 439                        do_div(avg_atom, nr_switches);
 440                else
 441                        avg_atom = -1LL;
 442
 443                avg_per_cpu = p->se.sum_exec_runtime;
 444                if (p->se.nr_migrations) {
 445                        avg_per_cpu = div64_u64(avg_per_cpu,
 446                                                p->se.nr_migrations);
 447                } else {
 448                        avg_per_cpu = -1LL;
 449                }
 450
 451                __PN(avg_atom);
 452                __PN(avg_per_cpu);
 453        }
 454#endif
 455        __P(nr_switches);
 456        SEQ_printf(m, "%-35s:%21Ld\n",
 457                   "nr_voluntary_switches", (long long)p->nvcsw);
 458        SEQ_printf(m, "%-35s:%21Ld\n",
 459                   "nr_involuntary_switches", (long long)p->nivcsw);
 460
 461        P(se.load.weight);
 462        P(policy);
 463        P(prio);
 464#undef PN
 465#undef __PN
 466#undef P
 467#undef __P
 468
 469        {
 470                unsigned int this_cpu = raw_smp_processor_id();
 471                u64 t0, t1;
 472
 473                t0 = cpu_clock(this_cpu);
 474                t1 = cpu_clock(this_cpu);
 475                SEQ_printf(m, "%-35s:%21Ld\n",
 476                           "clock-delta", (long long)(t1-t0));
 477        }
 478}
 479
 480void proc_sched_set_task(struct task_struct *p)
 481{
 482#ifdef CONFIG_SCHEDSTATS
 483        memset(&p->se.statistics, 0, sizeof(p->se.statistics));
 484#endif
 485}
 486