builtin-sched.c

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#include "builtin.h"
#include "perf.h"

#include "util/util.h"
#include "util/evlist.h"
#include "util/cache.h"
#include "util/evsel.h"
#include "util/symbol.h"
#include "util/thread.h"
#include "util/header.h"
#include "util/session.h"
#include "util/tool.h"

#include "util/parse-options.h"
#include "util/trace-event.h"

#include "util/debug.h"

#include <sys/prctl.h>
#include <sys/resource.h>

#include <semaphore.h>
#include <pthread.h>
#include <math.h>

#define PR_SET_NAME     15               /* Set process name */
#define MAX_CPUS        4096
#define COMM_LEN        20
#define SYM_LEN         129
#define MAX_PID         65536

struct sched_atom;

struct task_desc {
    unsigned long       nr;
    unsigned long       pid;
    char            comm[COMM_LEN];

    unsigned long       nr_events;
    unsigned long       curr_event;
    struct sched_atom   **atoms;

    pthread_t       thread;
    sem_t           sleep_sem;

    sem_t           ready_for_work;
    sem_t           work_done_sem;

    u64         cpu_usage;
};

enum sched_event_type {
    SCHED_EVENT_RUN,
    SCHED_EVENT_SLEEP,
    SCHED_EVENT_WAKEUP,
    SCHED_EVENT_MIGRATION,
};

struct sched_atom {
    enum sched_event_type   type;
    int         specific_wait;
    u64         timestamp;
    u64         duration;
    unsigned long       nr;
    sem_t           *wait_sem;
    struct task_desc    *wakee;
};

#define TASK_STATE_TO_CHAR_STR "RSDTtZX"

enum thread_state {
    THREAD_SLEEPING = 0,
    THREAD_WAIT_CPU,
    THREAD_SCHED_IN,
    THREAD_IGNORE
};

struct work_atom {
    struct list_head    list;
    enum thread_state   state;
    u64         sched_out_time;
    u64         wake_up_time;
    u64         sched_in_time;
    u64         runtime;
};

struct work_atoms {
    struct list_head    work_list;
    struct thread       *thread;
    struct rb_node      node;
    u64         max_lat;
    u64         max_lat_at;
    u64         total_lat;
    u64         nb_atoms;
    u64         total_runtime;
};

typedef int (*sort_fn_t)(struct work_atoms *, struct work_atoms *);

struct perf_sched;

struct trace_sched_handler {
    int (*switch_event)(struct perf_sched *sched, struct perf_evsel *evsel,
                struct perf_sample *sample, struct machine *machine);

    int (*runtime_event)(struct perf_sched *sched, struct perf_evsel *evsel,
                 struct perf_sample *sample, struct machine *machine);

    int (*wakeup_event)(struct perf_sched *sched, struct perf_evsel *evsel,
                struct perf_sample *sample, struct machine *machine);

    int (*fork_event)(struct perf_sched *sched, struct perf_evsel *evsel,
              struct perf_sample *sample);

    int (*migrate_task_event)(struct perf_sched *sched,
                  struct perf_evsel *evsel,
                  struct perf_sample *sample,
                  struct machine *machine);
};

struct perf_sched {
    struct perf_tool tool;
    const char   *input_name;
    const char   *sort_order;
    unsigned long    nr_tasks;
    struct task_desc *pid_to_task[MAX_PID];
    struct task_desc **tasks;
    const struct trace_sched_handler *tp_handler;
    pthread_mutex_t  start_work_mutex;
    pthread_mutex_t  work_done_wait_mutex;
    int      profile_cpu;
/*
 * Track the current task - that way we can know whether there's any
 * weird events, such as a task being switched away that is not current.
 */
    int      max_cpu;
    u32      curr_pid[MAX_CPUS];
    struct thread    *curr_thread[MAX_CPUS];
    char         next_shortname1;
    char         next_shortname2;
    unsigned int     replay_repeat;
    unsigned long    nr_run_events;
    unsigned long    nr_sleep_events;
    unsigned long    nr_wakeup_events;
    unsigned long    nr_sleep_corrections;
    unsigned long    nr_run_events_optimized;
    unsigned long    targetless_wakeups;
    unsigned long    multitarget_wakeups;
    unsigned long    nr_runs;
    unsigned long    nr_timestamps;
    unsigned long    nr_unordered_timestamps;
    unsigned long    nr_state_machine_bugs;
    unsigned long    nr_context_switch_bugs;
    unsigned long    nr_events;
    unsigned long    nr_lost_chunks;
    unsigned long    nr_lost_events;
    u64      run_measurement_overhead;
    u64      sleep_measurement_overhead;
    u64      start_time;
    u64      cpu_usage;
    u64      runavg_cpu_usage;
    u64      parent_cpu_usage;
    u64      runavg_parent_cpu_usage;
    u64      sum_runtime;
    u64      sum_fluct;
    u64      run_avg;
    u64      all_runtime;
    u64      all_count;
    u64      cpu_last_switched[MAX_CPUS];
    struct rb_root   atom_root, sorted_atom_root;
    struct list_head sort_list, cmp_pid;
};

static u64 get_nsecs(void)
{
    struct timespec ts;

    clock_gettime(CLOCK_MONOTONIC, &ts);

    return ts.tv_sec * 1000000000ULL + ts.tv_nsec;
}

static void burn_nsecs(struct perf_sched *sched, u64 nsecs)
{
    u64 T0 = get_nsecs(), T1;

    do {
        T1 = get_nsecs();
    } while (T1 + sched->run_measurement_overhead < T0 + nsecs);
}

static void sleep_nsecs(u64 nsecs)
{
    struct timespec ts;

    ts.tv_nsec = nsecs % 999999999;
    ts.tv_sec = nsecs / 999999999;

    nanosleep(&ts, NULL);
}

static void calibrate_run_measurement_overhead(struct perf_sched *sched)
{
    u64 T0, T1, delta, min_delta = 1000000000ULL;
    int i;

    for (i = 0; i < 10; i++) {
        T0 = get_nsecs();
        burn_nsecs(sched, 0);
        T1 = get_nsecs();
        delta = T1-T0;
        min_delta = min(min_delta, delta);
    }
    sched->run_measurement_overhead = min_delta;

    printf("run measurement overhead: %" PRIu64 " nsecs\n", min_delta);
}

static void calibrate_sleep_measurement_overhead(struct perf_sched *sched)
{
    u64 T0, T1, delta, min_delta = 1000000000ULL;
    int i;

    for (i = 0; i < 10; i++) {
        T0 = get_nsecs();
        sleep_nsecs(10000);
        T1 = get_nsecs();
        delta = T1-T0;
        min_delta = min(min_delta, delta);
    }
    min_delta -= 10000;
    sched->sleep_measurement_overhead = min_delta;

    printf("sleep measurement overhead: %" PRIu64 " nsecs\n", min_delta);
}

static struct sched_atom *
get_new_event(struct task_desc *task, u64 timestamp)
{
    struct sched_atom *event = zalloc(sizeof(*event));
    unsigned long idx = task->nr_events;
    size_t size;

    event->timestamp = timestamp;
    event->nr = idx;

    task->nr_events++;
    size = sizeof(struct sched_atom *) * task->nr_events;
    task->atoms = realloc(task->atoms, size);
    BUG_ON(!task->atoms);

    task->atoms[idx] = event;

    return event;
}

static struct sched_atom *last_event(struct task_desc *task)
{
    if (!task->nr_events)
        return NULL;

    return task->atoms[task->nr_events - 1];
}

static void add_sched_event_run(struct perf_sched *sched, struct task_desc *task,
                u64 timestamp, u64 duration)
{
    struct sched_atom *event, *curr_event = last_event(task);

