builtin-lock.c

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// SPDX-License-Identifier: GPL-2.0
#include <errno.h>
#include <inttypes.h>
#include "builtin.h"
#include "perf.h"

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

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

#include "util/debug.h"
#include "util/session.h"
#include "util/tool.h"
#include "util/data.h"

#include <sys/types.h>
#include <sys/prctl.h>
#include <semaphore.h>
#include <pthread.h>
#include <math.h>
#include <limits.h>

#include <linux/list.h>
#include <linux/hash.h>
#include <linux/kernel.h>

static struct perf_session *session;

/* based on kernel/lockdep.c */
#define LOCKHASH_BITS       12
#define LOCKHASH_SIZE       (1UL << LOCKHASH_BITS)

static struct list_head lockhash_table[LOCKHASH_SIZE];

#define __lockhashfn(key)   hash_long((unsigned long)key, LOCKHASH_BITS)
#define lockhashentry(key)  (lockhash_table + __lockhashfn((key)))

struct lock_stat {
    struct list_head    hash_entry;
    struct rb_node      rb;     /* used for sorting */

    /*
     * FIXME: perf_evsel__intval() returns u64,
     * so address of lockdep_map should be dealed as 64bit.
     * Is there more better solution?
     */
    void            *addr;      /* address of lockdep_map, used as ID */
    char            *name;      /* for strcpy(), we cannot use const */

    unsigned int        nr_acquire;
    unsigned int        nr_acquired;
    unsigned int        nr_contended;
    unsigned int        nr_release;

    unsigned int        nr_readlock;
    unsigned int        nr_trylock;

    /* these times are in nano sec. */
    u64                     avg_wait_time;
    u64         wait_time_total;
    u64         wait_time_min;
    u64         wait_time_max;

    int         discard; /* flag of blacklist */
};

/*
 * States of lock_seq_stat
 *
 * UNINITIALIZED is required for detecting first event of acquire.
 * As the nature of lock events, there is no guarantee
 * that the first event for the locks are acquire,
 * it can be acquired, contended or release.
 */
#define SEQ_STATE_UNINITIALIZED      0         /* initial state */
#define SEQ_STATE_RELEASED  1
#define SEQ_STATE_ACQUIRING 2
#define SEQ_STATE_ACQUIRED  3
#define SEQ_STATE_READ_ACQUIRED 4
#define SEQ_STATE_CONTENDED 5

/*
 * MAX_LOCK_DEPTH
 * Imported from include/linux/sched.h.
 * Should this be synchronized?
 */
#define MAX_LOCK_DEPTH 48

/*
 * struct lock_seq_stat:
 * Place to put on state of one lock sequence
 * 1) acquire -> acquired -> release
 * 2) acquire -> contended -> acquired -> release
 * 3) acquire (with read or try) -> release
 * 4) Are there other patterns?
 */
struct lock_seq_stat {
    struct list_head        list;
    int         state;
    u64         prev_event_time;
    void                    *addr;

    int                     read_count;
};

struct thread_stat {
    struct rb_node      rb;

    u32                     tid;
    struct list_head        seq_list;
};

static struct rb_root       thread_stats;

static struct thread_stat *thread_stat_find(u32 tid)
{
    struct rb_node *node;
    struct thread_stat *st;

    node = thread_stats.rb_node;
    while (node) {
        st = container_of(node, struct thread_stat, rb);
        if (st->tid == tid)
            return st;
        else if (tid < st->tid)
            node = node->rb_left;
        else
            node = node->rb_right;
    }

    return NULL;
}

static void thread_stat_insert(struct thread_stat *new)
{
    struct rb_node **rb = &thread_stats.rb_node;
    struct rb_node *parent = NULL;
    struct thread_stat *p;

    while (*rb) {
        p = container_of(*rb, struct thread_stat, rb);
        parent = *rb;

        if (new->tid < p->tid)
            rb = &(*rb)->rb_left;
        else if (new->tid > p->tid)
            rb = &(*rb)->rb_right;
        else
            BUG_ON("inserting invalid thread_stat\n");
    }

    rb_link_node(&new->rb, parent, rb);
    rb_insert_color(&new->rb, &thread_stats);
}

