builtin-sched.c

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// SPDX-License-Identifier: GPL-2.0
#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/cloexec.h"
#include "util/thread_map.h"
#include "util/color.h"
#include "util/stat.h"
#include "util/callchain.h"
#include "util/time-utils.h"

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

#include "util/debug.h"

#include <linux/kernel.h>
#include <linux/log2.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <inttypes.h>

#include <errno.h>
#include <semaphore.h>
#include <pthread.h>
#include <math.h>
#include <api/fs/fs.h>
#include <linux/time64.h>

#include "sane_ctype.h"

#define PR_SET_NAME     15               /* Set process name */
#define MAX_CPUS        4096
#define COMM_LEN        20
#define SYM_LEN         129
#define MAX_PID         1024000

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 "RSDTtZXxKWP"

/* task state bitmask, copied from include/linux/sched.h */
#define TASK_RUNNING        0
#define TASK_INTERRUPTIBLE  1
#define TASK_UNINTERRUPTIBLE    2
#define __TASK_STOPPED      4
#define __TASK_TRACED       8
/* in tsk->exit_state */
#define EXIT_DEAD       16
#define EXIT_ZOMBIE     32
#define EXIT_TRACE      (EXIT_ZOMBIE | EXIT_DEAD)
/* in tsk->state again */
#define TASK_DEAD       64
#define TASK_WAKEKILL       128
#define TASK_WAKING     256
#define TASK_PARKED     512

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;
    int         num_merged;
};

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);

    /* PERF_RECORD_FORK event, not sched_process_fork tracepoint */
    int (*fork_event)(struct perf_sched *sched, union perf_event *event,
              struct machine *machine);

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

#define COLOR_PIDS PERF_COLOR_BLUE
#define COLOR_CPUS PERF_COLOR_BG_RED

struct perf_sched_map {
    DECLARE_BITMAP(comp_cpus_mask, MAX_CPUS);
    int         *comp_cpus;
    bool             comp;
    struct thread_map   *color_pids;
    const char      *color_pids_str;
    struct cpu_map      *color_cpus;
    const char      *color_cpus_str;
    struct cpu_map      *cpus;
    const char      *cpus_str;
};

struct perf_sched {
    struct perf_tool tool;
    const char   *sort_order;
    unsigned long    nr_tasks;
    struct task_desc **pid_to_task;
    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_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, merged_atom_root;
    struct list_head sort_list, cmp_pid;
    bool force;
    bool skip_merge;
    struct perf_sched_map map;

    /* options for timehist command */
    bool        summary;
    bool        summary_only;
    bool        idle_hist;
    bool        show_callchain;
    unsigned int    max_stack;
    bool        show_cpu_visual;
    bool        show_wakeups;
    bool        show_next;
    bool        show_migrations;
    bool        show_state;
    u64     skipped_samples;
    const char  *time_str;
    struct perf_time_interval ptime;
    struct perf_time_interval hist_time;
};

/* per thread run time data */
struct thread_runtime {
    u64 last_time;      /* time of previous sched in/out event */
    u64 dt_run;         /* run time */
    u64 dt_sleep;       /* time between CPU access by sleep (off cpu) */
    u64 dt_iowait;      /* time between CPU access by iowait (off cpu) */
    u64 dt_preempt;     /* time between CPU access by preempt (off cpu) */
    u64 dt_delay;       /* time between wakeup and sched-in */
    u64 ready_to_run;   /* time of wakeup */

    struct stats run_stats;
    u64 total_run_time;
    u64 total_sleep_time;
    u64 total_iowait_time;
    u64 total_preempt_time;
    u64 total_delay_time;

    int last_state;

    char shortname[3];
    bool comm_changed;

    u64 migrations;
};

/* per event run time data */
struct evsel_runtime {
    u64 *last_time; /* time this event was last seen per cpu */
    u32 ncpu;       /* highest cpu slot allocated */
};

/* per cpu idle time data */
struct idle_thread_runtime {
    struct thread_runtime   tr;
    struct thread       *last_thread;
    struct rb_root      sorted_root;
    struct callchain_root   callchain;
    struct callchain_cursor cursor;
};

/* track idle times per cpu */
static struct thread **idle_threads;
static int idle_max_cpu;
static char idle_comm[] = "<idle>";

static u64 get_nsecs(void)
{
    struct timespec ts;

    clock_gettime(CLOCK_MONOTONIC, &ts);

    return ts.tv_sec * NSEC_PER_SEC + 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 = NSEC_PER_SEC;
    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 = NSEC_PER_SEC;
    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;
    static int pid_max;

    if (sched->pid_to_task == NULL) {
        if (sysctl__read_int("kernel/pid_max", &pid_max) < 0)
            pid_max = MAX_PID;
        BUG_ON((sched->pid_to_task = calloc(pid_max, sizeof(struct task_desc *))) == NULL);
    }
    if (pid >= (unsigned long)pid_max) {
        BUG_ON((sched->pid_to_task = realloc(sched->pid_to_task, (pid + 1) *
            sizeof(struct task_desc *))) == NULL);
        while (pid >= (unsigned long)pid_max)
            sched->pid_to_task[pid_max++] = NULL;
    }

    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_desc *));
    BUG_ON(!sched->tasks);
    sched->tasks[task->nr] = task;

    if (verbose > 0)
        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 * NSEC_PER_SEC + ru.ru_utime.tv_usec * NSEC_PER_USEC;
    sum += ru.ru_stime.tv_sec * NSEC_PER_SEC + ru.ru_stime.tv_usec * NSEC_PER_USEC;

    return sum;
}

static int self_open_counters(struct perf_sched *sched, unsigned long cur_task)
{
    struct perf_event_attr attr;
    char sbuf[STRERR_BUFSIZE], info[STRERR_BUFSIZE];
    int fd;
    struct rlimit limit;
    bool need_privilege = false;

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

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

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

    if (fd < 0) {
        if (errno == EMFILE) {
            if (sched->force) {
                BUG_ON(getrlimit(RLIMIT_NOFILE, &limit) == -1);
                limit.rlim_cur += sched->nr_tasks - cur_task;
                if (limit.rlim_cur > limit.rlim_max) {
                    limit.rlim_max = limit.rlim_cur;
                    need_privilege = true;
                }
                if (setrlimit(RLIMIT_NOFILE, &limit) == -1) {
                    if (need_privilege && errno == EPERM)
                        strcpy(info, "Need privilege\n");
                } else
                    goto force_again;
            } else
                strcpy(info, "Have a try with -f option\n");
        }
        pr_err("Error: sys_perf_event_open() syscall returned "
               "with %d (%s)\n%s", fd,
               str_error_r(errno, sbuf, sizeof(sbuf)), info);
        exit(EXIT_FAILURE);
    }
    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;
    int fd;
};

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 = parms->fd;

    zfree(&parms);

    sprintf(comm2, ":%s", this_task->comm);
    prctl(PR_SET_NAME, comm2);
    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;
        parms->fd = self_open_counters(sched, i);
        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 * (sched->replay_repeat - 1) + sched->cpu_usage) / sched->replay_repeat;

    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 * (sched->replay_repeat - 1) +
                     sched->parent_cpu_usage)/sched->replay_repeat;

    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 * (sched->replay_repeat - 1) + delta) / sched->replay_repeat;

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

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

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

#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 / NSEC_PER_MSEC,
        (double)sched->runavg_parent_cpu_usage / NSEC_PER_MSEC);
#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, NSEC_PER_MSEC);
    T1 = get_nsecs();

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

    T0 = get_nsecs();
    sleep_nsecs(NSEC_PER_MSEC);
    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 > 0) {
        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 > 0)
        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,
                 union perf_event *event,
                 struct machine *machine)
{
    struct thread *child, *parent;

    child = machine__findnew_thread(machine, event->fork.pid,
                    event->fork.tid);
    parent = machine__findnew_thread(machine, event->fork.ppid,
                     event->fork.ptid);

    if (child == NULL || parent == NULL) {
        pr_debug("thread does not exist on fork event: child %p, parent %p\n",
                 child, parent);
        goto out_put;
    }

    if (verbose > 0) {
        printf("fork event\n");
        printf("... parent: %s/%d\n", thread__comm_str(parent), parent->tid);
        printf("...  child: %s/%d\n", thread__comm_str(child), child->tid);
    }

    register_pid(sched, parent->tid, thread__comm_str(parent));
    register_pid(sched, child->tid, thread__comm_str(child));
out_put:
    thread__put(child);
    thread__put(parent);
    return 0;
}