    /*
     * optimize an existing RUN event by merging this one
     * to it:
     */
    if (curr_event && curr_event->type == SCHED_EVENT_RUN) {
        sched->nr_run_events_optimized++;
        curr_event->duration += duration;
        return;
    }

    event = get_new_event(task, timestamp);

    event->type = SCHED_EVENT_RUN;
    event->duration = duration;

    sched->nr_run_events++;
}

static void add_sched_event_wakeup(struct perf_sched *sched, struct task_desc *task,
                   u64 timestamp, struct task_desc *wakee)
{
    struct sched_atom *event, *wakee_event;

    event = get_new_event(task, timestamp);
    event->type = SCHED_EVENT_WAKEUP;
    event->wakee = wakee;

    wakee_event = last_event(wakee);
    if (!wakee_event || wakee_event->type != SCHED_EVENT_SLEEP) {
        sched->targetless_wakeups++;
        return;
    }
    if (wakee_event->wait_sem) {
        sched->multitarget_wakeups++;
        return;
    }

    wakee_event->wait_sem = zalloc(sizeof(*wakee_event->wait_sem));
    sem_init(wakee_event->wait_sem, 0, 0);
    wakee_event->specific_wait = 1;
    event->wait_sem = wakee_event->wait_sem;

    sched->nr_wakeup_events++;
}

static void add_sched_event_sleep(struct perf_sched *sched, struct task_desc *task,
                  u64 timestamp, u64 task_state __maybe_unused)
{
    struct sched_atom *event = get_new_event(task, timestamp);

    event->type = SCHED_EVENT_SLEEP;

    sched->nr_sleep_events++;
}

static struct task_desc *register_pid(struct perf_sched *sched,
                      unsigned long pid, const char *comm)
{
    struct task_desc *task;

    BUG_ON(pid >= MAX_PID);

    task = sched->pid_to_task[pid];

    if (task)
        return task;

    task = zalloc(sizeof(*task));
    task->pid = pid;
    task->nr = sched->nr_tasks;
    strcpy(task->comm, comm);
    /*
     * every task starts in sleeping state - this gets ignored
     * if there's no wakeup pointing to this sleep state:
     */
    add_sched_event_sleep(sched, task, 0, 0);

    sched->pid_to_task[pid] = task;
    sched->nr_tasks++;
    sched->tasks = realloc(sched->tasks, sched->nr_tasks * sizeof(struct task_task *));
    BUG_ON(!sched->tasks);
    sched->tasks[task->nr] = task;

    if (verbose)
        printf("registered task #%ld, PID %ld (%s)\n", sched->nr_tasks, pid, comm);

    return task;
}


static void print_task_traces(struct perf_sched *sched)
{
    struct task_desc *task;
    unsigned long i;

    for (i = 0; i < sched->nr_tasks; i++) {
        task = sched->tasks[i];
        printf("task %6ld (%20s:%10ld), nr_events: %ld\n",
            task->nr, task->comm, task->pid, task->nr_events);
    }
}

static void add_cross_task_wakeups(struct perf_sched *sched)
{
    struct task_desc *task1, *task2;
    unsigned long i, j;

    for (i = 0; i < sched->nr_tasks; i++) {
        task1 = sched->tasks[i];
        j = i + 1;
        if (j == sched->nr_tasks)
            j = 0;
        task2 = sched->tasks[j];
        add_sched_event_wakeup(sched, task1, 0, task2);
    }
}

static void perf_sched__process_event(struct perf_sched *sched,
                      struct sched_atom *atom)
{
    int ret = 0;

    switch (atom->type) {
        case SCHED_EVENT_RUN:
            burn_nsecs(sched, atom->duration);
            break;
        case SCHED_EVENT_SLEEP:
            if (atom->wait_sem)
                ret = sem_wait(atom->wait_sem);
            BUG_ON(ret);
            break;
        case SCHED_EVENT_WAKEUP:
            if (atom->wait_sem)
                ret = sem_post(atom->wait_sem);
            BUG_ON(ret);
            break;
        case SCHED_EVENT_MIGRATION:
            break;
        default:
            BUG_ON(1);
    }
}

static u64 get_cpu_usage_nsec_parent(void)
{
    struct rusage ru;
    u64 sum;
    int err;

    err = getrusage(RUSAGE_SELF, &ru);
    BUG_ON(err);

    sum =  ru.ru_utime.tv_sec*1e9 + ru.ru_utime.tv_usec*1e3;
    sum += ru.ru_stime.tv_sec*1e9 + ru.ru_stime.tv_usec*1e3;

    return sum;
}

static int self_open_counters(void)
{
    struct perf_event_attr attr;
    int fd;

    memset(&attr, 0, sizeof(attr));

    attr.type = PERF_TYPE_SOFTWARE;
    attr.config = PERF_COUNT_SW_TASK_CLOCK;

    fd = sys_perf_event_open(&attr, 0, -1, -1, 0);

    if (fd < 0)
        pr_err("Error: sys_perf_event_open() syscall returned "
               "with %d (%s)\n", fd, strerror(errno));
    return fd;
}

static u64 get_cpu_usage_nsec_self(int fd)
{
    u64 runtime;
    int ret;

    ret = read(fd, &runtime, sizeof(runtime));
    BUG_ON(ret != sizeof(runtime));

    return runtime;
}

struct sched_thread_parms {
    struct task_desc  *task;
    struct perf_sched *sched;
};

static void *thread_func(void *ctx)
{
    struct sched_thread_parms *parms = ctx;
    struct task_desc *this_task = parms->task;
    struct perf_sched *sched = parms->sched;
    u64 cpu_usage_0, cpu_usage_1;
    unsigned long i, ret;
    char comm2[22];
    int fd;

    free(parms);

    sprintf(comm2, ":%s", this_task->comm);
    prctl(PR_SET_NAME, comm2);
    fd = self_open_counters();
    if (fd < 0)
        return NULL;
again:
    ret = sem_post(&this_task->ready_for_work);
    BUG_ON(ret);
    ret = pthread_mutex_lock(&sched->start_work_mutex);
    BUG_ON(ret);
    ret = pthread_mutex_unlock(&sched->start_work_mutex);
    BUG_ON(ret);

    cpu_usage_0 = get_cpu_usage_nsec_self(fd);