static struct thread_stat *thread_stat_findnew_after_first(u32 tid)
{
    struct thread_stat *st;

    st = thread_stat_find(tid);
    if (st)
        return st;

    st = zalloc(sizeof(struct thread_stat));
    if (!st) {
        pr_err("memory allocation failed\n");
        return NULL;
    }

    st->tid = tid;
    INIT_LIST_HEAD(&st->seq_list);

    thread_stat_insert(st);

    return st;
}

static struct thread_stat *thread_stat_findnew_first(u32 tid);
static struct thread_stat *(*thread_stat_findnew)(u32 tid) =
    thread_stat_findnew_first;

static struct thread_stat *thread_stat_findnew_first(u32 tid)
{
    struct thread_stat *st;

    st = zalloc(sizeof(struct thread_stat));
    if (!st) {
        pr_err("memory allocation failed\n");
        return NULL;
    }
    st->tid = tid;
    INIT_LIST_HEAD(&st->seq_list);

    rb_link_node(&st->rb, NULL, &thread_stats.rb_node);
    rb_insert_color(&st->rb, &thread_stats);

    thread_stat_findnew = thread_stat_findnew_after_first;
    return st;
}

/* build simple key function one is bigger than two */
#define SINGLE_KEY(member)                      \
    static int lock_stat_key_ ## member(struct lock_stat *one,  \
                     struct lock_stat *two)     \
    {                               \
        return one->member > two->member;           \
    }

SINGLE_KEY(nr_acquired)
SINGLE_KEY(nr_contended)
SINGLE_KEY(avg_wait_time)
SINGLE_KEY(wait_time_total)
SINGLE_KEY(wait_time_max)

static int lock_stat_key_wait_time_min(struct lock_stat *one,
                    struct lock_stat *two)
{
    u64 s1 = one->wait_time_min;
    u64 s2 = two->wait_time_min;
    if (s1 == ULLONG_MAX)
        s1 = 0;
    if (s2 == ULLONG_MAX)
        s2 = 0;
    return s1 > s2;
}

struct lock_key {
    /*
     * name: the value for specify by user
     * this should be simpler than raw name of member
     * e.g. nr_acquired -> acquired, wait_time_total -> wait_total
     */
    const char      *name;
    int         (*key)(struct lock_stat*, struct lock_stat*);
};

static const char       *sort_key = "acquired";

static int          (*compare)(struct lock_stat *, struct lock_stat *);

static struct rb_root       result; /* place to store sorted data */

#define DEF_KEY_LOCK(name, fn_suffix)   \
    { #name, lock_stat_key_ ## fn_suffix }
struct lock_key keys[] = {
    DEF_KEY_LOCK(acquired, nr_acquired),
    DEF_KEY_LOCK(contended, nr_contended),
    DEF_KEY_LOCK(avg_wait, avg_wait_time),
    DEF_KEY_LOCK(wait_total, wait_time_total),
    DEF_KEY_LOCK(wait_min, wait_time_min),
    DEF_KEY_LOCK(wait_max, wait_time_max),

    /* extra comparisons much complicated should be here */

    { NULL, NULL }
};

static int select_key(void)
{
    int i;

    for (i = 0; keys[i].name; i++) {
        if (!strcmp(keys[i].name, sort_key)) {
            compare = keys[i].key;
            return 0;
        }
    }

    pr_err("Unknown compare key: %s\n", sort_key);

    return -1;
}

static void insert_to_result(struct lock_stat *st,
                 int (*bigger)(struct lock_stat *, struct lock_stat *))
{
    struct rb_node **rb = &result.rb_node;
    struct rb_node *parent = NULL;
    struct lock_stat *p;

    while (*rb) {
        p = container_of(*rb, struct lock_stat, rb);
        parent = *rb;

        if (bigger(st, p))
            rb = &(*rb)->rb_left;
        else
            rb = &(*rb)->rb_right;
    }

    rb_link_node(&st->rb, parent, rb);
    rb_insert_color(&st->rb, &result);
}

/* returns left most element of result, and erase it */
static struct lock_stat *pop_from_result(void)
{
    struct rb_node *node = result.rb_node;

