Merge remote-tracking branches 'asoc/topic/dwc', 'asoc/topic/fallthrough', 'asoc...

[mirror_ubuntu-bionic-kernel.git] / tools / perf / builtin-lock.c

// 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_file file = {
                .path = input_name,
                .mode = PERF_DATA_MODE_READ,
                .force = force,
        };

        session = perf_session__new(&file, 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;
}