    for (i = 0; i < this_task->nr_events; i++) {
        this_task->curr_event = i;
        perf_sched__process_event(sched, this_task->atoms[i]);
    }

    cpu_usage_1 = get_cpu_usage_nsec_self(fd);
    this_task->cpu_usage = cpu_usage_1 - cpu_usage_0;
    ret = sem_post(&this_task->work_done_sem);
    BUG_ON(ret);

    ret = pthread_mutex_lock(&sched->work_done_wait_mutex);
    BUG_ON(ret);
    ret = pthread_mutex_unlock(&sched->work_done_wait_mutex);
    BUG_ON(ret);

    goto again;
}

static void create_tasks(struct perf_sched *sched)
{
    struct task_desc *task;
    pthread_attr_t attr;
    unsigned long i;
    int err;

    err = pthread_attr_init(&attr);
    BUG_ON(err);
    err = pthread_attr_setstacksize(&attr,
            (size_t) max(16 * 1024, PTHREAD_STACK_MIN));
    BUG_ON(err);
    err = pthread_mutex_lock(&sched->start_work_mutex);
    BUG_ON(err);
    err = pthread_mutex_lock(&sched->work_done_wait_mutex);
    BUG_ON(err);
    for (i = 0; i < sched->nr_tasks; i++) {
        struct sched_thread_parms *parms = malloc(sizeof(*parms));
        BUG_ON(parms == NULL);
        parms->task = task = sched->tasks[i];
        parms->sched = sched;
        sem_init(&task->sleep_sem, 0, 0);
        sem_init(&task->ready_for_work, 0, 0);
        sem_init(&task->work_done_sem, 0, 0);
        task->curr_event = 0;
        err = pthread_create(&task->thread, &attr, thread_func, parms);
        BUG_ON(err);
    }
}

static void wait_for_tasks(struct perf_sched *sched)
{
    u64 cpu_usage_0, cpu_usage_1;
    struct task_desc *task;
    unsigned long i, ret;

    sched->start_time = get_nsecs();
    sched->cpu_usage = 0;
    pthread_mutex_unlock(&sched->work_done_wait_mutex);

    for (i = 0; i < sched->nr_tasks; i++) {
        task = sched->tasks[i];
        ret = sem_wait(&task->ready_for_work);
        BUG_ON(ret);
        sem_init(&task->ready_for_work, 0, 0);
    }
    ret = pthread_mutex_lock(&sched->work_done_wait_mutex);
    BUG_ON(ret);

    cpu_usage_0 = get_cpu_usage_nsec_parent();

    pthread_mutex_unlock(&sched->start_work_mutex);

    for (i = 0; i < sched->nr_tasks; i++) {
        task = sched->tasks[i];
        ret = sem_wait(&task->work_done_sem);
        BUG_ON(ret);
        sem_init(&task->work_done_sem, 0, 0);
        sched->cpu_usage += task->cpu_usage;
        task->cpu_usage = 0;
    }

    cpu_usage_1 = get_cpu_usage_nsec_parent();
    if (!sched->runavg_cpu_usage)
        sched->runavg_cpu_usage = sched->cpu_usage;
    sched->runavg_cpu_usage = (sched->runavg_cpu_usage * 9 + sched->cpu_usage) / 10;

    sched->parent_cpu_usage = cpu_usage_1 - cpu_usage_0;
    if (!sched->runavg_parent_cpu_usage)
        sched->runavg_parent_cpu_usage = sched->parent_cpu_usage;
    sched->runavg_parent_cpu_usage = (sched->runavg_parent_cpu_usage * 9 +
                     sched->parent_cpu_usage)/10;

    ret = pthread_mutex_lock(&sched->start_work_mutex);
    BUG_ON(ret);

    for (i = 0; i < sched->nr_tasks; i++) {
        task = sched->tasks[i];
        sem_init(&task->sleep_sem, 0, 0);
        task->curr_event = 0;
    }
}

static void run_one_test(struct perf_sched *sched)
{
    u64 T0, T1, delta, avg_delta, fluct;

    T0 = get_nsecs();
    wait_for_tasks(sched);
    T1 = get_nsecs();

    delta = T1 - T0;
    sched->sum_runtime += delta;
    sched->nr_runs++;

    avg_delta = sched->sum_runtime / sched->nr_runs;
    if (delta < avg_delta)
        fluct = avg_delta - delta;
    else
        fluct = delta - avg_delta;
    sched->sum_fluct += fluct;
    if (!sched->run_avg)
        sched->run_avg = delta;
    sched->run_avg = (sched->run_avg * 9 + delta) / 10;

    printf("#%-3ld: %0.3f, ", sched->nr_runs, (double)delta / 1000000.0);

    printf("ravg: %0.2f, ", (double)sched->run_avg / 1e6);

    printf("cpu: %0.2f / %0.2f",
        (double)sched->cpu_usage / 1e6, (double)sched->runavg_cpu_usage / 1e6);

#if 0
    /*
     * rusage statistics done by the parent, these are less
     * accurate than the sched->sum_exec_runtime based statistics:
     */
    printf(" [%0.2f / %0.2f]",
        (double)sched->parent_cpu_usage/1e6,
        (double)sched->runavg_parent_cpu_usage/1e6);
#endif

    printf("\n");

    if (sched->nr_sleep_corrections)
        printf(" (%ld sleep corrections)\n", sched->nr_sleep_corrections);
    sched->nr_sleep_corrections = 0;
}

static void test_calibrations(struct perf_sched *sched)
{
    u64 T0, T1;

    T0 = get_nsecs();
    burn_nsecs(sched, 1e6);
    T1 = get_nsecs();

    printf("the run test took %" PRIu64 " nsecs\n", T1 - T0);

    T0 = get_nsecs();
    sleep_nsecs(1e6);
    T1 = get_nsecs();

    printf("the sleep test took %" PRIu64 " nsecs\n", T1 - T0);
}

static int
replay_wakeup_event(struct perf_sched *sched,
            struct perf_evsel *evsel, struct perf_sample *sample,
            struct machine *machine __maybe_unused)
{
    const char *comm = perf_evsel__strval(evsel, sample, "comm");
    const u32 pid    = perf_evsel__intval(evsel, sample, "pid");
    struct task_desc *waker, *wakee;

    if (verbose) {
        printf("sched_wakeup event %p\n", evsel);

        printf(" ... pid %d woke up %s/%d\n", sample->tid, comm, pid);
    }

    waker = register_pid(sched, sample->tid, "<unknown>");
    wakee = register_pid(sched, pid, comm);

    add_sched_event_wakeup(sched, waker, sample->time, wakee);
    return 0;
}

static int replay_switch_event(struct perf_sched *sched,
                   struct perf_evsel *evsel,
                   struct perf_sample *sample,
                   struct machine *machine __maybe_unused)
{
    const char *prev_comm  = perf_evsel__strval(evsel, sample, "prev_comm"),
           *next_comm  = perf_evsel__strval(evsel, sample, "next_comm");
    const u32 prev_pid = perf_evsel__intval(evsel, sample, "prev_pid"),
          next_pid = perf_evsel__intval(evsel, sample, "next_pid");
    const u64 prev_state = perf_evsel__intval(evsel, sample, "prev_state");
    struct task_desc *prev, __maybe_unused *next;
    u64 timestamp0, timestamp = sample->time;
    int cpu = sample->cpu;
    s64 delta;