    if (!node)
        return NULL;

    while (node->rb_left)
        node = node->rb_left;

    rb_erase(node, &result);
    return container_of(node, struct lock_stat, rb);
}

static struct lock_stat *lock_stat_findnew(void *addr, const char *name)
{
    struct list_head *entry = lockhashentry(addr);
    struct lock_stat *ret, *new;

    list_for_each_entry(ret, entry, hash_entry) {
        if (ret->addr == addr)
            return ret;
    }

    new = zalloc(sizeof(struct lock_stat));
    if (!new)
        goto alloc_failed;

    new->addr = addr;
    new->name = zalloc(sizeof(char) * strlen(name) + 1);
    if (!new->name) {
        free(new);
        goto alloc_failed;
    }

    strcpy(new->name, name);
    new->wait_time_min = ULLONG_MAX;

    list_add(&new->hash_entry, entry);
    return new;

alloc_failed:
    pr_err("memory allocation failed\n");
    return NULL;
}

struct trace_lock_handler {
    int (*acquire_event)(struct perf_evsel *evsel,
                 struct perf_sample *sample);

    int (*acquired_event)(struct perf_evsel *evsel,
                  struct perf_sample *sample);

    int (*contended_event)(struct perf_evsel *evsel,
                   struct perf_sample *sample);

    int (*release_event)(struct perf_evsel *evsel,
                 struct perf_sample *sample);
};

static struct lock_seq_stat *get_seq(struct thread_stat *ts, void *addr)
{
    struct lock_seq_stat *seq;

    list_for_each_entry(seq, &ts->seq_list, list) {
        if (seq->addr == addr)
            return seq;
    }

    seq = zalloc(sizeof(struct lock_seq_stat));
    if (!seq) {
        pr_err("memory allocation failed\n");
        return NULL;
    }
    seq->state = SEQ_STATE_UNINITIALIZED;
    seq->addr = addr;

    list_add(&seq->list, &ts->seq_list);
    return seq;
}

enum broken_state {
    BROKEN_ACQUIRE,
    BROKEN_ACQUIRED,
    BROKEN_CONTENDED,
    BROKEN_RELEASE,
    BROKEN_MAX,
};

static int bad_hist[BROKEN_MAX];

enum acquire_flags {
    TRY_LOCK = 1,
    READ_LOCK = 2,
};

static int report_lock_acquire_event(struct perf_evsel *evsel,
                     struct perf_sample *sample)
{
    void *addr;
    struct lock_stat *ls;
    struct thread_stat *ts;
    struct lock_seq_stat *seq;
    const char *name = perf_evsel__strval(evsel, sample, "name");
    u64 tmp = perf_evsel__intval(evsel, sample, "lockdep_addr");
    int flag = perf_evsel__intval(evsel, sample, "flag");

    memcpy(&addr, &tmp, sizeof(void *));

    ls = lock_stat_findnew(addr, name);
    if (!ls)
        return -ENOMEM;
    if (ls->discard)
        return 0;

    ts = thread_stat_findnew(sample->tid);
    if (!ts)
        return -ENOMEM;

    seq = get_seq(ts, addr);
    if (!seq)
        return -ENOMEM;

    switch (seq->state) {
    case SEQ_STATE_UNINITIALIZED:
    case SEQ_STATE_RELEASED:
        if (!flag) {
            seq->state = SEQ_STATE_ACQUIRING;
        } else {
            if (flag & TRY_LOCK)
                ls->nr_trylock++;
            if (flag & READ_LOCK)
                ls->nr_readlock++;
            seq->state = SEQ_STATE_READ_ACQUIRED;
            seq->read_count = 1;
            ls->nr_acquired++;
        }
        break;
    case SEQ_STATE_READ_ACQUIRED:
        if (flag & READ_LOCK) {
            seq->read_count++;
            ls->nr_acquired++;
            goto end;
        } else {
            goto broken;
        }
        break;
    case SEQ_STATE_ACQUIRED:
    case SEQ_STATE_ACQUIRING:
    case SEQ_STATE_CONTENDED:
broken:
        /* broken lock sequence, discard it */
        ls->discard = 1;
        bad_hist[BROKEN_ACQUIRE]++;
        list_del(&seq->list);
        free(seq);
        goto end;
    default:
        BUG_ON("Unknown state of lock sequence found!\n");
        break;
    }