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

/*
 * handle runtime stats saved per thread
 */
static struct thread_runtime *thread__init_runtime(struct thread *thread)
{
    struct thread_runtime *r;

    r = zalloc(sizeof(struct thread_runtime));
    if (!r)
        return NULL;

    init_stats(&r->run_stats);
    thread__set_priv(thread, r);

    return r;
}

static struct thread_runtime *thread__get_runtime(struct thread *thread)
{
    struct thread_runtime *tr;

    tr = thread__priv(thread);
    if (tr == NULL) {
        tr = thread__init_runtime(thread);
        if (tr == NULL)
            pr_debug("Failed to malloc memory for runtime data.\n");
    }

    return tr;
}

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__get(thread);
    INIT_LIST_HEAD(&atoms->work_list);
    __thread_latency_insert(&sched->atom_root, atoms, &sched->cmp_pid);
    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, err = -1;
    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, -1, prev_pid);
    sched_in = machine__findnew_thread(machine, -1, next_pid);
    if (sched_out == NULL || sched_in == NULL)
        goto out_put;

    out_events = thread_atoms_search(&sched->atom_root, sched_out, &sched->cmp_pid);
    if (!out_events) {
        if (thread_atoms_insert(sched, sched_out))
            goto out_put;
        out_events = thread_atoms_search(&sched->atom_root, sched_out, &sched->cmp_pid);
        if (!out_events) {
            pr_err("out-event: Internal tree error");
            goto out_put;
        }
    }
    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))
            goto out_put;
        in_events = thread_atoms_search(&sched->atom_root, sched_in, &sched->cmp_pid);
        if (!in_events) {
            pr_err("in-event: Internal tree error");
            goto out_put;
        }
        /*
         * 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))
            goto out_put;
    }
    add_sched_in_event(in_events, timestamp);
    err = 0;
out_put:
    thread__put(sched_out);
    thread__put(sched_in);
    return err;
}

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, -1, pid);
    struct work_atoms *atoms = thread_atoms_search(&sched->atom_root, thread, &sched->cmp_pid);
    u64 timestamp = sample->time;
    int cpu = sample->cpu, err = -1;

    if (thread == NULL)
        return -1;

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

    add_runtime_event(atoms, runtime, timestamp);
    err = 0;
out_put:
    thread__put(thread);
    return err;
}

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");
    struct work_atoms *atoms;
    struct work_atom *atom;
    struct thread *wakee;
    u64 timestamp = sample->time;
    int err = -1;

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

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

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

    /*
     * As we do not guarantee the wakeup event happens when
     * task is out of run queue, also may happen when task is
     * on run queue and wakeup only change ->state to TASK_RUNNING,
     * then we should not set the ->wake_up_time when wake up a
     * task which is on run queue.
     *
     * You WILL be missing events if you've recorded only
     * one CPU, or are only looking at only one, so don't
     * skip in this case.
     */
    if (sched->profile_cpu == -1 && atom->state != THREAD_SLEEPING)
        goto out_ok;

    sched->nr_timestamps++;
    if (atom->sched_out_time > timestamp) {
        sched->nr_unordered_timestamps++;
        goto out_ok;
    }

    atom->state = THREAD_WAIT_CPU;
    atom->wake_up_time = timestamp;
out_ok:
    err = 0;
out_put:
    thread__put(wakee);
    return err;
}

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;
    int err = -1;

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

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

    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++;
    err = 0;
out_put:
    thread__put(migrant);
    return err;
}

static void output_lat_thread(struct perf_sched *sched, struct work_atoms *work_list)
{
    int i;
    int ret;
    u64 avg;
    char max_lat_at[32];

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

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

    if (work_list->num_merged > 1)
        ret = printf("  %s:(%d) ", thread__comm_str(work_list->thread), work_list->num_merged);
    else
        ret = printf("  %s:%d ", thread__comm_str(work_list->thread), work_list->thread->tid);

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

    avg = work_list->total_lat / work_list->nb_atoms;
    timestamp__scnprintf_usec(work_list->max_lat_at, max_lat_at, sizeof(max_lat_at));

    printf("|%11.3f ms |%9" PRIu64 " | avg:%9.3f ms | max:%9.3f ms | max at: %13s s\n",
          (double)work_list->total_runtime / NSEC_PER_MSEC,
         work_list->nb_atoms, (double)avg / NSEC_PER_MSEC,
         (double)work_list->max_lat / NSEC_PER_MSEC,
         max_lat_at);
}

static int pid_cmp(struct work_atoms *l, struct work_atoms *r)
{
    if (l->thread == r->thread)
        return 0;
    if (l->thread->tid < r->thread->tid)
        return -1;
    if (l->thread->tid > r->thread->tid)
        return 1;
    return (int)(l->thread - r->thread);
}

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

        rb_erase(node, root);
        data = rb_entry(node, struct work_atoms, node);
        __thread_latency_insert(&sched->sorted_atom_root, data, &sched->sort_list);
    }
    if (root == &sched->atom_root) {
        root = &sched->merged_atom_root;
        goto again;
    }
}

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;
}

union map_priv {
    void    *ptr;
    bool     color;
};

static bool thread__has_color(struct thread *thread)
{
    union map_priv priv = {
        .ptr = thread__priv(thread),
    };

    return priv.color;
}

static struct thread*
map__findnew_thread(struct perf_sched *sched, struct machine *machine, pid_t pid, pid_t tid)
{
    struct thread *thread = machine__findnew_thread(machine, pid, tid);
    union map_priv priv = {
        .color = false,
    };

    if (!sched->map.color_pids || !thread || thread__priv(thread))
        return thread;

    if (thread_map__has(sched->map.color_pids, tid))
        priv.color = true;

    thread__set_priv(thread, priv.ptr);
    return thread;
}

static int map_switch_event(struct perf_sched *sched, struct perf_evsel *evsel,
                struct perf_sample *sample, struct machine *machine)
{
    const u32 next_pid = perf_evsel__intval(evsel, sample, "next_pid");
    struct thread *sched_in;
    struct thread_runtime *tr;
    int new_shortname;
    u64 timestamp0, timestamp = sample->time;
    s64 delta;
    int i, this_cpu = sample->cpu;
    int cpus_nr;
    bool new_cpu = false;
    const char *color = PERF_COLOR_NORMAL;
    char stimestamp[32];

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

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

    if (sched->map.comp) {
        cpus_nr = bitmap_weight(sched->map.comp_cpus_mask, MAX_CPUS);
        if (!test_and_set_bit(this_cpu, sched->map.comp_cpus_mask)) {
            sched->map.comp_cpus[cpus_nr++] = this_cpu;
            new_cpu = true;
        }
    } else
        cpus_nr = sched->max_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_in = map__findnew_thread(sched, machine, -1, next_pid);
    if (sched_in == NULL)
        return -1;

    tr = thread__get_runtime(sched_in);
    if (tr == NULL) {
        thread__put(sched_in);
        return -1;
    }

    sched->curr_thread[this_cpu] = thread__get(sched_in);

    printf("  ");

    new_shortname = 0;
    if (!tr->shortname[0]) {
        if (!strcmp(thread__comm_str(sched_in), "swapper")) {
            /*
             * Don't allocate a letter-number for swapper:0
             * as a shortname. Instead, we use '.' for it.
             */
            tr->shortname[0] = '.';
            tr->shortname[1] = ' ';
        } else {
            tr->shortname[0] = sched->next_shortname1;
            tr->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 (i = 0; i < cpus_nr; i++) {
        int cpu = sched->map.comp ? sched->map.comp_cpus[i] : i;
        struct thread *curr_thread = sched->curr_thread[cpu];
        struct thread_runtime *curr_tr;
        const char *pid_color = color;
        const char *cpu_color = color;