    if (verbose)
        printf("sched_switch event %p\n", evsel);

    if (cpu >= MAX_CPUS || cpu < 0)
        return 0;

    timestamp0 = sched->cpu_last_switched[cpu];
    if (timestamp0)
        delta = timestamp - timestamp0;
    else
        delta = 0;

    if (delta < 0) {
        pr_err("hm, delta: %" PRIu64 " < 0 ?\n", delta);
        return -1;
    }

    pr_debug(" ... switch from %s/%d to %s/%d [ran %" PRIu64 " nsecs]\n",
         prev_comm, prev_pid, next_comm, next_pid, delta);

    prev = register_pid(sched, prev_pid, prev_comm);
    next = register_pid(sched, next_pid, next_comm);

    sched->cpu_last_switched[cpu] = timestamp;

    add_sched_event_run(sched, prev, timestamp, delta);
    add_sched_event_sleep(sched, prev, timestamp, prev_state);

    return 0;
}

static int replay_fork_event(struct perf_sched *sched, struct perf_evsel *evsel,
                 struct perf_sample *sample)
{
    const char *parent_comm = perf_evsel__strval(evsel, sample, "parent_comm"),
           *child_comm  = perf_evsel__strval(evsel, sample, "child_comm");
    const u32 parent_pid  = perf_evsel__intval(evsel, sample, "parent_pid"),
          child_pid  = perf_evsel__intval(evsel, sample, "child_pid");

    if (verbose) {
        printf("sched_fork event %p\n", evsel);
        printf("... parent: %s/%d\n", parent_comm, parent_pid);
        printf("...  child: %s/%d\n", child_comm, child_pid);
    }

    register_pid(sched, parent_pid, parent_comm);
    register_pid(sched, child_pid, child_comm);
    return 0;
}

struct sort_dimension {
    const char      *name;
    sort_fn_t       cmp;
    struct list_head    list;
};

static int
thread_lat_cmp(struct list_head *list, struct work_atoms *l, struct work_atoms *r)
{
    struct sort_dimension *sort;
    int ret = 0;

    BUG_ON(list_empty(list));

    list_for_each_entry(sort, list, list) {
        ret = sort->cmp(l, r);
        if (ret)
            return ret;
    }

    return ret;
}

static struct work_atoms *
thread_atoms_search(struct rb_root *root, struct thread *thread,
             struct list_head *sort_list)
{
    struct rb_node *node = root->rb_node;
    struct work_atoms key = { .thread = thread };

    while (node) {
        struct work_atoms *atoms;
        int cmp;

        atoms = container_of(node, struct work_atoms, node);

        cmp = thread_lat_cmp(sort_list, &key, atoms);
        if (cmp > 0)
            node = node->rb_left;
        else if (cmp < 0)
            node = node->rb_right;
        else {
            BUG_ON(thread != atoms->thread);
            return atoms;
        }
    }
    return NULL;
}

static void
__thread_latency_insert(struct rb_root *root, struct work_atoms *data,
             struct list_head *sort_list)
{
    struct rb_node **new = &(root->rb_node), *parent = NULL;

    while (*new) {
        struct work_atoms *this;
        int cmp;

        this = container_of(*new, struct work_atoms, node);
        parent = *new;

        cmp = thread_lat_cmp(sort_list, data, this);

        if (cmp > 0)
            new = &((*new)->rb_left);
        else
            new = &((*new)->rb_right);
    }

    rb_link_node(&data->node, parent, new);
    rb_insert_color(&data->node, root);
}

static int thread_atoms_insert(struct perf_sched *sched, struct thread *thread)
{
    struct work_atoms *atoms = zalloc(sizeof(*atoms));
    if (!atoms) {
        pr_err("No memory at %s\n", __func__);
        return -1;
    }

    atoms->thread = thread;
    INIT_LIST_HEAD(&atoms->work_list);
    __thread_latency_insert(&sched->atom_root, atoms, &sched->cmp_pid);
    return 0;
}

static int latency_fork_event(struct perf_sched *sched __maybe_unused,
                  struct perf_evsel *evsel __maybe_unused,
                  struct perf_sample *sample __maybe_unused)
{
    /* should insert the newcomer */
    return 0;
}

static char sched_out_state(u64 prev_state)
{
    const char *str = TASK_STATE_TO_CHAR_STR;

    return str[prev_state];
}

static int
add_sched_out_event(struct work_atoms *atoms,
            char run_state,
            u64 timestamp)
{
    struct work_atom *atom = zalloc(sizeof(*atom));
    if (!atom) {
        pr_err("Non memory at %s", __func__);
        return -1;
    }

    atom->sched_out_time = timestamp;

    if (run_state == 'R') {
        atom->state = THREAD_WAIT_CPU;
        atom->wake_up_time = atom->sched_out_time;
    }

    list_add_tail(&atom->list, &atoms->work_list);
    return 0;
}

static void
add_runtime_event(struct work_atoms *atoms, u64 delta,
          u64 timestamp __maybe_unused)
{
    struct work_atom *atom;

    BUG_ON(list_empty(&atoms->work_list));

    atom = list_entry(atoms->work_list.prev, struct work_atom, list);

    atom->runtime += delta;
    atoms->total_runtime += delta;
}

static void
add_sched_in_event(struct work_atoms *atoms, u64 timestamp)
{
    struct work_atom *atom;
    u64 delta;

    if (list_empty(&atoms->work_list))
        return;

    atom = list_entry(atoms->work_list.prev, struct work_atom, list);

    if (atom->state != THREAD_WAIT_CPU)
        return;

    if (timestamp < atom->wake_up_time) {
        atom->state = THREAD_IGNORE;
        return;
    }

    atom->state = THREAD_SCHED_IN;
    atom->sched_in_time = timestamp;

    delta = atom->sched_in_time - atom->wake_up_time;
    atoms->total_lat += delta;
    if (delta > atoms->max_lat) {
        atoms->max_lat = delta;
        atoms->max_lat_at = timestamp;
    }
    atoms->nb_atoms++;
}

static int latency_switch_event(struct perf_sched *sched,
                struct perf_evsel *evsel,
                struct perf_sample *sample,
                struct machine *machine)
{
    const u32 prev_pid = perf_evsel__intval(evsel, sample, "prev_pid"),
          next_pid = perf_evsel__intval(evsel, sample, "next_pid");
    const u64 prev_state = perf_evsel__intval(evsel, sample, "prev_state");
    struct work_atoms *out_events, *in_events;
    struct thread *sched_out, *sched_in;
    u64 timestamp0, timestamp = sample->time;
    int cpu = sample->cpu;
    s64 delta;