    ls->nr_acquire++;
    seq->prev_event_time = sample->time;
end:
    return 0;
}

static int report_lock_acquired_event(struct perf_evsel *evsel,
                      struct perf_sample *sample)
{
    void *addr;
    struct lock_stat *ls;
    struct thread_stat *ts;
    struct lock_seq_stat *seq;
    u64 contended_term;
    const char *name = perf_evsel__strval(evsel, sample, "name");
    u64 tmp = perf_evsel__intval(evsel, sample, "lockdep_addr");

    memcpy(&addr, &tmp, sizeof(void *));

    ls = lock_stat_findnew(addr, name);
    if (!ls)
        return -ENOMEM;
    if (ls->discard)
        return 0;

    ts = thread_stat_findnew(sample->tid);
    if (!ts)
        return -ENOMEM;

    seq = get_seq(ts, addr);
    if (!seq)
        return -ENOMEM;

    switch (seq->state) {
    case SEQ_STATE_UNINITIALIZED:
        /* orphan event, do nothing */
        return 0;
    case SEQ_STATE_ACQUIRING:
        break;
    case SEQ_STATE_CONTENDED:
        contended_term = sample->time - seq->prev_event_time;
        ls->wait_time_total += contended_term;
        if (contended_term < ls->wait_time_min)
            ls->wait_time_min = contended_term;
        if (ls->wait_time_max < contended_term)
            ls->wait_time_max = contended_term;
        break;
    case SEQ_STATE_RELEASED:
    case SEQ_STATE_ACQUIRED:
    case SEQ_STATE_READ_ACQUIRED:
        /* broken lock sequence, discard it */
        ls->discard = 1;
        bad_hist[BROKEN_ACQUIRED]++;
        list_del(&seq->list);
        free(seq);
        goto end;
    default:
        BUG_ON("Unknown state of lock sequence found!\n");
        break;
    }

    seq->state = SEQ_STATE_ACQUIRED;
    ls->nr_acquired++;
    ls->avg_wait_time = ls->nr_contended ? ls->wait_time_total/ls->nr_contended : 0;
    seq->prev_event_time = sample->time;
end:
    return 0;
}

static int report_lock_contended_event(struct perf_evsel *evsel,
                       struct perf_sample *sample)
{
    void *addr;
    struct lock_stat *ls;
    struct thread_stat *ts;
    struct lock_seq_stat *seq;
    const char *name = perf_evsel__strval(evsel, sample, "name");
    u64 tmp = perf_evsel__intval(evsel, sample, "lockdep_addr");

    memcpy(&addr, &tmp, sizeof(void *));

    ls = lock_stat_findnew(addr, name);
    if (!ls)
        return -ENOMEM;
    if (ls->discard)
        return 0;

    ts = thread_stat_findnew(sample->tid);
    if (!ts)
        return -ENOMEM;

    seq = get_seq(ts, addr);
    if (!seq)
        return -ENOMEM;

    switch (seq->state) {
    case SEQ_STATE_UNINITIALIZED:
        /* orphan event, do nothing */
        return 0;
    case SEQ_STATE_ACQUIRING:
        break;
    case SEQ_STATE_RELEASED:
    case SEQ_STATE_ACQUIRED:
    case SEQ_STATE_READ_ACQUIRED:
    case SEQ_STATE_CONTENDED:
        /* broken lock sequence, discard it */
        ls->discard = 1;
        bad_hist[BROKEN_CONTENDED]++;
        list_del(&seq->list);
        free(seq);
        goto end;
    default:
        BUG_ON("Unknown state of lock sequence found!\n");
        break;
    }

    seq->state = SEQ_STATE_CONTENDED;
    ls->nr_contended++;
    ls->avg_wait_time = ls->wait_time_total/ls->nr_contended;
    seq->prev_event_time = sample->time;
end:
    return 0;
}