        if (curr_thread && thread__has_color(curr_thread))
            pid_color = COLOR_PIDS;

        if (sched->map.cpus && !cpu_map__has(sched->map.cpus, cpu))
            continue;

        if (sched->map.color_cpus && cpu_map__has(sched->map.color_cpus, cpu))
            cpu_color = COLOR_CPUS;

        if (cpu != this_cpu)
            color_fprintf(stdout, color, " ");
        else
            color_fprintf(stdout, cpu_color, "*");

        if (sched->curr_thread[cpu]) {
            curr_tr = thread__get_runtime(sched->curr_thread[cpu]);
            if (curr_tr == NULL) {
                thread__put(sched_in);
                return -1;
            }
            color_fprintf(stdout, pid_color, "%2s ", curr_tr->shortname);
        } else
            color_fprintf(stdout, color, "   ");
    }

    if (sched->map.cpus && !cpu_map__has(sched->map.cpus, this_cpu))
        goto out;

    timestamp__scnprintf_usec(timestamp, stimestamp, sizeof(stimestamp));
    color_fprintf(stdout, color, "  %12s secs ", stimestamp);
    if (new_shortname || tr->comm_changed || (verbose > 0 && sched_in->tid)) {
        const char *pid_color = color;

        if (thread__has_color(sched_in))
            pid_color = COLOR_PIDS;

        color_fprintf(stdout, pid_color, "%s => %s:%d",
               tr->shortname, thread__comm_str(sched_in), sched_in->tid);
        tr->comm_changed = false;
    }

    if (sched->map.comp && new_cpu)
        color_fprintf(stdout, color, " (CPU %d)", this_cpu);

out:
    color_fprintf(stdout, color, "\n");

    thread__put(sched_in);

    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 perf_sched__process_fork_event(struct perf_tool *tool,
                      union perf_event *event,
                      struct perf_sample *sample,
                      struct machine *machine)
{
    struct perf_sched *sched = container_of(tool, struct perf_sched, tool);

    /* run the fork event through the perf machineruy */
    perf_event__process_fork(tool, event, sample, machine);

    /* and then run additional processing needed for this command */
    if (sched->tp_handler->fork_event)
        return sched->tp_handler->fork_event(sched, event, machine);

    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)
{
    int err = 0;

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

    return err;
}

static int perf_sched__process_comm(struct perf_tool *tool __maybe_unused,
                    union perf_event *event,
                    struct perf_sample *sample,
                    struct machine *machine)
{
    struct thread *thread;
    struct thread_runtime *tr;
    int err;

    err = perf_event__process_comm(tool, event, sample, machine);
    if (err)
        return err;

    thread = machine__find_thread(machine, sample->pid, sample->tid);
    if (!thread) {
        pr_err("Internal error: can't find thread\n");
        return -1;
    }

    tr = thread__get_runtime(thread);
    if (tr == NULL) {
        thread__put(thread);
        return -1;
    }

    tr->comm_changed = true;
    thread__put(thread);

    return 0;
}

static int perf_sched__read_events(struct perf_sched *sched)
{
    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_migrate_task", process_sched_migrate_task_event, },
    };
    struct perf_session *session;
    struct perf_data data = {
        .file      = {
            .path = input_name,
        },
        .mode      = PERF_DATA_MODE_READ,
        .force     = sched->force,
    };
    int rc = -1;

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

    symbol__init(&session->header.env);

    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);
        if (err) {
            pr_err("Failed to process events, error %d", err);
            goto out_delete;
        }

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

    rc = 0;
out_delete:
    perf_session__delete(session);
    return rc;
}

/*
 * scheduling times are printed as msec.usec
 */
static inline void print_sched_time(unsigned long long nsecs, int width)
{
    unsigned long msecs;
    unsigned long usecs;

    msecs  = nsecs / NSEC_PER_MSEC;
    nsecs -= msecs * NSEC_PER_MSEC;
    usecs  = nsecs / NSEC_PER_USEC;
    printf("%*lu.%03lu ", width, msecs, usecs);
}

/*
 * returns runtime data for event, allocating memory for it the
 * first time it is used.
 */
static struct evsel_runtime *perf_evsel__get_runtime(struct perf_evsel *evsel)
{
    struct evsel_runtime *r = evsel->priv;

    if (r == NULL) {
        r = zalloc(sizeof(struct evsel_runtime));
        evsel->priv = r;
    }

    return r;
}

/*
 * save last time event was seen per cpu
 */
static void perf_evsel__save_time(struct perf_evsel *evsel,
                  u64 timestamp, u32 cpu)
{
    struct evsel_runtime *r = perf_evsel__get_runtime(evsel);

    if (r == NULL)
        return;

    if ((cpu >= r->ncpu) || (r->last_time == NULL)) {
        int i, n = __roundup_pow_of_two(cpu+1);
        void *p = r->last_time;

        p = realloc(r->last_time, n * sizeof(u64));
        if (!p)
            return;

        r->last_time = p;
        for (i = r->ncpu; i < n; ++i)
            r->last_time[i] = (u64) 0;

        r->ncpu = n;
    }

    r->last_time[cpu] = timestamp;
}

/* returns last time this event was seen on the given cpu */
static u64 perf_evsel__get_time(struct perf_evsel *evsel, u32 cpu)
{
    struct evsel_runtime *r = perf_evsel__get_runtime(evsel);

    if ((r == NULL) || (r->last_time == NULL) || (cpu >= r->ncpu))
        return 0;

    return r->last_time[cpu];
}

static int comm_width = 30;

static char *timehist_get_commstr(struct thread *thread)
{
    static char str[32];
    const char *comm = thread__comm_str(thread);
    pid_t tid = thread->tid;
    pid_t pid = thread->pid_;
    int n;

    if (pid == 0)
        n = scnprintf(str, sizeof(str), "%s", comm);

    else if (tid != pid)
        n = scnprintf(str, sizeof(str), "%s[%d/%d]", comm, tid, pid);

    else
        n = scnprintf(str, sizeof(str), "%s[%d]", comm, tid);

    if (n > comm_width)
        comm_width = n;

    return str;
}

static void timehist_header(struct perf_sched *sched)
{
    u32 ncpus = sched->max_cpu + 1;
    u32 i, j;

    printf("%15s %6s ", "time", "cpu");

    if (sched->show_cpu_visual) {
        printf(" ");
        for (i = 0, j = 0; i < ncpus; ++i) {
            printf("%x", j++);
            if (j > 15)
                j = 0;
        }
        printf(" ");
    }

    printf(" %-*s  %9s  %9s  %9s", comm_width,
        "task name", "wait time", "sch delay", "run time");

    if (sched->show_state)
        printf("  %s", "state");

    printf("\n");

    /*
     * units row
     */
    printf("%15s %-6s ", "", "");

    if (sched->show_cpu_visual)
        printf(" %*s ", ncpus, "");

    printf(" %-*s  %9s  %9s  %9s", comm_width,
           "[tid/pid]", "(msec)", "(msec)", "(msec)");

    if (sched->show_state)
        printf("  %5s", "");

    printf("\n");

    /*
     * separator
     */
    printf("%.15s %.6s ", graph_dotted_line, graph_dotted_line);

    if (sched->show_cpu_visual)
        printf(" %.*s ", ncpus, graph_dotted_line);

    printf(" %.*s  %.9s  %.9s  %.9s", comm_width,
        graph_dotted_line, graph_dotted_line, graph_dotted_line,
        graph_dotted_line);

    if (sched->show_state)
        printf("  %.5s", graph_dotted_line);

    printf("\n");
}

static char task_state_char(struct thread *thread, int state)
{
    static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
    unsigned bit = state ? ffs(state) : 0;