    BUG_ON(cpu >= MAX_CPUS || cpu < 0);

    timestamp0 = sched->cpu_last_switched[cpu];
    sched->cpu_last_switched[cpu] = timestamp;
    if (timestamp0)
        delta = timestamp - timestamp0;
    else
        delta = 0;

    if (delta < 0) {
        pr_err("hm, delta: %" PRIu64 " < 0 ?\n", delta);
        return -1;
    }

    sched_out = machine__findnew_thread(machine, prev_pid);
    sched_in = machine__findnew_thread(machine, next_pid);

    out_events = thread_atoms_search(&sched->atom_root, sched_out, &sched->cmp_pid);
    if (!out_events) {
        if (thread_atoms_insert(sched, sched_out))
            return -1;
        out_events = thread_atoms_search(&sched->atom_root, sched_out, &sched->cmp_pid);
        if (!out_events) {
            pr_err("out-event: Internal tree error");
            return -1;
        }
    }
    if (add_sched_out_event(out_events, sched_out_state(prev_state), timestamp))
        return -1;

    in_events = thread_atoms_search(&sched->atom_root, sched_in, &sched->cmp_pid);
    if (!in_events) {
        if (thread_atoms_insert(sched, sched_in))
            return -1;
        in_events = thread_atoms_search(&sched->atom_root, sched_in, &sched->cmp_pid);
        if (!in_events) {
            pr_err("in-event: Internal tree error");
            return -1;
        }
        /*
         * Take came in we have not heard about yet,
         * add in an initial atom in runnable state:
         */
        if (add_sched_out_event(in_events, 'R', timestamp))
            return -1;
    }
    add_sched_in_event(in_events, timestamp);

    return 0;
}

static int latency_runtime_event(struct perf_sched *sched,
                 struct perf_evsel *evsel,
                 struct perf_sample *sample,
                 struct machine *machine)
{
    const u32 pid      = perf_evsel__intval(evsel, sample, "pid");
    const u64 runtime  = perf_evsel__intval(evsel, sample, "runtime");
    struct thread *thread = machine__findnew_thread(machine, pid);
    struct work_atoms *atoms = thread_atoms_search(&sched->atom_root, thread, &sched->cmp_pid);
    u64 timestamp = sample->time;
    int cpu = sample->cpu;

    BUG_ON(cpu >= MAX_CPUS || cpu < 0);
    if (!atoms) {
        if (thread_atoms_insert(sched, thread))
            return -1;
        atoms = thread_atoms_search(&sched->atom_root, thread, &sched->cmp_pid);
        if (!atoms) {
            pr_err("in-event: Internal tree error");
            return -1;
        }
        if (add_sched_out_event(atoms, 'R', timestamp))
            return -1;
    }

    add_runtime_event(atoms, runtime, timestamp);
    return 0;
}

static int latency_wakeup_event(struct perf_sched *sched,
                struct perf_evsel *evsel,
                struct perf_sample *sample,
                struct machine *machine)
{
    const u32 pid     = perf_evsel__intval(evsel, sample, "pid"),
          success = perf_evsel__intval(evsel, sample, "success");
    struct work_atoms *atoms;
    struct work_atom *atom;
    struct thread *wakee;
    u64 timestamp = sample->time;

    /* Note for later, it may be interesting to observe the failing cases */
    if (!success)
        return 0;

    wakee = machine__findnew_thread(machine, pid);
    atoms = thread_atoms_search(&sched->atom_root, wakee, &sched->cmp_pid);
    if (!atoms) {
        if (thread_atoms_insert(sched, wakee))
            return -1;
        atoms = thread_atoms_search(&sched->atom_root, wakee, &sched->cmp_pid);
        if (!atoms) {
            pr_err("wakeup-event: Internal tree error");
            return -1;
        }
        if (add_sched_out_event(atoms, 'S', timestamp))
            return -1;
    }

    BUG_ON(list_empty(&atoms->work_list));

    atom = list_entry(atoms->work_list.prev, struct work_atom, list);

    /*
     * You WILL be missing events if you've recorded only
     * one CPU, or are only looking at only one, so don't
     * make useless noise.
     */
    if (sched->profile_cpu == -1 && atom->state != THREAD_SLEEPING)
        sched->nr_state_machine_bugs++;

    sched->nr_timestamps++;
    if (atom->sched_out_time > timestamp) {
        sched->nr_unordered_timestamps++;
        return 0;
    }

    atom->state = THREAD_WAIT_CPU;
    atom->wake_up_time = timestamp;
    return 0;
}

static int latency_migrate_task_event(struct perf_sched *sched,
                      struct perf_evsel *evsel,
                      struct perf_sample *sample,
                      struct machine *machine)
{
    const u32 pid = perf_evsel__intval(evsel, sample, "pid");
    u64 timestamp = sample->time;
    struct work_atoms *atoms;
    struct work_atom *atom;
    struct thread *migrant;

    /*
     * Only need to worry about migration when profiling one CPU.
     */
    if (sched->profile_cpu == -1)
        return 0;

    migrant = machine__findnew_thread(machine, pid);
    atoms = thread_atoms_search(&sched->atom_root, migrant, &sched->cmp_pid);
    if (!atoms) {
        if (thread_atoms_insert(sched, migrant))
            return -1;
        register_pid(sched, migrant->pid, migrant->comm);
        atoms = thread_atoms_search(&sched->atom_root, migrant, &sched->cmp_pid);
        if (!atoms) {
            pr_err("migration-event: Internal tree error");
            return -1;
        }
        if (add_sched_out_event(atoms, 'R', timestamp))
            return -1;
    }

    BUG_ON(list_empty(&atoms->work_list));

    atom = list_entry(atoms->work_list.prev, struct work_atom, list);
    atom->sched_in_time = atom->sched_out_time = atom->wake_up_time = timestamp;

    sched->nr_timestamps++;

    if (atom->sched_out_time > timestamp)
        sched->nr_unordered_timestamps++;

    return 0;
}

static void output_lat_thread(struct perf_sched *sched, struct work_atoms *work_list)
{
    int i;
    int ret;
    u64 avg;

    if (!work_list->nb_atoms)
        return;
    /*
     * Ignore idle threads:
     */
    if (!strcmp(work_list->thread->comm, "swapper"))
        return;

    sched->all_runtime += work_list->total_runtime;
    sched->all_count   += work_list->nb_atoms;

    ret = printf("  %s:%d ", work_list->thread->comm, work_list->thread->pid);

    for (i = 0; i < 24 - ret; i++)
        printf(" ");

    avg = work_list->total_lat / work_list->nb_atoms;

    printf("|%11.3f ms |%9" PRIu64 " | avg:%9.3f ms | max:%9.3f ms | max at: %9.6f s\n",
          (double)work_list->total_runtime / 1e6,
         work_list->nb_atoms, (double)avg / 1e6,
         (double)work_list->max_lat / 1e6,
         (double)work_list->max_lat_at / 1e9);
}

static int pid_cmp(struct work_atoms *l, struct work_atoms *r)
{
    if (l->thread->pid < r->thread->pid)
        return -1;
    if (l->thread->pid > r->thread->pid)
        return 1;