static int report_lock_release_event(struct perf_evsel *evsel,
                     struct perf_sample *sample)
{
    void *addr;
    struct lock_stat *ls;
    struct thread_stat *ts;
    struct lock_seq_stat *seq;
    const char *name = perf_evsel__strval(evsel, sample, "name");
    u64 tmp = perf_evsel__intval(evsel, sample, "lockdep_addr");

    memcpy(&addr, &tmp, sizeof(void *));

    ls = lock_stat_findnew(addr, name);
    if (!ls)
        return -ENOMEM;
    if (ls->discard)
        return 0;

    ts = thread_stat_findnew(sample->tid);
    if (!ts)
        return -ENOMEM;

    seq = get_seq(ts, addr);
    if (!seq)
        return -ENOMEM;

    switch (seq->state) {
    case SEQ_STATE_UNINITIALIZED:
        goto end;
    case SEQ_STATE_ACQUIRED:
        break;
    case SEQ_STATE_READ_ACQUIRED:
        seq->read_count--;
        BUG_ON(seq->read_count < 0);
        if (!seq->read_count) {
            ls->nr_release++;
            goto end;
        }
        break;
    case SEQ_STATE_ACQUIRING:
    case SEQ_STATE_CONTENDED:
    case SEQ_STATE_RELEASED:
        /* broken lock sequence, discard it */
        ls->discard = 1;
        bad_hist[BROKEN_RELEASE]++;
        goto free_seq;
    default:
        BUG_ON("Unknown state of lock sequence found!\n");
        break;
    }

    ls->nr_release++;
free_seq:
    list_del(&seq->list);
    free(seq);
end:
    return 0;
}

/* lock oriented handlers */
/* TODO: handlers for CPU oriented, thread oriented */
static struct trace_lock_handler report_lock_ops  = {
    .acquire_event      = report_lock_acquire_event,
    .acquired_event     = report_lock_acquired_event,
    .contended_event    = report_lock_contended_event,
    .release_event      = report_lock_release_event,
};

static struct trace_lock_handler *trace_handler;

static int perf_evsel__process_lock_acquire(struct perf_evsel *evsel,
                         struct perf_sample *sample)
{
    if (trace_handler->acquire_event)
        return trace_handler->acquire_event(evsel, sample);
    return 0;
}

static int perf_evsel__process_lock_acquired(struct perf_evsel *evsel,
                          struct perf_sample *sample)
{
    if (trace_handler->acquired_event)
        return trace_handler->acquired_event(evsel, sample);
    return 0;
}

static int perf_evsel__process_lock_contended(struct perf_evsel *evsel,
                          struct perf_sample *sample)
{
    if (trace_handler->contended_event)
        return trace_handler->contended_event(evsel, sample);
    return 0;
}

static int perf_evsel__process_lock_release(struct perf_evsel *evsel,
                        struct perf_sample *sample)
{
    if (trace_handler->release_event)
        return trace_handler->release_event(evsel, sample);
    return 0;
}

static void print_bad_events(int bad, int total)
{
    /* Output for debug, this have to be removed */
    int i;
    const char *name[4] =
        { "acquire", "acquired", "contended", "release" };

    pr_info("\n=== output for debug===\n\n");
    pr_info("bad: %d, total: %d\n", bad, total);
    pr_info("bad rate: %.2f %%\n", (double)bad / (double)total * 100);
    pr_info("histogram of events caused bad sequence\n");
    for (i = 0; i < BROKEN_MAX; i++)
        pr_info(" %10s: %d\n", name[i], bad_hist[i]);
}