    /* 'I' for idle */
    if (thread->tid == 0)
        return 'I';

    return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
}

static void timehist_print_sample(struct perf_sched *sched,
                  struct perf_evsel *evsel,
                  struct perf_sample *sample,
                  struct addr_location *al,
                  struct thread *thread,
                  u64 t, int state)
{
    struct thread_runtime *tr = thread__priv(thread);
    const char *next_comm = perf_evsel__strval(evsel, sample, "next_comm");
    const u32 next_pid = perf_evsel__intval(evsel, sample, "next_pid");
    u32 max_cpus = sched->max_cpu + 1;
    char tstr[64];
    char nstr[30];
    u64 wait_time;

    timestamp__scnprintf_usec(t, tstr, sizeof(tstr));
    printf("%15s [%04d] ", tstr, sample->cpu);

    if (sched->show_cpu_visual) {
        u32 i;
        char c;

        printf(" ");
        for (i = 0; i < max_cpus; ++i) {
            /* flag idle times with 'i'; others are sched events */
            if (i == sample->cpu)
                c = (thread->tid == 0) ? 'i' : 's';
            else
                c = ' ';
            printf("%c", c);
        }
        printf(" ");
    }

    printf(" %-*s ", comm_width, timehist_get_commstr(thread));

    wait_time = tr->dt_sleep + tr->dt_iowait + tr->dt_preempt;
    print_sched_time(wait_time, 6);

    print_sched_time(tr->dt_delay, 6);
    print_sched_time(tr->dt_run, 6);

    if (sched->show_state)
        printf(" %5c ", task_state_char(thread, state));

    if (sched->show_next) {
        snprintf(nstr, sizeof(nstr), "next: %s[%d]", next_comm, next_pid);
        printf(" %-*s", comm_width, nstr);
    }

    if (sched->show_wakeups && !sched->show_next)
        printf("  %-*s", comm_width, "");

    if (thread->tid == 0)
        goto out;

    if (sched->show_callchain)
        printf("  ");

    sample__fprintf_sym(sample, al, 0,
                EVSEL__PRINT_SYM | EVSEL__PRINT_ONELINE |
                EVSEL__PRINT_CALLCHAIN_ARROW |
                EVSEL__PRINT_SKIP_IGNORED,
                &callchain_cursor, stdout);

out:
    printf("\n");
}

/*
 * Explanation of delta-time stats:
 *
 *            t = time of current schedule out event
 *        tprev = time of previous sched out event
 *                also time of schedule-in event for current task
 *    last_time = time of last sched change event for current task
 *                (i.e, time process was last scheduled out)
 * ready_to_run = time of wakeup for current task
 *
 * -----|------------|------------|------------|------
 *    last         ready        tprev          t
 *    time         to run
 *
 *      |-------- dt_wait --------|
 *                   |- dt_delay -|-- dt_run --|
 *
 *   dt_run = run time of current task
 *  dt_wait = time between last schedule out event for task and tprev
 *            represents time spent off the cpu
 * dt_delay = time between wakeup and schedule-in of task
 */

static void timehist_update_runtime_stats(struct thread_runtime *r,
                     u64 t, u64 tprev)
{
    r->dt_delay   = 0;
    r->dt_sleep   = 0;
    r->dt_iowait  = 0;
    r->dt_preempt = 0;
    r->dt_run     = 0;

    if (tprev) {
        r->dt_run = t - tprev;
        if (r->ready_to_run) {
            if (r->ready_to_run > tprev)
                pr_debug("time travel: wakeup time for task > previous sched_switch event\n");
            else
                r->dt_delay = tprev - r->ready_to_run;
        }

        if (r->last_time > tprev)
            pr_debug("time travel: last sched out time for task > previous sched_switch event\n");
        else if (r->last_time) {
            u64 dt_wait = tprev - r->last_time;

            if (r->last_state == TASK_RUNNING)
                r->dt_preempt = dt_wait;
            else if (r->last_state == TASK_UNINTERRUPTIBLE)
                r->dt_iowait = dt_wait;
            else
                r->dt_sleep = dt_wait;
        }
    }

    update_stats(&r->run_stats, r->dt_run);

    r->total_run_time     += r->dt_run;
    r->total_delay_time   += r->dt_delay;
    r->total_sleep_time   += r->dt_sleep;
    r->total_iowait_time  += r->dt_iowait;
    r->total_preempt_time += r->dt_preempt;
}

static bool is_idle_sample(struct perf_sample *sample,
               struct perf_evsel *evsel)
{
    /* pid 0 == swapper == idle task */
    if (strcmp(perf_evsel__name(evsel), "sched:sched_switch") == 0)
        return perf_evsel__intval(evsel, sample, "prev_pid") == 0;

    return sample->pid == 0;
}

static void save_task_callchain(struct perf_sched *sched,
                struct perf_sample *sample,
                struct perf_evsel *evsel,
                struct machine *machine)
{
    struct callchain_cursor *cursor = &callchain_cursor;
    struct thread *thread;

    /* want main thread for process - has maps */
    thread = machine__findnew_thread(machine, sample->pid, sample->pid);
    if (thread == NULL) {
        pr_debug("Failed to get thread for pid %d.\n", sample->pid);
        return;
    }

    if (!sched->show_callchain || sample->callchain == NULL)
        return;

    if (thread__resolve_callchain(thread, cursor, evsel, sample,
                      NULL, NULL, sched->max_stack + 2) != 0) {
        if (verbose > 0)
            pr_err("Failed to resolve callchain. Skipping\n");

        return;
    }

    callchain_cursor_commit(cursor);

    while (true) {
        struct callchain_cursor_node *node;
        struct symbol *sym;

        node = callchain_cursor_current(cursor);
        if (node == NULL)
            break;

        sym = node->sym;
        if (sym) {
            if (!strcmp(sym->name, "schedule") ||
                !strcmp(sym->name, "__schedule") ||
                !strcmp(sym->name, "preempt_schedule"))
                sym->ignore = 1;
        }

        callchain_cursor_advance(cursor);
    }
}

static int init_idle_thread(struct thread *thread)
{
    struct idle_thread_runtime *itr;

    thread__set_comm(thread, idle_comm, 0);

    itr = zalloc(sizeof(*itr));
    if (itr == NULL)
        return -ENOMEM;

    init_stats(&itr->tr.run_stats);
    callchain_init(&itr->callchain);
    callchain_cursor_reset(&itr->cursor);
    thread__set_priv(thread, itr);

    return 0;
}

/*
 * Track idle stats per cpu by maintaining a local thread
 * struct for the idle task on each cpu.
 */
static int init_idle_threads(int ncpu)
{
    int i, ret;

    idle_threads = zalloc(ncpu * sizeof(struct thread *));
    if (!idle_threads)
        return -ENOMEM;

    idle_max_cpu = ncpu;

    /* allocate the actual thread struct if needed */
    for (i = 0; i < ncpu; ++i) {
        idle_threads[i] = thread__new(0, 0);
        if (idle_threads[i] == NULL)
            return -ENOMEM;

        ret = init_idle_thread(idle_threads[i]);
        if (ret < 0)
            return ret;
    }

    return 0;
}

static void free_idle_threads(void)
{
    int i;

    if (idle_threads == NULL)
        return;

    for (i = 0; i < idle_max_cpu; ++i) {
        if ((idle_threads[i]))
            thread__delete(idle_threads[i]);
    }

    free(idle_threads);
}

static struct thread *get_idle_thread(int cpu)
{
    /*
     * expand/allocate array of pointers to local thread
     * structs if needed
     */
    if ((cpu >= idle_max_cpu) || (idle_threads == NULL)) {
        int i, j = __roundup_pow_of_two(cpu+1);
        void *p;

        p = realloc(idle_threads, j * sizeof(struct thread *));
        if (!p)
            return NULL;

        idle_threads = (struct thread **) p;
        for (i = idle_max_cpu; i < j; ++i)
            idle_threads[i] = NULL;

        idle_max_cpu = j;
    }

    /* allocate a new thread struct if needed */
    if (idle_threads[cpu] == NULL) {
        idle_threads[cpu] = thread__new(0, 0);

        if (idle_threads[cpu]) {
            if (init_idle_thread(idle_threads[cpu]) < 0)
                return NULL;
        }
    }

    return idle_threads[cpu];
}

static void save_idle_callchain(struct perf_sched *sched,
                struct idle_thread_runtime *itr,
                struct perf_sample *sample)
{
    if (!sched->show_callchain || sample->callchain == NULL)
        return;

    callchain_cursor__copy(&itr->cursor, &callchain_cursor);
}

static struct thread *timehist_get_thread(struct perf_sched *sched,
                      struct perf_sample *sample,
                      struct machine *machine,
                      struct perf_evsel *evsel)
{
    struct thread *thread;

    if (is_idle_sample(sample, evsel)) {
        thread = get_idle_thread(sample->cpu);
        if (thread == NULL)
            pr_err("Failed to get idle thread for cpu %d.\n", sample->cpu);