    return 0;
}

static int avg_cmp(struct work_atoms *l, struct work_atoms *r)
{
    u64 avgl, avgr;

    if (!l->nb_atoms)
        return -1;

    if (!r->nb_atoms)
        return 1;

    avgl = l->total_lat / l->nb_atoms;
    avgr = r->total_lat / r->nb_atoms;

    if (avgl < avgr)
        return -1;
    if (avgl > avgr)
        return 1;

    return 0;
}

static int max_cmp(struct work_atoms *l, struct work_atoms *r)
{
    if (l->max_lat < r->max_lat)
        return -1;
    if (l->max_lat > r->max_lat)
        return 1;

    return 0;
}

static int switch_cmp(struct work_atoms *l, struct work_atoms *r)
{
    if (l->nb_atoms < r->nb_atoms)
        return -1;
    if (l->nb_atoms > r->nb_atoms)
        return 1;

    return 0;
}

static int runtime_cmp(struct work_atoms *l, struct work_atoms *r)
{
    if (l->total_runtime < r->total_runtime)
        return -1;
    if (l->total_runtime > r->total_runtime)
        return 1;

    return 0;
}

static int sort_dimension__add(const char *tok, struct list_head *list)
{
    size_t i;
    static struct sort_dimension avg_sort_dimension = {
        .name = "avg",
        .cmp  = avg_cmp,
    };
    static struct sort_dimension max_sort_dimension = {
        .name = "max",
        .cmp  = max_cmp,
    };
    static struct sort_dimension pid_sort_dimension = {
        .name = "pid",
        .cmp  = pid_cmp,
    };
    static struct sort_dimension runtime_sort_dimension = {
        .name = "runtime",
        .cmp  = runtime_cmp,
    };
    static struct sort_dimension switch_sort_dimension = {
        .name = "switch",
        .cmp  = switch_cmp,
    };
    struct sort_dimension *available_sorts[] = {
        &pid_sort_dimension,
        &avg_sort_dimension,
        &max_sort_dimension,
        &switch_sort_dimension,
        &runtime_sort_dimension,
    };

    for (i = 0; i < ARRAY_SIZE(available_sorts); i++) {
        if (!strcmp(available_sorts[i]->name, tok)) {
            list_add_tail(&available_sorts[i]->list, list);

            return 0;
        }
    }

    return -1;
}

static void perf_sched__sort_lat(struct perf_sched *sched)
{
    struct rb_node *node;

    for (;;) {
        struct work_atoms *data;
        node = rb_first(&sched->atom_root);
        if (!node)
            break;

        rb_erase(node, &sched->atom_root);
        data = rb_entry(node, struct work_atoms, node);
        __thread_latency_insert(&sched->sorted_atom_root, data, &sched->sort_list);
    }
}

static int process_sched_wakeup_event(struct perf_tool *tool,
                      struct perf_evsel *evsel,
                      struct perf_sample *sample,
                      struct machine *machine)
{
    struct perf_sched *sched = container_of(tool, struct perf_sched, tool);

    if (sched->tp_handler->wakeup_event)
        return sched->tp_handler->wakeup_event(sched, evsel, sample, machine);

    return 0;
}

static int map_switch_event(struct perf_sched *sched, struct perf_evsel *evsel,
                struct perf_sample *sample, struct machine *machine)
{
    const u32 prev_pid = perf_evsel__intval(evsel, sample, "prev_pid"),
          next_pid = perf_evsel__intval(evsel, sample, "next_pid");
    struct thread *sched_out __maybe_unused, *sched_in;
    int new_shortname;
    u64 timestamp0, timestamp = sample->time;
    s64 delta;
    int cpu, this_cpu = sample->cpu;

    BUG_ON(this_cpu >= MAX_CPUS || this_cpu < 0);

    if (this_cpu > sched->max_cpu)
        sched->max_cpu = this_cpu;

    timestamp0 = sched->cpu_last_switched[this_cpu];
    sched->cpu_last_switched[this_cpu] = timestamp;
    if (timestamp0)
        delta = timestamp - timestamp0;
    else
        delta = 0;

    if (delta < 0) {
        pr_err("hm, delta: %" PRIu64 " < 0 ?\n", delta);
        return -1;
    }

    sched_out = machine__findnew_thread(machine, prev_pid);
    sched_in = machine__findnew_thread(machine, next_pid);

    sched->curr_thread[this_cpu] = sched_in;

    printf("  ");

    new_shortname = 0;
    if (!sched_in->shortname[0]) {
        sched_in->shortname[0] = sched->next_shortname1;
        sched_in->shortname[1] = sched->next_shortname2;

        if (sched->next_shortname1 < 'Z') {
            sched->next_shortname1++;
        } else {
            sched->next_shortname1='A';
            if (sched->next_shortname2 < '9') {
                sched->next_shortname2++;
            } else {
                sched->next_shortname2='0';
            }
        }
        new_shortname = 1;
    }

    for (cpu = 0; cpu <= sched->max_cpu; cpu++) {
        if (cpu != this_cpu)
            printf(" ");
        else
            printf("*");

        if (sched->curr_thread[cpu]) {
            if (sched->curr_thread[cpu]->pid)
                printf("%2s ", sched->curr_thread[cpu]->shortname);
            else
                printf(".  ");
        } else
            printf("   ");
    }

    printf("  %12.6f secs ", (double)timestamp/1e9);
    if (new_shortname) {
        printf("%s => %s:%d\n",
            sched_in->shortname, sched_in->comm, sched_in->pid);
    } else {
        printf("\n");
    }

    return 0;
}

static int process_sched_switch_event(struct perf_tool *tool,
                      struct perf_evsel *evsel,
                      struct perf_sample *sample,
                      struct machine *machine)
{
    struct perf_sched *sched = container_of(tool, struct perf_sched, tool);
    int this_cpu = sample->cpu, err = 0;
    u32 prev_pid = perf_evsel__intval(evsel, sample, "prev_pid"),
        next_pid = perf_evsel__intval(evsel, sample, "next_pid");

    if (sched->curr_pid[this_cpu] != (u32)-1) {
        /*
         * Are we trying to switch away a PID that is
         * not current?
         */
        if (sched->curr_pid[this_cpu] != prev_pid)
            sched->nr_context_switch_bugs++;
    }

    if (sched->tp_handler->switch_event)
        err = sched->tp_handler->switch_event(sched, evsel, sample, machine);

    sched->curr_pid[this_cpu] = next_pid;
    return err;
}

static int process_sched_runtime_event(struct perf_tool *tool,
                       struct perf_evsel *evsel,
                       struct perf_sample *sample,
                       struct machine *machine)
{
    struct perf_sched *sched = container_of(tool, struct perf_sched, tool);

    if (sched->tp_handler->runtime_event)
        return sched->tp_handler->runtime_event(sched, evsel, sample, machine);

