debug.c

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/*
 * kernel/sched/debug.c
 *
 * Print the CFS rbtree
 *
 * Copyright(C) 2007, Red Hat, Inc., Ingo Molnar
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/proc_fs.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/kallsyms.h>
#include <linux/utsname.h>

#include "sched.h"

static DEFINE_SPINLOCK(sched_debug_lock);

/*
 * This allows printing both to /proc/sched_debug and
 * to the console
 */
#define SEQ_printf(m, x...)         \
 do {                       \
    if (m)                  \
        seq_printf(m, x);       \
    else                    \
        printk(x);          \
 } while (0)

/*
 * Ease the printing of nsec fields:
 */
static long long nsec_high(unsigned long long nsec)
{
    if ((long long)nsec < 0) {
        nsec = -nsec;
        do_div(nsec, 1000000);
        return -nsec;
    }
    do_div(nsec, 1000000);

    return nsec;
}

static unsigned long nsec_low(unsigned long long nsec)
{
    if ((long long)nsec < 0)
        nsec = -nsec;

    return do_div(nsec, 1000000);
}

#define SPLIT_NS(x) nsec_high(x), nsec_low(x)

#ifdef CONFIG_FAIR_GROUP_SCHED
static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group *tg)
{
    struct sched_entity *se = tg->se[cpu];
    if (!se)
        return;

#define P(F) \
    SEQ_printf(m, "  .%-30s: %lld\n", #F, (long long)F)
#define PN(F) \
    SEQ_printf(m, "  .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F))

    PN(se->exec_start);
    PN(se->vruntime);
    PN(se->sum_exec_runtime);
#ifdef CONFIG_SCHEDSTATS
    PN(se->statistics.wait_start);
    PN(se->statistics.sleep_start);
    PN(se->statistics.block_start);
    PN(se->statistics.sleep_max);
    PN(se->statistics.block_max);
    PN(se->statistics.exec_max);
    PN(se->statistics.slice_max);
    PN(se->statistics.wait_max);
    PN(se->statistics.wait_sum);
    P(se->statistics.wait_count);
#endif
    P(se->load.weight);
#undef PN
#undef P
}
#endif

#ifdef CONFIG_CGROUP_SCHED
static char group_path[PATH_MAX];

static char *task_group_path(struct task_group *tg)
{
    if (autogroup_path(tg, group_path, PATH_MAX))
        return group_path;

    /*
     * May be NULL if the underlying cgroup isn't fully-created yet
     */
    if (!tg->css.cgroup) {
        group_path[0] = '\0';
        return group_path;
    }
    cgroup_path(tg->css.cgroup, group_path, PATH_MAX);
    return group_path;
}
#endif

static void
print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
{
    if (rq->curr == p)
        SEQ_printf(m, "R");
    else
        SEQ_printf(m, " ");

    SEQ_printf(m, "%15s %5d %9Ld.%06ld %9Ld %5d ",
        p->comm, p->pid,
        SPLIT_NS(p->se.vruntime),
        (long long)(p->nvcsw + p->nivcsw),
        p->prio);
#ifdef CONFIG_SCHEDSTATS
    SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
        SPLIT_NS(p->se.vruntime),
        SPLIT_NS(p->se.sum_exec_runtime),
        SPLIT_NS(p->se.statistics.sum_sleep_runtime));
#else
    SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld",
        0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L);
#endif
#ifdef CONFIG_CGROUP_SCHED
    SEQ_printf(m, " %s", task_group_path(task_group(p)));
#endif

    SEQ_printf(m, "\n");
}

static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
{
    struct task_struct *g, *p;
    unsigned long flags;

    SEQ_printf(m,
    "\nrunnable tasks:\n"
    "            task   PID         tree-key  switches  prio"
    "     exec-runtime         sum-exec        sum-sleep\n"
    "------------------------------------------------------"
    "----------------------------------------------------\n");

    read_lock_irqsave(&tasklist_lock, flags);

    do_each_thread(g, p) {
        if (!p->on_rq || task_cpu(p) != rq_cpu)
            continue;

        print_task(m, rq, p);
    } while_each_thread(g, p);

    read_unlock_irqrestore(&tasklist_lock, flags);
}

void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
{
    s64 MIN_vruntime = -1, min_vruntime, max_vruntime = -1,
        spread, rq0_min_vruntime, spread0;
    struct rq *rq = cpu_rq(cpu);
    struct sched_entity *last;
    unsigned long flags;