/* TODO: various way to print, coloring, nano or milli sec */
static void print_result(void)
{
    struct lock_stat *st;
    char cut_name[20];
    int bad, total;

    pr_info("%20s ", "Name");
    pr_info("%10s ", "acquired");
    pr_info("%10s ", "contended");

    pr_info("%15s ", "avg wait (ns)");
    pr_info("%15s ", "total wait (ns)");
    pr_info("%15s ", "max wait (ns)");
    pr_info("%15s ", "min wait (ns)");

    pr_info("\n\n");

    bad = total = 0;
    while ((st = pop_from_result())) {
        total++;
        if (st->discard) {
            bad++;
            continue;
        }
        bzero(cut_name, 20);

        if (strlen(st->name) < 16) {
            /* output raw name */
            pr_info("%20s ", st->name);
        } else {
            strncpy(cut_name, st->name, 16);
            cut_name[16] = '.';
            cut_name[17] = '.';
            cut_name[18] = '.';
            cut_name[19] = '\0';
            /* cut off name for saving output style */
            pr_info("%20s ", cut_name);
        }

        pr_info("%10u ", st->nr_acquired);
        pr_info("%10u ", st->nr_contended);

        pr_info("%15" PRIu64 " ", st->avg_wait_time);
        pr_info("%15" PRIu64 " ", st->wait_time_total);
        pr_info("%15" PRIu64 " ", st->wait_time_max);
        pr_info("%15" PRIu64 " ", st->wait_time_min == ULLONG_MAX ?
               0 : st->wait_time_min);
        pr_info("\n");
    }

    print_bad_events(bad, total);
}

static bool info_threads, info_map;

static void dump_threads(void)
{
    struct thread_stat *st;
    struct rb_node *node;
    struct thread *t;

    pr_info("%10s: comm\n", "Thread ID");

    node = rb_first(&thread_stats);
    while (node) {
        st = container_of(node, struct thread_stat, rb);
        t = perf_session__findnew(session, st->tid);
        pr_info("%10d: %s\n", st->tid, thread__comm_str(t));
        node = rb_next(node);
        thread__put(t);
    };
}

static void dump_map(void)
{
    unsigned int i;
    struct lock_stat *st;

    pr_info("Address of instance: name of class\n");
    for (i = 0; i < LOCKHASH_SIZE; i++) {
        list_for_each_entry(st, &lockhash_table[i], hash_entry) {
            pr_info(" %p: %s\n", st->addr, st->name);
        }
    }
}

static int dump_info(void)
{
    int rc = 0;

    if (info_threads)
        dump_threads();
    else if (info_map)
        dump_map();
    else {
        rc = -1;
        pr_err("Unknown type of information\n");
    }

    return rc;
}

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

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

    if (thread == NULL) {
        pr_debug("problem processing %d event, skipping it.\n",
            event->header.type);
        return -1;
    }

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

    thread__put(thread);

    return err;
}

static void sort_result(void)
{
    unsigned int i;
    struct lock_stat *st;

    for (i = 0; i < LOCKHASH_SIZE; i++) {
        list_for_each_entry(st, &lockhash_table[i], hash_entry) {
            insert_to_result(st, compare);
        }
    }
}

static const struct perf_evsel_str_handler lock_tracepoints[] = {
    { "lock:lock_acquire",   perf_evsel__process_lock_acquire,   }, /* CONFIG_LOCKDEP */
    { "lock:lock_acquired",  perf_evsel__process_lock_acquired,  }, /* CONFIG_LOCKDEP, CONFIG_LOCK_STAT */
    { "lock:lock_contended", perf_evsel__process_lock_contended, }, /* CONFIG_LOCKDEP, CONFIG_LOCK_STAT */
    { "lock:lock_release",   perf_evsel__process_lock_release,   }, /* CONFIG_LOCKDEP */
};

static bool force;

static int __cmd_report(bool display_info)
{
    int err = -EINVAL;
    struct perf_tool eops = {
        .sample      = process_sample_event,
        .comm        = perf_event__process_comm,
        .namespaces  = perf_event__process_namespaces,
        .ordered_events  = true,
    };
    struct perf_data data = {
        .file      = {
            .path = input_name,
        },
        .mode      = PERF_DATA_MODE_READ,
        .force     = force,
    };

    session = perf_session__new(&data, false, &eops);
    if (!session) {
        pr_err("Initializing perf session failed\n");
        return -1;
    }

    symbol__init(&session->header.env);

    if (!perf_session__has_traces(session, "lock record"))
        goto out_delete;

    if (perf_session__set_tracepoints_handlers(session, lock_tracepoints)) {
        pr_err("Initializing perf session tracepoint handlers failed\n");
        goto out_delete;
    }