    return 0;
}

static int process_sched_fork_event(struct perf_tool *tool,
                    struct perf_evsel *evsel,
                    struct perf_sample *sample,
                    struct machine *machine __maybe_unused)
{
    struct perf_sched *sched = container_of(tool, struct perf_sched, tool);

    if (sched->tp_handler->fork_event)
        return sched->tp_handler->fork_event(sched, evsel, sample);

    return 0;
}

static int process_sched_exit_event(struct perf_tool *tool __maybe_unused,
                    struct perf_evsel *evsel,
                    struct perf_sample *sample __maybe_unused,
                    struct machine *machine __maybe_unused)
{
    pr_debug("sched_exit event %p\n", evsel);
    return 0;
}

static int process_sched_migrate_task_event(struct perf_tool *tool,
                        struct perf_evsel *evsel,
                        struct perf_sample *sample,
                        struct machine *machine)
{
    struct perf_sched *sched = container_of(tool, struct perf_sched, tool);

    if (sched->tp_handler->migrate_task_event)
        return sched->tp_handler->migrate_task_event(sched, evsel, sample, machine);

    return 0;
}

typedef int (*tracepoint_handler)(struct perf_tool *tool,
                  struct perf_evsel *evsel,
                  struct perf_sample *sample,
                  struct machine *machine);

static int perf_sched__process_tracepoint_sample(struct perf_tool *tool __maybe_unused,
                         union perf_event *event __maybe_unused,
                         struct perf_sample *sample,
                         struct perf_evsel *evsel,
                         struct machine *machine)
{
    struct thread *thread = machine__findnew_thread(machine, sample->tid);
    int err = 0;

    if (thread == NULL) {
        pr_debug("problem processing %s event, skipping it.\n",
             perf_evsel__name(evsel));
        return -1;
    }

    evsel->hists.stats.total_period += sample->period;
    hists__inc_nr_events(&evsel->hists, PERF_RECORD_SAMPLE);

    if (evsel->handler.func != NULL) {
        tracepoint_handler f = evsel->handler.func;
        err = f(tool, evsel, sample, machine);
    }

    return err;
}

static int perf_sched__read_events(struct perf_sched *sched, bool destroy,
                   struct perf_session **psession)
{
    const struct perf_evsel_str_handler handlers[] = {
        { "sched:sched_switch",       process_sched_switch_event, },
        { "sched:sched_stat_runtime", process_sched_runtime_event, },
        { "sched:sched_wakeup",       process_sched_wakeup_event, },
        { "sched:sched_wakeup_new",   process_sched_wakeup_event, },
        { "sched:sched_process_fork", process_sched_fork_event, },
        { "sched:sched_process_exit", process_sched_exit_event, },
        { "sched:sched_migrate_task", process_sched_migrate_task_event, },
    };
    struct perf_session *session;

    session = perf_session__new(sched->input_name, O_RDONLY, 0, false, &sched->tool);
    if (session == NULL) {
        pr_debug("No Memory for session\n");
        return -1;
    }

    if (perf_session__set_tracepoints_handlers(session, handlers))
        goto out_delete;

    if (perf_session__has_traces(session, "record -R")) {
        int err = perf_session__process_events(session, &sched->tool);
        if (err) {
            pr_err("Failed to process events, error %d", err);
            goto out_delete;
        }

        sched->nr_events      = session->hists.stats.nr_events[0];
        sched->nr_lost_events = session->hists.stats.total_lost;
        sched->nr_lost_chunks = session->hists.stats.nr_events[PERF_RECORD_LOST];
    }

    if (destroy)
        perf_session__delete(session);

    if (psession)
        *psession = session;

    return 0;

out_delete:
    perf_session__delete(session);
    return -1;
}

static void print_bad_events(struct perf_sched *sched)
{
    if (sched->nr_unordered_timestamps && sched->nr_timestamps) {
        printf("  INFO: %.3f%% unordered timestamps (%ld out of %ld)\n",
            (double)sched->nr_unordered_timestamps/(double)sched->nr_timestamps*100.0,
            sched->nr_unordered_timestamps, sched->nr_timestamps);
    }
    if (sched->nr_lost_events && sched->nr_events) {
        printf("  INFO: %.3f%% lost events (%ld out of %ld, in %ld chunks)\n",
            (double)sched->nr_lost_events/(double)sched->nr_events * 100.0,
            sched->nr_lost_events, sched->nr_events, sched->nr_lost_chunks);
    }
    if (sched->nr_state_machine_bugs && sched->nr_timestamps) {
        printf("  INFO: %.3f%% state machine bugs (%ld out of %ld)",
            (double)sched->nr_state_machine_bugs/(double)sched->nr_timestamps*100.0,
            sched->nr_state_machine_bugs, sched->nr_timestamps);
        if (sched->nr_lost_events)
            printf(" (due to lost events?)");
        printf("\n");
    }
    if (sched->nr_context_switch_bugs && sched->nr_timestamps) {
        printf("  INFO: %.3f%% context switch bugs (%ld out of %ld)",
            (double)sched->nr_context_switch_bugs/(double)sched->nr_timestamps*100.0,
            sched->nr_context_switch_bugs, sched->nr_timestamps);
        if (sched->nr_lost_events)
            printf(" (due to lost events?)");
        printf("\n");
    }
}

static int perf_sched__lat(struct perf_sched *sched)
{
    struct rb_node *next;
    struct perf_session *session;

    setup_pager();
    if (perf_sched__read_events(sched, false, &session))
        return -1;
    perf_sched__sort_lat(sched);

    printf("\n ---------------------------------------------------------------------------------------------------------------\n");
    printf("  Task                  |   Runtime ms  | Switches | Average delay ms | Maximum delay ms | Maximum delay at     |\n");
    printf(" ---------------------------------------------------------------------------------------------------------------\n");

    next = rb_first(&sched->sorted_atom_root);

    while (next) {
        struct work_atoms *work_list;

        work_list = rb_entry(next, struct work_atoms, node);
        output_lat_thread(sched, work_list);
        next = rb_next(next);
    }

    printf(" -----------------------------------------------------------------------------------------\n");
    printf("  TOTAL:                |%11.3f ms |%9" PRIu64 " |\n",
        (double)sched->all_runtime / 1e6, sched->all_count);

    printf(" ---------------------------------------------------\n");

    print_bad_events(sched);
    printf("\n");

    perf_session__delete(session);
    return 0;
}

static int perf_sched__map(struct perf_sched *sched)
{
    sched->max_cpu = sysconf(_SC_NPROCESSORS_CONF);

    setup_pager();
    if (perf_sched__read_events(sched, true, NULL))
        return -1;
    print_bad_events(sched);
    return 0;
}

static int perf_sched__replay(struct perf_sched *sched)
{
    unsigned long i;

    calibrate_run_measurement_overhead(sched);
    calibrate_sleep_measurement_overhead(sched);

    test_calibrations(sched);

    if (perf_sched__read_events(sched, true, NULL))
        return -1;

    printf("nr_run_events:        %ld\n", sched->nr_run_events);
    printf("nr_sleep_events:      %ld\n", sched->nr_sleep_events);
    printf("nr_wakeup_events:     %ld\n", sched->nr_wakeup_events);