    } else {
        /* there were samples with tid 0 but non-zero pid */
        thread = machine__findnew_thread(machine, sample->pid,
                         sample->tid ?: sample->pid);
        if (thread == NULL) {
            pr_debug("Failed to get thread for tid %d. skipping sample.\n",
                 sample->tid);
        }

        save_task_callchain(sched, sample, evsel, machine);
        if (sched->idle_hist) {
            struct thread *idle;
            struct idle_thread_runtime *itr;

            idle = get_idle_thread(sample->cpu);
            if (idle == NULL) {
                pr_err("Failed to get idle thread for cpu %d.\n", sample->cpu);
                return NULL;
            }

            itr = thread__priv(idle);
            if (itr == NULL)
                return NULL;

            itr->last_thread = thread;

            /* copy task callchain when entering to idle */
            if (perf_evsel__intval(evsel, sample, "next_pid") == 0)
                save_idle_callchain(sched, itr, sample);
        }
    }

    return thread;
}

static bool timehist_skip_sample(struct perf_sched *sched,
                 struct thread *thread,
                 struct perf_evsel *evsel,
                 struct perf_sample *sample)
{
    bool rc = false;

    if (thread__is_filtered(thread)) {
        rc = true;
        sched->skipped_samples++;
    }

    if (sched->idle_hist) {
        if (strcmp(perf_evsel__name(evsel), "sched:sched_switch"))
            rc = true;
        else if (perf_evsel__intval(evsel, sample, "prev_pid") != 0 &&
             perf_evsel__intval(evsel, sample, "next_pid") != 0)
            rc = true;
    }

    return rc;
}

static void timehist_print_wakeup_event(struct perf_sched *sched,
                    struct perf_evsel *evsel,
                    struct perf_sample *sample,
                    struct machine *machine,
                    struct thread *awakened)
{
    struct thread *thread;
    char tstr[64];

    thread = machine__findnew_thread(machine, sample->pid, sample->tid);
    if (thread == NULL)
        return;

    /* show wakeup unless both awakee and awaker are filtered */
    if (timehist_skip_sample(sched, thread, evsel, sample) &&
        timehist_skip_sample(sched, awakened, evsel, sample)) {
        return;
    }

    timestamp__scnprintf_usec(sample->time, tstr, sizeof(tstr));
    printf("%15s [%04d] ", tstr, sample->cpu);
    if (sched->show_cpu_visual)
        printf(" %*s ", sched->max_cpu + 1, "");

    printf(" %-*s ", comm_width, timehist_get_commstr(thread));

    /* dt spacer */
    printf("  %9s  %9s  %9s ", "", "", "");

    printf("awakened: %s", timehist_get_commstr(awakened));

    printf("\n");
}

static int timehist_sched_wakeup_event(struct perf_tool *tool,
                       union perf_event *event __maybe_unused,
                       struct perf_evsel *evsel,
                       struct perf_sample *sample,
                       struct machine *machine)
{
    struct perf_sched *sched = container_of(tool, struct perf_sched, tool);
    struct thread *thread;
    struct thread_runtime *tr = NULL;
    /* want pid of awakened task not pid in sample */
    const u32 pid = perf_evsel__intval(evsel, sample, "pid");

    thread = machine__findnew_thread(machine, 0, pid);
    if (thread == NULL)
        return -1;

    tr = thread__get_runtime(thread);
    if (tr == NULL)
        return -1;

    if (tr->ready_to_run == 0)
        tr->ready_to_run = sample->time;

    /* show wakeups if requested */
    if (sched->show_wakeups &&
        !perf_time__skip_sample(&sched->ptime, sample->time))
        timehist_print_wakeup_event(sched, evsel, sample, machine, thread);

    return 0;
}

static void timehist_print_migration_event(struct perf_sched *sched,
                    struct perf_evsel *evsel,
                    struct perf_sample *sample,
                    struct machine *machine,
                    struct thread *migrated)
{
    struct thread *thread;
    char tstr[64];
    u32 max_cpus = sched->max_cpu + 1;
    u32 ocpu, dcpu;

    if (sched->summary_only)
        return;

    max_cpus = sched->max_cpu + 1;
    ocpu = perf_evsel__intval(evsel, sample, "orig_cpu");
    dcpu = perf_evsel__intval(evsel, sample, "dest_cpu");

    thread = machine__findnew_thread(machine, sample->pid, sample->tid);
    if (thread == NULL)
        return;

    if (timehist_skip_sample(sched, thread, evsel, sample) &&
        timehist_skip_sample(sched, migrated, evsel, sample)) {
        return;
    }

    timestamp__scnprintf_usec(sample->time, tstr, sizeof(tstr));
    printf("%15s [%04d] ", tstr, sample->cpu);

    if (sched->show_cpu_visual) {
        u32 i;
        char c;

        printf("  ");
        for (i = 0; i < max_cpus; ++i) {
            c = (i == sample->cpu) ? 'm' : ' ';
            printf("%c", c);
        }
        printf("  ");
    }

    printf(" %-*s ", comm_width, timehist_get_commstr(thread));

    /* dt spacer */
    printf("  %9s  %9s  %9s ", "", "", "");

    printf("migrated: %s", timehist_get_commstr(migrated));
    printf(" cpu %d => %d", ocpu, dcpu);

    printf("\n");
}

static int timehist_migrate_task_event(struct perf_tool *tool,
                       union perf_event *event __maybe_unused,
                       struct perf_evsel *evsel,
                       struct perf_sample *sample,
                       struct machine *machine)
{
    struct perf_sched *sched = container_of(tool, struct perf_sched, tool);
    struct thread *thread;
    struct thread_runtime *tr = NULL;
    /* want pid of migrated task not pid in sample */
    const u32 pid = perf_evsel__intval(evsel, sample, "pid");

    thread = machine__findnew_thread(machine, 0, pid);
    if (thread == NULL)
        return -1;

    tr = thread__get_runtime(thread);
    if (tr == NULL)
        return -1;

    tr->migrations++;

    /* show migrations if requested */
    timehist_print_migration_event(sched, evsel, sample, machine, thread);

    return 0;
}

static int timehist_sched_change_event(struct perf_tool *tool,
                       union perf_event *event,
                       struct perf_evsel *evsel,
                       struct perf_sample *sample,
                       struct machine *machine)
{
    struct perf_sched *sched = container_of(tool, struct perf_sched, tool);
    struct perf_time_interval *ptime = &sched->ptime;
    struct addr_location al;
    struct thread *thread;
    struct thread_runtime *tr = NULL;
    u64 tprev, t = sample->time;
    int rc = 0;
    int state = perf_evsel__intval(evsel, sample, "prev_state");


    if (machine__resolve(machine, &al, sample) < 0) {
        pr_err("problem processing %d event. skipping it\n",
               event->header.type);
        rc = -1;
        goto out;
    }

    thread = timehist_get_thread(sched, sample, machine, evsel);
    if (thread == NULL) {
        rc = -1;
        goto out;
    }

    if (timehist_skip_sample(sched, thread, evsel, sample))
        goto out;

    tr = thread__get_runtime(thread);
    if (tr == NULL) {
        rc = -1;
        goto out;
    }

    tprev = perf_evsel__get_time(evsel, sample->cpu);

    /*
     * If start time given:
     * - sample time is under window user cares about - skip sample
     * - tprev is under window user cares about  - reset to start of window
     */
    if (ptime->start && ptime->start > t)
        goto out;

    if (tprev && ptime->start > tprev)
        tprev = ptime->start;