#ifdef CONFIG_FAIR_GROUP_SCHED
    SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, task_group_path(cfs_rq->tg));
#else
    SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu);
#endif
    SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "exec_clock",
            SPLIT_NS(cfs_rq->exec_clock));

    raw_spin_lock_irqsave(&rq->lock, flags);
    if (cfs_rq->rb_leftmost)
        MIN_vruntime = (__pick_first_entity(cfs_rq))->vruntime;
    last = __pick_last_entity(cfs_rq);
    if (last)
        max_vruntime = last->vruntime;
    min_vruntime = cfs_rq->min_vruntime;
    rq0_min_vruntime = cpu_rq(0)->cfs.min_vruntime;
    raw_spin_unlock_irqrestore(&rq->lock, flags);
    SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "MIN_vruntime",
            SPLIT_NS(MIN_vruntime));
    SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "min_vruntime",
            SPLIT_NS(min_vruntime));
    SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "max_vruntime",
            SPLIT_NS(max_vruntime));
    spread = max_vruntime - MIN_vruntime;
    SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread",
            SPLIT_NS(spread));
    spread0 = min_vruntime - rq0_min_vruntime;
    SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread0",
            SPLIT_NS(spread0));
    SEQ_printf(m, "  .%-30s: %d\n", "nr_spread_over",
            cfs_rq->nr_spread_over);
    SEQ_printf(m, "  .%-30s: %d\n", "nr_running", cfs_rq->nr_running);
    SEQ_printf(m, "  .%-30s: %ld\n", "load", cfs_rq->load.weight);
#ifdef CONFIG_FAIR_GROUP_SCHED
#ifdef CONFIG_SMP
    SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "load_avg",
            SPLIT_NS(cfs_rq->load_avg));
    SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "load_period",
            SPLIT_NS(cfs_rq->load_period));
    SEQ_printf(m, "  .%-30s: %ld\n", "load_contrib",
            cfs_rq->load_contribution);
    SEQ_printf(m, "  .%-30s: %d\n", "load_tg",
            atomic_read(&cfs_rq->tg->load_weight));
#endif

    print_cfs_group_stats(m, cpu, cfs_rq->tg);
#endif
}

void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
{
#ifdef CONFIG_RT_GROUP_SCHED
    SEQ_printf(m, "\nrt_rq[%d]:%s\n", cpu, task_group_path(rt_rq->tg));
#else
    SEQ_printf(m, "\nrt_rq[%d]:\n", cpu);
#endif

#define P(x) \
    SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rt_rq->x))
#define PN(x) \
    SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x))

    P(rt_nr_running);
    P(rt_throttled);
    PN(rt_time);
    PN(rt_runtime);

#undef PN
#undef P
}

extern __read_mostly int sched_clock_running;

static void print_cpu(struct seq_file *m, int cpu)
{
    struct rq *rq = cpu_rq(cpu);
    unsigned long flags;

#ifdef CONFIG_X86
    {
        unsigned int freq = cpu_khz ? : 1;

        SEQ_printf(m, "\ncpu#%d, %u.%03u MHz\n",
               cpu, freq / 1000, (freq % 1000));
    }
#else
    SEQ_printf(m, "\ncpu#%d\n", cpu);
#endif

#define P(x)                                \
do {                                    \
    if (sizeof(rq->x) == 4)                     \
        SEQ_printf(m, "  .%-30s: %ld\n", #x, (long)(rq->x));    \
    else                                \
        SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rq->x));\
} while (0)

#define PN(x) \
    SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rq->x))

    P(nr_running);
    SEQ_printf(m, "  .%-30s: %lu\n", "load",
           rq->load.weight);
    P(nr_switches);
    P(nr_load_updates);
    P(nr_uninterruptible);
    PN(next_balance);
    P(curr->pid);
    PN(clock);
    P(cpu_load[0]);
    P(cpu_load[1]);
    P(cpu_load[2]);
    P(cpu_load[3]);
    P(cpu_load[4]);
#undef P
#undef PN

#ifdef CONFIG_SCHEDSTATS
#define P(n) SEQ_printf(m, "  .%-30s: %d\n", #n, rq->n);
#define P64(n) SEQ_printf(m, "  .%-30s: %Ld\n", #n, rq->n);

    P(yld_count);

    P(sched_count);
    P(sched_goidle);
#ifdef CONFIG_SMP
    P64(avg_idle);
#endif

    P(ttwu_count);
    P(ttwu_local);

#undef P
#undef P64
#endif
    spin_lock_irqsave(&sched_debug_lock, flags);
    print_cfs_stats(m, cpu);
    print_rt_stats(m, cpu);

    rcu_read_lock();
    print_rq(m, rq, cpu);
    rcu_read_unlock();
    spin_unlock_irqrestore(&sched_debug_lock, flags);
}

static const char *sched_tunable_scaling_names[] = {
    "none",
    "logaritmic",
    "linear"
};

static int sched_debug_show(struct seq_file *m, void *v)
{
    u64 ktime, sched_clk, cpu_clk;
    unsigned long flags;
    int cpu;

    local_irq_save(flags);
    ktime = ktime_to_ns(ktime_get());
    sched_clk = sched_clock();
    cpu_clk = local_clock();
    local_irq_restore(flags);

    SEQ_printf(m, "Sched Debug Version: v0.10, %s %.*s\n",
        init_utsname()->release,
        (int)strcspn(init_utsname()->version, " "),
        init_utsname()->version);

#define P(x) \
    SEQ_printf(m, "%-40s: %Ld\n", #x, (long long)(x))
#define PN(x) \
    SEQ_printf(m, "%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
    PN(ktime);
    PN(sched_clk);
    PN(cpu_clk);
    P(jiffies);
#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
    P(sched_clock_stable);
#endif
#undef PN
#undef P