    if (sched->targetless_wakeups)
        printf("target-less wakeups:  %ld\n", sched->targetless_wakeups);
    if (sched->multitarget_wakeups)
        printf("multi-target wakeups: %ld\n", sched->multitarget_wakeups);
    if (sched->nr_run_events_optimized)
        printf("run atoms optimized: %ld\n",
            sched->nr_run_events_optimized);

    print_task_traces(sched);
    add_cross_task_wakeups(sched);

    create_tasks(sched);
    printf("------------------------------------------------------------\n");
    for (i = 0; i < sched->replay_repeat; i++)
        run_one_test(sched);

    return 0;
}

static void setup_sorting(struct perf_sched *sched, const struct option *options,
              const char * const usage_msg[])
{
    char *tmp, *tok, *str = strdup(sched->sort_order);

    for (tok = strtok_r(str, ", ", &tmp);
            tok; tok = strtok_r(NULL, ", ", &tmp)) {
        if (sort_dimension__add(tok, &sched->sort_list) < 0) {
            error("Unknown --sort key: `%s'", tok);
            usage_with_options(usage_msg, options);
        }
    }

    free(str);

    sort_dimension__add("pid", &sched->cmp_pid);
}

static int __cmd_record(int argc, const char **argv)
{
    unsigned int rec_argc, i, j;
    const char **rec_argv;
    const char * const record_args[] = {
        "record",
        "-a",
        "-R",
        "-f",
        "-m", "1024",
        "-c", "1",
        "-e", "sched:sched_switch",
        "-e", "sched:sched_stat_wait",
        "-e", "sched:sched_stat_sleep",
        "-e", "sched:sched_stat_iowait",
        "-e", "sched:sched_stat_runtime",
        "-e", "sched:sched_process_exit",
        "-e", "sched:sched_process_fork",
        "-e", "sched:sched_wakeup",
        "-e", "sched:sched_migrate_task",
    };

    rec_argc = ARRAY_SIZE(record_args) + argc - 1;
    rec_argv = calloc(rec_argc + 1, sizeof(char *));

    if (rec_argv == NULL)
        return -ENOMEM;

    for (i = 0; i < ARRAY_SIZE(record_args); i++)
        rec_argv[i] = strdup(record_args[i]);

    for (j = 1; j < (unsigned int)argc; j++, i++)
        rec_argv[i] = argv[j];

    BUG_ON(i != rec_argc);

    return cmd_record(i, rec_argv, NULL);
}

int cmd_sched(int argc, const char **argv, const char *prefix __maybe_unused)
{
    const char default_sort_order[] = "avg, max, switch, runtime";
    struct perf_sched sched = {
        .tool = {
            .sample      = perf_sched__process_tracepoint_sample,
            .comm        = perf_event__process_comm,
            .lost        = perf_event__process_lost,
            .fork        = perf_event__process_task,
            .ordered_samples = true,
        },
        .cmp_pid          = LIST_HEAD_INIT(sched.cmp_pid),
        .sort_list        = LIST_HEAD_INIT(sched.sort_list),
        .start_work_mutex     = PTHREAD_MUTEX_INITIALIZER,
        .work_done_wait_mutex = PTHREAD_MUTEX_INITIALIZER,
        .curr_pid         = { [0 ... MAX_CPUS - 1] = -1 },
        .sort_order       = default_sort_order,
        .replay_repeat        = 10,
        .profile_cpu          = -1,
        .next_shortname1      = 'A',
        .next_shortname2      = '0',
    };
    const struct option latency_options[] = {
    OPT_STRING('s', "sort", &sched.sort_order, "key[,key2...]",
           "sort by key(s): runtime, switch, avg, max"),
    OPT_INCR('v', "verbose", &verbose,
            "be more verbose (show symbol address, etc)"),
    OPT_INTEGER('C', "CPU", &sched.profile_cpu,
            "CPU to profile on"),
    OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
            "dump raw trace in ASCII"),
    OPT_END()
    };
    const struct option replay_options[] = {
    OPT_UINTEGER('r', "repeat", &sched.replay_repeat,
             "repeat the workload replay N times (-1: infinite)"),
    OPT_INCR('v', "verbose", &verbose,
            "be more verbose (show symbol address, etc)"),
    OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
            "dump raw trace in ASCII"),
    OPT_END()
    };
    const struct option sched_options[] = {
    OPT_STRING('i', "input", &sched.input_name, "file",
            "input file name"),
    OPT_INCR('v', "verbose", &verbose,
            "be more verbose (show symbol address, etc)"),
    OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
            "dump raw trace in ASCII"),
    OPT_END()
    };
    const char * const latency_usage[] = {
        "perf sched latency [<options>]",
        NULL
    };
    const char * const replay_usage[] = {
        "perf sched replay [<options>]",
        NULL
    };
    const char * const sched_usage[] = {
        "perf sched [<options>] {record|latency|map|replay|script}",
        NULL
    };
    struct trace_sched_handler lat_ops  = {
        .wakeup_event       = latency_wakeup_event,
        .switch_event       = latency_switch_event,
        .runtime_event      = latency_runtime_event,
        .fork_event     = latency_fork_event,
        .migrate_task_event = latency_migrate_task_event,
    };
    struct trace_sched_handler map_ops  = {
        .switch_event       = map_switch_event,
    };
    struct trace_sched_handler replay_ops  = {
        .wakeup_event       = replay_wakeup_event,
        .switch_event       = replay_switch_event,
        .fork_event     = replay_fork_event,
    };

    argc = parse_options(argc, argv, sched_options, sched_usage,
                 PARSE_OPT_STOP_AT_NON_OPTION);
    if (!argc)
        usage_with_options(sched_usage, sched_options);

    /*
     * Aliased to 'perf script' for now:
     */
    if (!strcmp(argv[0], "script"))
        return cmd_script(argc, argv, prefix);

    symbol__init();
    if (!strncmp(argv[0], "rec", 3)) {
        return __cmd_record(argc, argv);
    } else if (!strncmp(argv[0], "lat", 3)) {
        sched.tp_handler = &lat_ops;
        if (argc > 1) {
            argc = parse_options(argc, argv, latency_options, latency_usage, 0);
            if (argc)
                usage_with_options(latency_usage, latency_options);
        }
        setup_sorting(&sched, latency_options, latency_usage);
        return perf_sched__lat(&sched);
    } else if (!strcmp(argv[0], "map")) {
        sched.tp_handler = &map_ops;
        setup_sorting(&sched, latency_options, latency_usage);
        return perf_sched__map(&sched);
    } else if (!strncmp(argv[0], "rep", 3)) {
        sched.tp_handler = &replay_ops;
        if (argc) {
            argc = parse_options(argc, argv, replay_options, replay_usage, 0);
            if (argc)
                usage_with_options(replay_usage, replay_options);
        }
        return perf_sched__replay(&sched);
    } else {
        usage_with_options(sched_usage, sched_options);
    }

    return 0;
}