    /*
     * If end time given:
     * - previous sched event is out of window - we are done
     * - sample time is beyond window user cares about - reset it
     *   to close out stats for time window interest
     */
    if (ptime->end) {
        if (tprev > ptime->end)
            goto out;

        if (t > ptime->end)
            t = ptime->end;
    }

    if (!sched->idle_hist || thread->tid == 0) {
        timehist_update_runtime_stats(tr, t, tprev);

        if (sched->idle_hist) {
            struct idle_thread_runtime *itr = (void *)tr;
            struct thread_runtime *last_tr;

            BUG_ON(thread->tid != 0);

            if (itr->last_thread == NULL)
                goto out;

            /* add current idle time as last thread's runtime */
            last_tr = thread__get_runtime(itr->last_thread);
            if (last_tr == NULL)
                goto out;

            timehist_update_runtime_stats(last_tr, t, tprev);
            /*
             * remove delta time of last thread as it's not updated
             * and otherwise it will show an invalid value next
             * time.  we only care total run time and run stat.
             */
            last_tr->dt_run = 0;
            last_tr->dt_delay = 0;
            last_tr->dt_sleep = 0;
            last_tr->dt_iowait = 0;
            last_tr->dt_preempt = 0;

            if (itr->cursor.nr)
                callchain_append(&itr->callchain, &itr->cursor, t - tprev);

            itr->last_thread = NULL;
        }
    }

    if (!sched->summary_only)
        timehist_print_sample(sched, evsel, sample, &al, thread, t, state);

out:
    if (sched->hist_time.start == 0 && t >= ptime->start)
        sched->hist_time.start = t;
    if (ptime->end == 0 || t <= ptime->end)
        sched->hist_time.end = t;

    if (tr) {
        /* time of this sched_switch event becomes last time task seen */
        tr->last_time = sample->time;

        /* last state is used to determine where to account wait time */
        tr->last_state = state;

        /* sched out event for task so reset ready to run time */
        tr->ready_to_run = 0;
    }

    perf_evsel__save_time(evsel, sample->time, sample->cpu);

    return rc;
}

static int timehist_sched_switch_event(struct perf_tool *tool,
                 union perf_event *event,
                 struct perf_evsel *evsel,
                 struct perf_sample *sample,
                 struct machine *machine __maybe_unused)
{
    return timehist_sched_change_event(tool, event, evsel, sample, machine);
}

static int process_lost(struct perf_tool *tool __maybe_unused,
            union perf_event *event,
            struct perf_sample *sample,
            struct machine *machine __maybe_unused)
{
    char tstr[64];

    timestamp__scnprintf_usec(sample->time, tstr, sizeof(tstr));
    printf("%15s ", tstr);
    printf("lost %" PRIu64 " events on cpu %d\n", event->lost.lost, sample->cpu);

    return 0;
}


static void print_thread_runtime(struct thread *t,
                 struct thread_runtime *r)
{
    double mean = avg_stats(&r->run_stats);
    float stddev;

    printf("%*s   %5d  %9" PRIu64 " ",
           comm_width, timehist_get_commstr(t), t->ppid,
           (u64) r->run_stats.n);

    print_sched_time(r->total_run_time, 8);
    stddev = rel_stddev_stats(stddev_stats(&r->run_stats), mean);
    print_sched_time(r->run_stats.min, 6);
    printf(" ");
    print_sched_time((u64) mean, 6);
    printf(" ");
    print_sched_time(r->run_stats.max, 6);
    printf("  ");
    printf("%5.2f", stddev);
    printf("   %5" PRIu64, r->migrations);
    printf("\n");
}

static void print_thread_waittime(struct thread *t,
                  struct thread_runtime *r)
{
    printf("%*s   %5d  %9" PRIu64 " ",
           comm_width, timehist_get_commstr(t), t->ppid,
           (u64) r->run_stats.n);

    print_sched_time(r->total_run_time, 8);
    print_sched_time(r->total_sleep_time, 6);
    printf(" ");
    print_sched_time(r->total_iowait_time, 6);
    printf(" ");
    print_sched_time(r->total_preempt_time, 6);
    printf(" ");
    print_sched_time(r->total_delay_time, 6);
    printf("\n");
}

struct total_run_stats {
    struct perf_sched *sched;
    u64  sched_count;
    u64  task_count;
    u64  total_run_time;
};

static int __show_thread_runtime(struct thread *t, void *priv)
{
    struct total_run_stats *stats = priv;
    struct thread_runtime *r;

    if (thread__is_filtered(t))
        return 0;

    r = thread__priv(t);
    if (r && r->run_stats.n) {
        stats->task_count++;
        stats->sched_count += r->run_stats.n;
        stats->total_run_time += r->total_run_time;

        if (stats->sched->show_state)
            print_thread_waittime(t, r);
        else
            print_thread_runtime(t, r);
    }

    return 0;
}

static int show_thread_runtime(struct thread *t, void *priv)
{
    if (t->dead)
        return 0;

    return __show_thread_runtime(t, priv);
}

static int show_deadthread_runtime(struct thread *t, void *priv)
{
    if (!t->dead)
        return 0;

    return __show_thread_runtime(t, priv);
}

static size_t callchain__fprintf_folded(FILE *fp, struct callchain_node *node)
{
    const char *sep = " <- ";
    struct callchain_list *chain;
    size_t ret = 0;
    char bf[1024];
    bool first;

    if (node == NULL)
        return 0;

    ret = callchain__fprintf_folded(fp, node->parent);
    first = (ret == 0);

    list_for_each_entry(chain, &node->val, list) {
        if (chain->ip >= PERF_CONTEXT_MAX)
            continue;
        if (chain->ms.sym && chain->ms.sym->ignore)
            continue;
        ret += fprintf(fp, "%s%s", first ? "" : sep,
                   callchain_list__sym_name(chain, bf, sizeof(bf),
                            false));
        first = false;
    }

    return ret;
}

static size_t timehist_print_idlehist_callchain(struct rb_root *root)
{
    size_t ret = 0;
    FILE *fp = stdout;
    struct callchain_node *chain;
    struct rb_node *rb_node = rb_first(root);

    printf("  %16s  %8s  %s\n", "Idle time (msec)", "Count", "Callchains");
    printf("  %.16s  %.8s  %.50s\n", graph_dotted_line, graph_dotted_line,
           graph_dotted_line);

    while (rb_node) {
        chain = rb_entry(rb_node, struct callchain_node, rb_node);
        rb_node = rb_next(rb_node);

        ret += fprintf(fp, "  ");
        print_sched_time(chain->hit, 12);
        ret += 16;  /* print_sched_time returns 2nd arg + 4 */
        ret += fprintf(fp, " %8d  ", chain->count);
        ret += callchain__fprintf_folded(fp, chain);
        ret += fprintf(fp, "\n");
    }

    return ret;
}

static void timehist_print_summary(struct perf_sched *sched,
                   struct perf_session *session)
{
    struct machine *m = &session->machines.host;
    struct total_run_stats totals;
    u64 task_count;
    struct thread *t;
    struct thread_runtime *r;
    int i;
    u64 hist_time = sched->hist_time.end - sched->hist_time.start;

    memset(&totals, 0, sizeof(totals));
    totals.sched = sched;

    if (sched->idle_hist) {
        printf("\nIdle-time summary\n");
        printf("%*s  parent  sched-out  ", comm_width, "comm");
        printf("  idle-time   min-idle    avg-idle    max-idle  stddev  migrations\n");
    } else if (sched->show_state) {
        printf("\nWait-time summary\n");
        printf("%*s  parent   sched-in  ", comm_width, "comm");
        printf("   run-time      sleep      iowait     preempt       delay\n");
    } else {
        printf("\nRuntime summary\n");
        printf("%*s  parent   sched-in  ", comm_width, "comm");
        printf("   run-time    min-run     avg-run     max-run  stddev  migrations\n");
    }
    printf("%*s            (count)  ", comm_width, "");
    printf("     (msec)     (msec)      (msec)      (msec)       %s\n",
           sched->show_state ? "(msec)" : "%");
    printf("%.117s\n", graph_dotted_line);

    machine__for_each_thread(m, show_thread_runtime, &totals);
    task_count = totals.task_count;
    if (!task_count)
        printf("<no still running tasks>\n");

    printf("\nTerminated tasks:\n");
    machine__for_each_thread(m, show_deadthread_runtime, &totals);
    if (task_count == totals.task_count)
        printf("<no terminated tasks>\n");