    SEQ_printf(m, "\n");
    SEQ_printf(m, "sysctl_sched\n");

#define P(x) \
    SEQ_printf(m, "  .%-40s: %Ld\n", #x, (long long)(x))
#define PN(x) \
    SEQ_printf(m, "  .%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
    PN(sysctl_sched_latency);
    PN(sysctl_sched_min_granularity);
    PN(sysctl_sched_wakeup_granularity);
    P(sysctl_sched_child_runs_first);
    P(sysctl_sched_features);
#undef PN
#undef P

    SEQ_printf(m, "  .%-40s: %d (%s)\n", "sysctl_sched_tunable_scaling",
        sysctl_sched_tunable_scaling,
        sched_tunable_scaling_names[sysctl_sched_tunable_scaling]);

    for_each_online_cpu(cpu)
        print_cpu(m, cpu);

    SEQ_printf(m, "\n");

    return 0;
}

void sysrq_sched_debug_show(void)
{
    sched_debug_show(NULL, NULL);
}

static int sched_debug_open(struct inode *inode, struct file *filp)
{
    return single_open(filp, sched_debug_show, NULL);
}

static const struct file_operations sched_debug_fops = {
    .open       = sched_debug_open,
    .read       = seq_read,
    .llseek     = seq_lseek,
    .release    = single_release,
};

static int __init init_sched_debug_procfs(void)
{
    struct proc_dir_entry *pe;

    pe = proc_create("sched_debug", 0444, NULL, &sched_debug_fops);
    if (!pe)
        return -ENOMEM;
    return 0;
}

__initcall(init_sched_debug_procfs);

void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
{
    unsigned long nr_switches;

    SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid,
                        get_nr_threads(p));
    SEQ_printf(m,
        "---------------------------------------------------------\n");
#define __P(F) \
    SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)F)
#define P(F) \
    SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)p->F)
#define __PN(F) \
    SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
#define PN(F) \
    SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))

    PN(se.exec_start);
    PN(se.vruntime);
    PN(se.sum_exec_runtime);

    nr_switches = p->nvcsw + p->nivcsw;

#ifdef CONFIG_SCHEDSTATS
    PN(se.statistics.wait_start);
    PN(se.statistics.sleep_start);
    PN(se.statistics.block_start);
    PN(se.statistics.sleep_max);
    PN(se.statistics.block_max);
    PN(se.statistics.exec_max);
    PN(se.statistics.slice_max);
    PN(se.statistics.wait_max);
    PN(se.statistics.wait_sum);
    P(se.statistics.wait_count);
    PN(se.statistics.iowait_sum);
    P(se.statistics.iowait_count);
    P(se.nr_migrations);
    P(se.statistics.nr_migrations_cold);
    P(se.statistics.nr_failed_migrations_affine);
    P(se.statistics.nr_failed_migrations_running);
    P(se.statistics.nr_failed_migrations_hot);
    P(se.statistics.nr_forced_migrations);
    P(se.statistics.nr_wakeups);
    P(se.statistics.nr_wakeups_sync);
    P(se.statistics.nr_wakeups_migrate);
    P(se.statistics.nr_wakeups_local);
    P(se.statistics.nr_wakeups_remote);
    P(se.statistics.nr_wakeups_affine);
    P(se.statistics.nr_wakeups_affine_attempts);
    P(se.statistics.nr_wakeups_passive);
    P(se.statistics.nr_wakeups_idle);

    {
        u64 avg_atom, avg_per_cpu;

        avg_atom = p->se.sum_exec_runtime;
        if (nr_switches)
            do_div(avg_atom, nr_switches);
        else
            avg_atom = -1LL;

        avg_per_cpu = p->se.sum_exec_runtime;
        if (p->se.nr_migrations) {
            avg_per_cpu = div64_u64(avg_per_cpu,
                        p->se.nr_migrations);
        } else {
            avg_per_cpu = -1LL;
        }

        __PN(avg_atom);
        __PN(avg_per_cpu);
    }
#endif
    __P(nr_switches);
    SEQ_printf(m, "%-35s:%21Ld\n",
           "nr_voluntary_switches", (long long)p->nvcsw);
    SEQ_printf(m, "%-35s:%21Ld\n",
           "nr_involuntary_switches", (long long)p->nivcsw);

    P(se.load.weight);
    P(policy);
    P(prio);
#undef PN
#undef __PN
#undef P
#undef __P

    {
        unsigned int this_cpu = raw_smp_processor_id();
        u64 t0, t1;

        t0 = cpu_clock(this_cpu);
        t1 = cpu_clock(this_cpu);
        SEQ_printf(m, "%-35s:%21Ld\n",
               "clock-delta", (long long)(t1-t0));
    }
}

void proc_sched_set_task(struct task_struct *p)
{
#ifdef CONFIG_SCHEDSTATS
    memset(&p->se.statistics, 0, sizeof(p->se.statistics));
#endif
}