    if (select_key())
        goto out_delete;

    err = perf_session__process_events(session);
    if (err)
        goto out_delete;

    setup_pager();
    if (display_info) /* used for info subcommand */
        err = dump_info();
    else {
        sort_result();
        print_result();
    }

out_delete:
    perf_session__delete(session);
    return err;
}

static int __cmd_record(int argc, const char **argv)
{
    const char *record_args[] = {
        "record", "-R", "-m", "1024", "-c", "1",
    };
    unsigned int rec_argc, i, j, ret;
    const char **rec_argv;

    for (i = 0; i < ARRAY_SIZE(lock_tracepoints); i++) {
        if (!is_valid_tracepoint(lock_tracepoints[i].name)) {
                pr_err("tracepoint %s is not enabled. "
                       "Are CONFIG_LOCKDEP and CONFIG_LOCK_STAT enabled?\n",
                       lock_tracepoints[i].name);
                return 1;
        }
    }

    rec_argc = ARRAY_SIZE(record_args) + argc - 1;
    /* factor of 2 is for -e in front of each tracepoint */
    rec_argc += 2 * ARRAY_SIZE(lock_tracepoints);

    rec_argv = calloc(rec_argc + 1, sizeof(char *));
    if (!rec_argv)
        return -ENOMEM;

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

    for (j = 0; j < ARRAY_SIZE(lock_tracepoints); j++) {
        rec_argv[i++] = "-e";
        rec_argv[i++] = strdup(lock_tracepoints[j].name);
    }

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

    BUG_ON(i != rec_argc);

    ret = cmd_record(i, rec_argv);
    free(rec_argv);
    return ret;
}

int cmd_lock(int argc, const char **argv)
{
    const struct option lock_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", &force, "don't complain, do it"),
    OPT_END()
    };

    const struct option info_options[] = {
    OPT_BOOLEAN('t', "threads", &info_threads,
            "dump thread list in perf.data"),
    OPT_BOOLEAN('m', "map", &info_map,
            "map of lock instances (address:name table)"),
    OPT_PARENT(lock_options)
    };

    const struct option report_options[] = {
    OPT_STRING('k', "key", &sort_key, "acquired",
            "key for sorting (acquired / contended / avg_wait / wait_total / wait_max / wait_min)"),
    /* TODO: type */
    OPT_PARENT(lock_options)
    };

    const char * const info_usage[] = {
        "perf lock info [<options>]",
        NULL
    };
    const char *const lock_subcommands[] = { "record", "report", "script",
                         "info", NULL };
    const char *lock_usage[] = {
        NULL,
        NULL
    };
    const char * const report_usage[] = {
        "perf lock report [<options>]",
        NULL
    };
    unsigned int i;
    int rc = 0;

    for (i = 0; i < LOCKHASH_SIZE; i++)
        INIT_LIST_HEAD(lockhash_table + i);

    argc = parse_options_subcommand(argc, argv, lock_options, lock_subcommands,
                    lock_usage, PARSE_OPT_STOP_AT_NON_OPTION);
    if (!argc)
        usage_with_options(lock_usage, lock_options);

    if (!strncmp(argv[0], "rec", 3)) {
        return __cmd_record(argc, argv);
    } else if (!strncmp(argv[0], "report", 6)) {
        trace_handler = &report_lock_ops;
        if (argc) {
            argc = parse_options(argc, argv,
                         report_options, report_usage, 0);
            if (argc)
                usage_with_options(report_usage, report_options);
        }
        rc = __cmd_report(false);
    } else if (!strcmp(argv[0], "script")) {
        /* Aliased to 'perf script' */
        return cmd_script(argc, argv);
    } else if (!strcmp(argv[0], "info")) {
        if (argc) {
            argc = parse_options(argc, argv,
                         info_options, info_usage, 0);
            if (argc)
                usage_with_options(info_usage, info_options);
        }
        /* recycling report_lock_ops */
        trace_handler = &report_lock_ops;
        rc = __cmd_report(true);
    } else {
        usage_with_options(lock_usage, lock_options);
    }

    return rc;
}