    /* CPU idle stats not tracked when samples were skipped */
    if (sched->skipped_samples && !sched->idle_hist)
        return;

    printf("\nIdle stats:\n");
    for (i = 0; i < idle_max_cpu; ++i) {
        t = idle_threads[i];
        if (!t)
            continue;

        r = thread__priv(t);
        if (r && r->run_stats.n) {
            totals.sched_count += r->run_stats.n;
            printf("    CPU %2d idle for ", i);
            print_sched_time(r->total_run_time, 6);
            printf(" msec  (%6.2f%%)\n", 100.0 * r->total_run_time / hist_time);
        } else
            printf("    CPU %2d idle entire time window\n", i);
    }

    if (sched->idle_hist && sched->show_callchain) {
        callchain_param.mode  = CHAIN_FOLDED;
        callchain_param.value = CCVAL_PERIOD;

        callchain_register_param(&callchain_param);

        printf("\nIdle stats by callchain:\n");
        for (i = 0; i < idle_max_cpu; ++i) {
            struct idle_thread_runtime *itr;

            t = idle_threads[i];
            if (!t)
                continue;

            itr = thread__priv(t);
            if (itr == NULL)
                continue;

            callchain_param.sort(&itr->sorted_root, &itr->callchain,
                         0, &callchain_param);

            printf("  CPU %2d:", i);
            print_sched_time(itr->tr.total_run_time, 6);
            printf(" msec\n");
            timehist_print_idlehist_callchain(&itr->sorted_root);
            printf("\n");
        }
    }

    printf("\n"
           "    Total number of unique tasks: %" PRIu64 "\n"
           "Total number of context switches: %" PRIu64 "\n",
           totals.task_count, totals.sched_count);

    printf("           Total run time (msec): ");
    print_sched_time(totals.total_run_time, 2);
    printf("\n");

    printf("    Total scheduling time (msec): ");
    print_sched_time(hist_time, 2);
    printf(" (x %d)\n", sched->max_cpu);
}

typedef int (*sched_handler)(struct perf_tool *tool,
              union perf_event *event,
              struct perf_evsel *evsel,
              struct perf_sample *sample,
              struct machine *machine);

static int perf_timehist__process_sample(struct perf_tool *tool,
                     union perf_event *event,
                     struct perf_sample *sample,
                     struct perf_evsel *evsel,
                     struct machine *machine)
{
    struct perf_sched *sched = container_of(tool, struct perf_sched, tool);
    int err = 0;
    int this_cpu = sample->cpu;

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

    if (evsel->handler != NULL) {
        sched_handler f = evsel->handler;

        err = f(tool, event, evsel, sample, machine);
    }

    return err;
}

static int timehist_check_attr(struct perf_sched *sched,
                   struct perf_evlist *evlist)
{
    struct perf_evsel *evsel;
    struct evsel_runtime *er;

    list_for_each_entry(evsel, &evlist->entries, node) {
        er = perf_evsel__get_runtime(evsel);
        if (er == NULL) {
            pr_err("Failed to allocate memory for evsel runtime data\n");
            return -1;
        }

        if (sched->show_callchain && !evsel__has_callchain(evsel)) {
            pr_info("Samples do not have callchains.\n");
            sched->show_callchain = 0;
            symbol_conf.use_callchain = 0;
        }
    }

    return 0;
}

static int perf_sched__timehist(struct perf_sched *sched)
{
    const struct perf_evsel_str_handler handlers[] = {
        { "sched:sched_switch",       timehist_sched_switch_event, },
        { "sched:sched_wakeup",       timehist_sched_wakeup_event, },
        { "sched:sched_wakeup_new",   timehist_sched_wakeup_event, },
    };
    const struct perf_evsel_str_handler migrate_handlers[] = {
        { "sched:sched_migrate_task", timehist_migrate_task_event, },
    };
    struct perf_data data = {
        .file      = {
            .path = input_name,
        },
        .mode      = PERF_DATA_MODE_READ,
        .force     = sched->force,
    };

    struct perf_session *session;
    struct perf_evlist *evlist;
    int err = -1;

    /*
     * event handlers for timehist option
     */
    sched->tool.sample   = perf_timehist__process_sample;
    sched->tool.mmap     = perf_event__process_mmap;
    sched->tool.comm     = perf_event__process_comm;
    sched->tool.exit     = perf_event__process_exit;
    sched->tool.fork     = perf_event__process_fork;
    sched->tool.lost     = process_lost;
    sched->tool.attr     = perf_event__process_attr;
    sched->tool.tracing_data = perf_event__process_tracing_data;
    sched->tool.build_id     = perf_event__process_build_id;

    sched->tool.ordered_events = true;
    sched->tool.ordering_requires_timestamps = true;

    symbol_conf.use_callchain = sched->show_callchain;

    session = perf_session__new(&data, false, &sched->tool);
    if (session == NULL)
        return -ENOMEM;

    evlist = session->evlist;

    symbol__init(&session->header.env);

    if (perf_time__parse_str(&sched->ptime, sched->time_str) != 0) {
        pr_err("Invalid time string\n");
        return -EINVAL;
    }

    if (timehist_check_attr(sched, evlist) != 0)
        goto out;

    setup_pager();

    /* setup per-evsel handlers */
    if (perf_session__set_tracepoints_handlers(session, handlers))
        goto out;

    /* sched_switch event at a minimum needs to exist */
    if (!perf_evlist__find_tracepoint_by_name(session->evlist,
                          "sched:sched_switch")) {
        pr_err("No sched_switch events found. Have you run 'perf sched record'?\n");
        goto out;
    }

    if (sched->show_migrations &&
        perf_session__set_tracepoints_handlers(session, migrate_handlers))
        goto out;

    /* pre-allocate struct for per-CPU idle stats */
    sched->max_cpu = session->header.env.nr_cpus_online;
    if (sched->max_cpu == 0)
        sched->max_cpu = 4;
    if (init_idle_threads(sched->max_cpu))
        goto out;

    /* summary_only implies summary option, but don't overwrite summary if set */
    if (sched->summary_only)
        sched->summary = sched->summary_only;

    if (!sched->summary_only)
        timehist_header(sched);

    err = perf_session__process_events(session);
    if (err) {
        pr_err("Failed to process events, error %d", err);
        goto out;
    }

    sched->nr_events      = evlist->stats.nr_events[0];
    sched->nr_lost_events = evlist->stats.total_lost;
    sched->nr_lost_chunks = evlist->stats.nr_events[PERF_RECORD_LOST];

    if (sched->summary)
        timehist_print_summary(sched, session);

out:
    free_idle_threads();
    perf_session__delete(session);

    return err;
}


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_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 void __merge_work_atoms(struct rb_root *root, struct work_atoms *data)
{
    struct rb_node **new = &(root->rb_node), *parent = NULL;
    struct work_atoms *this;
    const char *comm = thread__comm_str(data->thread), *this_comm;

    while (*new) {
        int cmp;

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

        this_comm = thread__comm_str(this->thread);
        cmp = strcmp(comm, this_comm);
        if (cmp > 0) {
            new = &((*new)->rb_left);
        } else if (cmp < 0) {
            new = &((*new)->rb_right);
        } else {
            this->num_merged++;
            this->total_runtime += data->total_runtime;
            this->nb_atoms += data->nb_atoms;
            this->total_lat += data->total_lat;
            list_splice(&data->work_list, &this->work_list);
            if (this->max_lat < data->max_lat) {
                this->max_lat = data->max_lat;
                this->max_lat_at = data->max_lat_at;
            }
            zfree(&data);
            return;
        }
    }

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

static void perf_sched__merge_lat(struct perf_sched *sched)
{
    struct work_atoms *data;
    struct rb_node *node;

    if (sched->skip_merge)
        return;

    while ((node = rb_first(&sched->atom_root))) {
        rb_erase(node, &sched->atom_root);
        data = rb_entry(node, struct work_atoms, node);
        __merge_work_atoms(&sched->merged_atom_root, data);
    }
}

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

    setup_pager();

    if (perf_sched__read_events(sched))
        return -1;

    perf_sched__merge_lat(sched);
    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);
        thread__zput(work_list->thread);
    }

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

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

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

    return 0;
}

static int setup_map_cpus(struct perf_sched *sched)
{
    struct cpu_map *map;

    sched->max_cpu  = sysconf(_SC_NPROCESSORS_CONF);

    if (sched->map.comp) {
        sched->map.comp_cpus = zalloc(sched->max_cpu * sizeof(int));
        if (!sched->map.comp_cpus)
            return -1;
    }

    if (!sched->map.cpus_str)
        return 0;

    map = cpu_map__new(sched->map.cpus_str);
    if (!map) {
        pr_err("failed to get cpus map from %s\n", sched->map.cpus_str);
        return -1;
    }

    sched->map.cpus = map;
    return 0;
}

static int setup_color_pids(struct perf_sched *sched)
{
    struct thread_map *map;

    if (!sched->map.color_pids_str)
        return 0;

    map = thread_map__new_by_tid_str(sched->map.color_pids_str);
    if (!map) {
        pr_err("failed to get thread map from %s\n", sched->map.color_pids_str);
        return -1;
    }

    sched->map.color_pids = map;
    return 0;
}

static int setup_color_cpus(struct perf_sched *sched)
{
    struct cpu_map *map;

    if (!sched->map.color_cpus_str)
        return 0;

    map = cpu_map__new(sched->map.color_cpus_str);
    if (!map) {
        pr_err("failed to get thread map from %s\n", sched->map.color_cpus_str);
        return -1;
    }

    sched->map.color_cpus = map;
    return 0;
}

static int perf_sched__map(struct perf_sched *sched)
{
    if (setup_map_cpus(sched))
        return -1;

    if (setup_color_pids(sched))
        return -1;

    if (setup_color_cpus(sched))
        return -1;

    setup_pager();
    if (perf_sched__read_events(sched))
        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))
        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) {
            usage_with_options_msg(usage_msg, options,
                    "Unknown --sort key: `%s'", tok);
        }
    }

    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",
        "-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_fork",
        "-e", "sched:sched_wakeup",
        "-e", "sched:sched_wakeup_new",
        "-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);
}

int cmd_sched(int argc, const char **argv)
{
    const char default_sort_order[] = "avg, max, switch, runtime";
    struct perf_sched sched = {
        .tool = {
            .sample      = perf_sched__process_tracepoint_sample,
            .comm        = perf_sched__process_comm,
            .namespaces  = perf_event__process_namespaces,
            .lost        = perf_event__process_lost,
            .fork        = perf_sched__process_fork_event,
            .ordered_events = 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,
        .sort_order       = default_sort_order,
        .replay_repeat        = 10,
        .profile_cpu          = -1,
        .next_shortname1      = 'A',
        .next_shortname2      = '0',
        .skip_merge           = 0,
        .show_callchain       = 1,
        .max_stack            = 5,
    };
    const struct option sched_options[] = {
    OPT_STRING('i', "input", &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_BOOLEAN('f', "force", &sched.force, "don't complain, do it"),
    OPT_END()
    };
    const struct option latency_options[] = {
    OPT_STRING('s', "sort", &sched.sort_order, "key[,key2...]",
           "sort by key(s): runtime, switch, avg, max"),
    OPT_INTEGER('C', "CPU", &sched.profile_cpu,
            "CPU to profile on"),
    OPT_BOOLEAN('p', "pids", &sched.skip_merge,
            "latency stats per pid instead of per comm"),
    OPT_PARENT(sched_options)
    };
    const struct option replay_options[] = {
    OPT_UINTEGER('r', "repeat", &sched.replay_repeat,
             "repeat the workload replay N times (-1: infinite)"),
    OPT_PARENT(sched_options)
    };
    const struct option map_options[] = {
    OPT_BOOLEAN(0, "compact", &sched.map.comp,
            "map output in compact mode"),
    OPT_STRING(0, "color-pids", &sched.map.color_pids_str, "pids",
           "highlight given pids in map"),
    OPT_STRING(0, "color-cpus", &sched.map.color_cpus_str, "cpus",
                    "highlight given CPUs in map"),
    OPT_STRING(0, "cpus", &sched.map.cpus_str, "cpus",
                    "display given CPUs in map"),
    OPT_PARENT(sched_options)
    };
    const struct option timehist_options[] = {
    OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
           "file", "vmlinux pathname"),
    OPT_STRING(0, "kallsyms", &symbol_conf.kallsyms_name,
           "file", "kallsyms pathname"),
    OPT_BOOLEAN('g', "call-graph", &sched.show_callchain,
            "Display call chains if present (default on)"),
    OPT_UINTEGER(0, "max-stack", &sched.max_stack,
           "Maximum number of functions to display backtrace."),
    OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
            "Look for files with symbols relative to this directory"),
    OPT_BOOLEAN('s', "summary", &sched.summary_only,
            "Show only syscall summary with statistics"),
    OPT_BOOLEAN('S', "with-summary", &sched.summary,
            "Show all syscalls and summary with statistics"),
    OPT_BOOLEAN('w', "wakeups", &sched.show_wakeups, "Show wakeup events"),
    OPT_BOOLEAN('n', "next", &sched.show_next, "Show next task"),
    OPT_BOOLEAN('M', "migrations", &sched.show_migrations, "Show migration events"),
    OPT_BOOLEAN('V', "cpu-visual", &sched.show_cpu_visual, "Add CPU visual"),
    OPT_BOOLEAN('I', "idle-hist", &sched.idle_hist, "Show idle events only"),
    OPT_STRING(0, "time", &sched.time_str, "str",
           "Time span for analysis (start,stop)"),
    OPT_BOOLEAN(0, "state", &sched.show_state, "Show task state when sched-out"),
    OPT_STRING('p', "pid", &symbol_conf.pid_list_str, "pid[,pid...]",
           "analyze events only for given process id(s)"),
    OPT_STRING('t', "tid", &symbol_conf.tid_list_str, "tid[,tid...]",
           "analyze events only for given thread id(s)"),
    OPT_PARENT(sched_options)
    };

    const char * const latency_usage[] = {
        "perf sched latency [<options>]",
        NULL
    };
    const char * const replay_usage[] = {
        "perf sched replay [<options>]",
        NULL
    };
    const char * const map_usage[] = {
        "perf sched map [<options>]",
        NULL
    };
    const char * const timehist_usage[] = {
        "perf sched timehist [<options>]",
        NULL
    };
    const char *const sched_subcommands[] = { "record", "latency", "map",
                          "replay", "script",
                          "timehist", NULL };
    const char *sched_usage[] = {
        NULL,
        NULL
    };
    struct trace_sched_handler lat_ops  = {
        .wakeup_event       = latency_wakeup_event,
        .switch_event       = latency_switch_event,
        .runtime_event      = latency_runtime_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,
    };
    unsigned int i;

    for (i = 0; i < ARRAY_SIZE(sched.curr_pid); i++)
        sched.curr_pid[i] = -1;

    argc = parse_options_subcommand(argc, argv, sched_options, sched_subcommands,
                    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);

    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")) {
        if (argc) {
            argc = parse_options(argc, argv, map_options, map_usage, 0);
            if (argc)
                usage_with_options(map_usage, map_options);
        }
        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 if (!strcmp(argv[0], "timehist")) {
        if (argc) {
            argc = parse_options(argc, argv, timehist_options,
                         timehist_usage, 0);
            if (argc)
                usage_with_options(timehist_usage, timehist_options);
        }
        if ((sched.show_wakeups || sched.show_next) &&
            sched.summary_only) {
            pr_err(" Error: -s and -[n|w] are mutually exclusive.\n");
            parse_options_usage(timehist_usage, timehist_options, "s", true);
            if (sched.show_wakeups)
                parse_options_usage(NULL, timehist_options, "w", true);
            if (sched.show_next)
                parse_options_usage(NULL, timehist_options, "n", true);
            return -EINVAL;
        }

        return perf_sched__timehist(&sched);
    } else {
        usage_with_options(sched_usage, sched_options);
    }

    return 0;
}